Helicopter Emergency Medical Service transports in Finland in 2024: a national prospective observational study

Helicopter Emergency Medical Service transports in Finland in 2024: a national prospective observational study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Helicopter Emergency Medical Service transports in Finland in 2024: a national prospective observational study Elina Panula, Pauli Vuorinen, Petri Aaltonen, Riika Merivirta, and 9 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8946151/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Helicopter Emergency Medical Service (HEMS) has been a key component of Finnish Emergency Medical Service since 2012. In recent years, the role of HEMS has evolved due to organizational changes and expanding indications for helicopter transport. In addition, the national HEMS network was extended with the establishment of the first rural physician-staffed HEMS unit, FinnHEMS40 (FH40), in 2022. The aims of this study were to characterize patient groups and clinical features of patients transported by helicopter to university hospitals in Finland, assess the potential time–saving of helicopter transport compared with estimated ground ambulance transport, and describe operational characteristics of FH40 within the national HEMS system. Methods This prospective, observational study was conducted in Finland in 2024. All patients transported by helicopter to university hospitals were included. Primary outcomes were patient characteristics and operational metrics; 30-day survival and neurological outcome were assessed descriptively when available. HEMS physicians recorded patient and mission data using a secure electronic data capture system. Helicopter transport times were recorded, whereas ambulance transport times were estimated. Group comparisons were performed using the Kruskal-Wallis test for continuous variables and Fisher´s exact test for categorical variables. Results In total, 467 of 513 patients (90%) transported by helicopters in 2024 were reported. Most patients were male (293, 63%) and the median age was 64 years (interquartile range (IQR) 44–73). The most common indications for helicopter transport were stroke (200, 43%) and trauma (134, 29%). Helicopter transport times were generally shorter than modelled ambulance transport times. Data for 219 (47%) patients were available at the 30-day follow-up, of whom 183 (84%) were alive. Among survivors, 132 (72%) had a good neurological outcome (Cerebral Performance Category 1–2). Conclusions In 2024, stroke and trauma were the main indications for helicopter transport. Helicopter missions were generally faster than modelled ambulance transports. FH40 accounted for a substantial proportion of long-distance transports to tertiary care. Among patients with follow-up data, survival and neurological outcomes were favorable. Overall, the findings provide an updated national overview of helicopter transports and suggest that helicopter use may facilitate timely access to advanced care, warranting further study of patient-centered outcomes. HEMS Finland transport helicopter ambulance Figures Figure 1 Figure 2 Background Helicopter Emergency Medical Service (HEMS) has been an integral part of Finnish Emergency Medical Services (EMS) since 1992. Following organizational reforms in 2012, the Finnish Health Care Act has designated physician-staffed HEMS as a key component of EMS system with operational responsibility currently assigned to university hospitals within wellbeing services counties. Over the past decade, the role of HEMS in Finland has evolved due to organizational changes and expanding clinical indications. In 2015, the Parliamentary Ombudsman of Finland noted that physician-staffed HEMS did not provide equal coverage for all emergency patients across the country. Ostrobothnia and Southeast Finland were identified as areas of greatest concern. It was also noted that, ongoing healthcare system reforms were likely to increase distances to emergency departments (ED).( 1 ). These developments underscored the importance of HEMS in ensuring timely access to advanced prehospital care across geographically diverse regions. In 2020, HEMS units began transporting selected stroke patients with suspected large vessel occlusion to university hospitals for thrombectomy. Previously, Finnish physician-staffed HEMS were primarily dispatched to trauma cases, out-of-hospital cardiac arrests, and neurological emergencies other than stroke, while conscious stroke patients were not routinely considered candidates for HEMS activation ( 2 ). The national HEMS network has also been extended with the establishment of the first rural physician-staffed HEMS unit, FinnHEMS40 (FH40), in 2022. This unit operates in an area characterized by long distances to tertiary care, illustrating the geographical variability of HEMS operational environments in Finland. In addition, the Finnish healthcare system underwent major structural reforms in 2023, further influencing the organization and delivery of EMS. Against this background, contemporary national data on helicopter transports and patient characteristics within the Finnish HEMS system remain limited. The aims of this study were to 1) characterize the main patient groups and clinical features of patients transported by helicopters to university hospitals in Finland, 2) descriptively assess the potential time-saving of helicopter transport compared with estimated ground ambulance transport, and 3) describe operational characteristics of HEMS units, including FH40, within the national HEMS system. Methods Study design This prospective, researcher-initiated, national observational cohort study collected data on all patients transported by helicopters to university hospitals in Finland during 2024. No interventions, medical treatments or invasive measurements were performed beyond the current emergency treatment protocol. Study protocol was approved by The Regional Ethics Committee of Tampere University Hospital (reference number ETL R23058/2023). The agreements required by law to conduct this study were completed with all wellbeing services counties and the joint authority HUS Group Area. This study is reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. Setting FinnHEMS Ltd., a non-profit organization funded by the Finnish government, organizes HEMS in Finland. A physician, HEMS crew member (HCM) and a pilot form the crews of the six physician-staffed HEMS units. The seventh HEMS unit in Lapland (FH51) is staffed by two HCMs and two pilots. FH40 and FH51 illustrate the geographical variability of HEMS operational environments in Finland, particularly in areas with long distances to tertiary care. FH40 provides an example of a physician-staffed HEMS unit operating outside a university hospital city in Finland. Its Euclidean distance to the nearest university hospital (Tampere University Hospital) is 142 kilometers. FH40 primarily transports patients to central hospitals, with further care provided, when necessary, at university hospitals (Oulu, Kuopio and Tampere). Most HEMS physicians are specialists in anesthesiology and intensive care medicine and have completed an additional two-year education in prehospital emergency medicine; a small proportion are specialists in emergency medicine. HCMs are nurse paramedics or nurses with a bachelor’s degree in nursing and at least 30 European Credit Transfer System (ECTS) credits of additional training focused on advanced-level emergency care. HCMs are required to have a minimum of five years of work experience within EMS or an ED ( 3 ). HEMS reaches approximately 80% of Finnish patients within 30 minutes of receiving an emergency phone call. Dispatchers working at six Emergency Response Centers (ERC) answer emergency calls from mainland Finland. Based on information received from the emergency call, ERC operators conduct a risk analysis that alerts appropriate authorities, including HEMS, to various emergency missions. The climate poses some limitations to helicopters in Finland. During winter, weather conditions often limit flying: during that time, HEMS crews operate short-range missions using rapid response vehicles with the same medical equipment as helicopters. Although HEMS operations are nationally coordinated, individual units differ in terms of catchment area, operational profile, and clinical practices, reflecting geographical characteristics, population density, and regional healthcare structures. Participants This study cohort included all patients transported by helicopter. Of these, only patients with available informed consent were included in the 30-day follow-up analysis; other missing data were handled using complete-case analysis without imputation. Patients transported to central hospitals were excluded, as most helicopter-transported patients in Finland are transported to university hospitals. This restriction was applied to ensure comparability of transport pathways and follow-up. All patients and/or their next of kin were contacted by phone and were asked to provide informed consent to participate in this study. This study involved vulnerable groups and children under 16 years of age. In these cases, informed consent was requested from unconscious patients’ next of kin or, in case of children, from their parents, and when possible, from the children themselves. Separate information letters and consent forms were prepared for adult patients, adult patients’ next of kin, children under 7 years of age and children aged 7–15 years, and parents of children. A data-secure electronic link containing all study information was sent via text or email to all potential participants, regardless of whether they could be reached by phone. Informed consent was obtained electronically, although some participants requested that the information and consent forms by postal mail. The forms were available in Finnish, Swedish and English. Participants and/or their next of kin retained the right to withdraw their participation at any time. As the study involved no interventions, a data permit was also obtained from the Wellbeing Services County of Pirkanmaa to access medical record information for a subset of patients transported by FH30 and FH40 in 2024. Exact numbers of all helicopter-transported patients in Finland in 2024 were obtained from FinnHEMS Ltd. Data collection Patient information is routinely recorded in the FinnHEMS Database (FHDB) during and/or after patient transport in Finland ( 4 ). FHDB served as a template for a study-specific data collection form. Data collected included sex, age, time of the emergency call, indication of dispatch, HEMS time intervals, and treatment provided on scene and during transport. Comorbidities were assessed for patients in 30-day follow-up, and the Charlson Comorbidity Index (CCI) was calculated. CCI was used to describe baseline comorbidity burden and not intended as a measure of acute illness severity. CCI is a weighted index used to estimate one-year mortality risk based on comorbid conditions. Each comorbidity is assigned a weight from 1 to 6 based on its potential impact on mortality, and the total CCI score is calculated by summing these weights. Higher CCI scores indicate a greater burden of comorbidity. As ground ambulances did not transport these patients to hospital, ambulance transport times were not directly observed but estimated. Because exact scene addresses were unavailable, distances were calculated using Google Maps from the nearest township to the nearest university hospital. Estimated ambulance transporttimes were derived assuming an average driving speed of 95 kilometers per hour with lights and sirens. Data were collected using a secure data capture software, Research Electronic Data Capture (REDCap). All HEMS bases were provided with an electronic link, and Quick Response (QR) code to complete the study form. Data collection started on January 1st and ended on December 31st, 2024. Due to delays related to agreement issues, only three HEMS bases (FH30, FH40 and FH60) could begin data collection on January 1st. Others started between January 8th and March 18th (Fig. 1 ). Patient outcomes Patient outcomes were followed for one month after helicopter transport if informed consent was obtained. Research physicians from each HEMS base entered patient information into a separate REDCap form regarding the hospital stay. This form included information about the length of the overall hospital stay, specifically the intensive care unit (ICU) stay, procedures performed on the patient during the hospital stay, and the neurological outcome at one month after helicopter transport. Neurological outcome was assessed by the medical director of each HEMS unit using the electronic health record system and categorized according to the Cerebral Performance Category (CPC) score. CPC is a five-point scale commonly used to describe neurological outcomes after cardiac arrest, with scores 1– 2 considered good and 3–5 poor. CPC was used as pragmatic, generic measure of neurological outcome across heterogenous patient groups, as the predominant patient group was not known at the study outset. We also assessed the population-adjusted transport rates for each HEMS unit. Finland is divided into 19 administrative regions, and HEMS operational areas do not fully correspond to these regional boundaries, with some units covering overlapping or partial regions. Therefore, exact population figures for each HEMS unit´s catchment area were not available. Population estimates were based on regional statistics from Statistics Finland ( 5 ) and estimated population numbers were used in the analysis. Statistics Statistical analyses were performed using IBM SPSS Statistics for Mac 30.0.0.0 (171) (IBM Corp. Armonk, NY, USA). Study populations were characterized using descriptive statistics. Transport times are presented as medians with interquartile ranges (IQR 25th – 75th percentiles). Group comparisons were performed using the Kruskal-Wallis test for continuous variables and Fisher´s exact test for categorical variables. A p-value < 0.05 was considered significant. Results Altogether, 604 patients were transported by helicopters to central and university hospitals in Finland in 2024. Of these, 516 patients (85%) were transported to university hospitals and constituted the primary study population. Complete transport data were available for 467 patients (90%). Follow-up data at 30 days were available for 219 patients (47%). Of these, informed consent was obtained from 165 patients (35% of the primary study population) and/or their next of kin, an additional 54 patients were included based on data use agreement with the Wellbeing Services County of Pirkanmaa. Figure 2 illustrates the flow of patient inclusion. Most patients transported by helicopters were male (293 [63%]). The median age was 64 years (IQR 44–73), with trauma patients having a median age of 43 years (IQR 21–64) and stroke patients a median age of 69 years (IQR 60–75). CCI was 0–3 in most cases (171/220, 78%). The three most common indications for helicopter transports were 1) stroke (200, 43%), 2) trauma (137, 29%) and 3) neurological causes excluding stroke (45, 9.6%) (Table 1 ). Table 2 shows the indications of transports by helicopter and the number of patients transported to university hospitals by each HEMS unit. Among the three most common indications of helicopter transport, the proportion of patients transported for neurological conditions other than stroke varied across HEMS units (p = 0.02). No difference was observed in transports due to trauma (p = 0.09) or stroke (p = 0.19). Table 1 Indications of HEMS transports in Finland in 2024 (N = 467) Indication of HEMS transport Number % Stroke 200 43 Trauma 137 29 Neurological (excluding stroke) 41 8.8 OHCA* 27 5.8 Chest pain 21 4.5 Intoxication/RDS**/infection 10 2.1 Aortic catastrophe 9 1.9 Other*** 13 3.4 Combined**** 9 1.9 *OHCA = out-of-hospital cardiac arrest ** RDS = respiratory distress syndrome *** Other includes rare indications (each n ≤ 2), such as cardiac arrhythmia, anaphylaxis, snake bite, hypoglycemia, and postoperative complications. **** Combined indicates missions with more than one primary indication. Percentages are calculated from total N = 467 unless otherwise stated. Table 2 Main indications for helicopter transport by HEMS unit Indication HEMS unit FH10 (n = 120) FH20 (n = 37) FH30 (n = 40) FH40 (n = 65) FH50 (n = 49) FH51 (n = 39) FH60 (n = 117) Stroke, n (%) 49 (41) 10 (27) 17 (43) 31 (48) 20 (41) 13 (36) 59 (50) Trauma, n (%) 37 (31) 12 (32) 9 (23) 24 (37) 13 (27) 17 (44) 25 (21) Other neurological, n (%) 7 (5.8) 1 (2.7) 3 (7.5) 2 (3.1) 4 (8.2) 4 ( 10 ) 20 (17) OHCA*, n (%) 9 (7.5) 1 (2.7) 7 (18) 0 (0.0) 4 (8.2) 1 (2.6) 5 (4.3) Other, n (%) 18 (15) 13 (35) 4 ( 10 ) 6 ( 9 ) 8 (16) 4 ( 10 ) 8 ( 7 ) *Out of Hospital Cardiac Arrest Most (262, 56%) of the patients were transported during the summer months (May –August), while January (10, 2.1%), February (9, 1.9%), November (21, 4.5%) and December (23, 4.9%) had the fewest helicopter transports. Median transport times varied across HEMS units, with FH51 exhibiting the longest transport times. Units located in university hospital cities generally had shorter transport times. Estimated ground ambulance transport times are presented in Table 3 for comparison. Table 3 Median helicopter and estimated ambulance transport times by HEMS unit. FH unit Helicopter Ambulance Δ Median (IQR) Median (IQR) FH10 23 (18–34) 57 (36–86) 34 FH20 19 (18–24) 47 (15–59) 28 FH30 25 (22–30) 61 (50–87) 36 FH40 48 (41–56) 113 (107–151) 65 FH50 44 (35–52) 89 (70–119) 45 FH51 71 (55–83) 181 (140–222) 110 FH60 31 (25–36) 79 (64–100) 48 *FH=FinnHEMS Δ = difference between median helicopter and estimated ambulance transport times Helicopter transport times differed between HEMS units (Kruskal–Wallis test, p < 0.001). Ground ambulance transport times are based on standardized estimates. Population-adjusted transport rates varied between HEMS units, with generally higher rates observed in units operating in areas with longer distances to tertiary care and lower population density (Table 4 ). Table 4 Population-adjusted number of helicopter transports by HEMS unit. Base Population (N) Patients transported (n) Patients/100 000 population (n) FH10 1 782 000 120 6.7 FH20 495 000 37 7.4 FH30 548 000 40 7.3 FH40 440 000 65 15 FH50 420 000 49 12 FH51 176 000 39 22 FH60 378 200 117 31 Patient treatment at the scene and 30-day follow-up HEMS physicians did not perform any treatment procedures in most missions (318/467, 68%). Patient’s clinical condition remained unchanged or improved in 445 of 467 (95%) cases during transport. Airway management was the most common on-scene intervention (113/467, 24%), most often involving endotracheal intubation (97/113, 86%). Other frequently performed procedures included the use of ultrasound (45/467, 9.6%) and spinal immobilization (35/467, 7.4%). Among patients requiring airway management, rocuronium was the most commonly used neuromuscular blocking agent 89/113 (79%) and was always combined with a sedative. The most frequently administered sedatives were fentanyl (79/113, 70%), S-ketamine (72/113, 64%) and propofol (35/113, 31%). In four (3.5%) cases, no prior medication was administered before intubation. Most intubated patients (70/97, 72%) received continuous propofol-infusion during transport. Regarding hemodynamic management, the most frequent procedures among all patients were intravenous cannulation (207, 44%) and arterial cannulation (75, 16%). Noradrenaline was the most administered vasoactive agent (76, 16%). Blood products (red blood cells and lyophilized plasma) were given to 24 (5.1%) patients and one patient received low-titer type ORh+ whole blood because of ongoing whole blood research. Most patients in 30-day follow-up (135/219, 61%), underwent computed tomography scan in ED. Interventional radiology procedures were conducted on 54 (25%) patients and surgical procedures on 37 (17%). In four (1.8%) cases, life-sustaining treatment was withdrawn in the ED. After hospital admission and the performed procedures, 96 (44%) of patients were managed in ICUs. The mean length of stay in the ICU was 4.9 [SD 5.9] days. Patients were mainly discharged to central hospitals (61, 28%) or home (48, 22%). For a one-month follow up-period, the mean length of overall stay at hospital(s) was 9.4 [SD 10] days. Most of the follow-up patients (183, 84%), were alive after a month of helicopter transport, and the neurological outcome was good (CPC 1–2) in most patients (132, 72%). Assistance with all daily activities (CPC 3) was needed by 47 (26%) of patients. Discussion This study was primarily descriptive and aimed to provide a contemporary national overview of helicopter transports to university hospitals in Finland. The findings offer insight into current patient characteristics, transport patterns, and operational features within the Finnish HEMS system. Compared with earlier Finnish HEMS reports ( 2 ), in which trauma constituted the most common patient group, stroke was the leading indication for helicopter transport in 2024. This change may indicate an ongoing shift in HEMS utilization toward time-critical neurological conditions, likely influenced by organizational reforms and updated dispatch practices. The predominance of male patients and the observed age distribution—particularly the younger age of trauma patients and older age of stroke patients—are consistent with previously established patterns in HEMS transport and illustrate the heterogeneity of clinical presentations encountered by HEMS units. The CCI was predominantly low, indicating that most helicopter-transported patients had limited comorbidity burden, which is consistent with the acute nature of conditions that typically require helicopter transport. Together, these findings characterize the contemporary profile of helicopter-transported patients within the Finnish HEMS system. Geographic variation and transport times Transport times by both helicopter and estimated ground ambulance increased with distance to tertiary care hospitals, reflecting geographical variation in access to advanced care across Finland. In areas with longer distances to university hospitals, HEMS units transported a higher proportion of patients by helicopter when adjusted for population size. This suggests that the utilization of helicopter transport is influenced by regional geography and accessibility rather than solely by patient-related factors. These findings highlight the role of HEMS in addressing geographical disparities in access to tertiary care, particularly in remote and sparsely populated regions. Regional variation within the national HEMS system Some Finnish HEMS units operate in geographically distinct environments characterized by long distances to tertiary care university hospitals. FH40, similar to FH51, serves a predominantly rural central hospital region where long transport distances are inherent to the operational setting. As a result, patients transported by FH40 had longer median transport times than those transported by HEMS units located in university hospital cities. However, these estimates should be interpreted cautiously, as HEMS operational areas do not fully correspond to administrative regions and population figures are therefore approximate. When adjusted for population size, FH40 transported a relatively high number of patients by helicopter. Similar patterns were observed in other regions with longer distances to tertiary care, including FH51 and FH60, which operate in regions with varying population density and distances to tertiary care. These findings illustrate how regional factors, including distance to tertiary care, population density, and accessibility of university hospitals, influence HEMS mission profiles and transport patterns within the national system. Rather than representing a fundamentally different model of HEMS utilization, FH40 may illustrate how helicopter transport can mitigate geographical barriers to tertiary care in certain regions. However, FH40 should be interpreted as one example within the broader national HEMS system rather than as a distinct model of HEMS utilization. Prehospital interventions and system-level role of HEMS Most patients (67%) underwent no procedures during HEMS missions. In Finland, ground ambulance units often reach the patient before HEMS and may initiate initial treatment procedures prior to HEMS arrival, which may partly explain the relatively low number of procedures performed by HEMS physicians. This finding may also reflect the role of HEMS in facilitating rapid transport to tertiary care rather than providing extensive on-scene interventions. Overall, the observed pattern of prehospital interventions suggests that helicopter transport in Finland is frequently used as a logistical resource in time-critical situations, while advanced medical procedures are performed selectively when clinically indicated. The distribution and frequency of procedures were broadly consistent with national registry data ( 2 ). Survival and outcomes In the present study, the median age of all helicopter-transported patients was 64 years, which is broadly comparable to previously reported mean ages of ICU patients in Finland (approximately 62 years) and patients treated by EMS (66 years) ( 6 , 7 ). Among patients with available follow-up data, nearly half (44%) required ICU-level care, indicating that helicopter-transported patients represented a population with substantial acute care needs. The mean duration of ICU stay was 4.9 days in this study, whereas previous Finnish registry data have reported an average ICU stay of approximately 1.5 days ( 8 ). This likely reflects selection of more severely ill patients rather than an effect of helicopter transport. Most patients with available follow-up data survived the first month after helicopter transport, and the majority demonstrated favorable neurological outcomes. However, these findings should be interpreted cautiously due to the limited follow-up rate and potential selection bias. The observational design of the study does not allow causal conclusions regarding the impact of helicopter transport on survival or neurological outcomes. Previous studies have suggested that HEMS transport may be associated with improved outcomes in selected patient populations, particularly when rapid access to tertiary care is critical ( 9 , 10 ). However, reported results are inconsistent and confounded by differences in patient severity, distance, and dispatch criteria. For example, a large Swedish registry study reported lower 30-day mortality among trauma patients transported by HEMS compared with ground ambulance, although neurological outcomes at discharge were less favorable among HEMS patients ( 11 ). These findings illustrate the complexity of interpreting outcome measures in heterogeneous prehospital populations and highlight the influence of confounding factors such as injury severity, distance to hospital, and selection bias. The question of which patient groups benefit most from physician-staffed HEMS or helicopter transport remains unresolved. Variability in HEMS systems, dispatch criteria, and staffing models across countries complicates direct comparisons and limits the generalizability of findings. Galvagno et al. ( 12 ) have noted that, although results vary, improved survival is often observed in HEMS populations when analyses adjust for confounding factors such as severity and transport distance. Potential benefits are likely multifactorial, involving transport speed, crew expertise, and integration within regional trauma and stroke systems. In this study, only one patient with sepsis was identified, and no cases of septic shock or arrhythmia-related shock were observed, despite these conditions having been considered potential indications for rapid helicopter transport in Finnish prehospital practice. This observation raises questions about current dispatch patterns and the extent to which HEMS resources reach critically ill patient groups beyond trauma and stroke. Previous evidence from sepsis populations has shown that although helicopter transport may reduce transfer times, this does not necessarily translate into improved mortality or secondary outcomes ( 13 ), underscoring the complexity of linking time savings to patient-centered outcomes. Strengths and limitations A key strength of this study is its prospective design, which enabled the collection of data on predefined clinical and operational variables. In addition, outcome data were obtained beyond routine registry information, allowing assessment of survival and neurological outcomes that would not have been available from the FHDB alone. This study has several limitations. First, only patients transported by helicopter to university hospitals were included. While this limits generalizability, it also enables more consistent follow-up within tertiary care settings. Although university hospital transports accounted for the majority of helicopter missions in Finland in 2024, the exclusion of central hospital transports may introduce selection bias, which should be taken into account when interpreting the findings. Second, ground ambulance transport times were estimated rather than directly measured, which introduces uncertainty in comparisons between transport modalities. In contrast, helicopter transport times were based on recorded mission data, providing accurate measurements for HEMS transports. Third, follow-up data were incomplete, as informed consent was obtained for only a subset of patients. Although additional data access for two HEMS units increased the proportion of patients with 30-day outcome data, missing follow-up remains a potential source of bias and limits the interpretation of outcome findings. Finally, patient data were entered manually, which may have led to occasional inaccuracies in data recording. Conclusions In 2024, stroke and trauma were the main indications for helicopter transport. Helicopter missions were generally faster than modelled ambulance transports. FH40 accounted for a substantial proportion of long-distance transports to tertiary care. Among patients with follow-up data, survival and neurological outcomes were favorable. Overall, the findings provide an updated national overview of helicopter transports and suggest that helicopter use may facilitate timely access to advanced care. Further studies are warranted to assess patient-centered outcomes. Abbreviations CCI Charlson Comorbidity Index CPC Cerebral Performance Category ECTS European Credit Transfer System ED Emergency Department EMS Emergency Medical Services ERC Emergency Response Center FH FinnHEMS FHDB FinnHEMS Database GDPR General Data Protection Regulation HCM HEMS Crew Member HEMS Helicopter Emergency Medical Services ICU intensive care unit IFR instrument flight rules IQR interquartile range OHCA Out-of-Hospital Cardiac Arrest RDS respiratory distress syndrome SD standard deviation VFR visual flight rules Declarations Ethics approval and consent to participate The Regional Ethics Committee of Tampere University Hospital (ETL R23058) approved this study. All procedures were performed in accordance with the Declaration of Helsinki and its later amendments. Consent for publication Not applicable Availability of data and materials The datasets generated and/or analyzed during the current study are not publicly available due to concerns that individual privacy could be compromised but are available from the corresponding author on reasonable request. Competing interests The authors declare no competing interests. Funding This study was financially supported by the Competitive State Research Financing of the Expert Responsibility Area of Tampere University Hospital (Grant No. 9AC011). The funding body had no role in the design, collection, analysis, interpretation of the data, or manuscript writing. Authors’ contributions EP: Conceptualization, Methodology, Investigation, Data curation, Formal analysis, Writing—original draft. PV: Writing—review and editing. PA: Data collecting, Writing—review and editing. RM: Data collecting, Writing—review and editing. MM: Data collecting, Writing—review and editing. TP: Data collecting, Writing—review and editing. JP: Data collecting, Writing—review and editing. JPK: Data collecting, Writing—review and editing. PS: Data collecting, Writing—review and editing. PT: Data collecting, Writing—review and editing. HH: Formal analysis, Writing—review and editing. SL: Conceptualization, Methodology, Supervision, Writing—review and editing. SH: Conceptualization, Methodology, Supervision, Writing—review and editing. All the authors have read previous versions of the manuscript and approved the final manuscript. Acknowledgements We express our deepest gratitude to all HEMS physicians working in FH10, FH20, FH30, FH40, FH50 and FH60 and nurse paramedics in FH51 for your participation in data collection in 2024. We would also like to express our sincere appreciation to Minna Ala-Karvia, the study coordinator, for her excellent assistance in preparing and launching this study, as well as her invaluable support in securing all necessary study approvals. References Ministry of Social Affairs and Health. Lääkärihelikopteritoiminta 2030-luvulle: esitys valtion lääkärihelikopteritoiminnan strategiaksi. Finland. 2023. Available from: https://urn.fi/URN:ISBN:978-952-00-4241-7 . (accessed March 15, 2025). Saviluoto A, Björkman J, Olkinuora A, Virkkunen I, Kirves H, Setälä P, et al. The first seven years of nationally organized helicopter emergency medical services in Finland - the data from quality registry. Scand J Trauma Resusc Emerg Med. 2020;28(1):46. 10.1186/s13049-020-00739-4 . FinnHEMS Ltd. Haemme ensihoitajia lääkärihelikopteriin. Available from: https://finnhems.fi/ajankohtaista/haemme-ensihoitajia-laakarihelikopteriin/ (accessed Jul 21, 2025). Heino A, Iirola T, Raatiniemi L, Nurmi J, Olkinuora A, Laukkanen-Nevala P, et al. The reliability and accuracy of operational system data in a nationwide helicopter emergency medical services mission database. BMC Emerg Med. 2019;19(1). 10.1186/S12873-019-0265-Y . Statistics Finland. Population and society. Available from: https://stat.fi/tup/suoluk/suoluk_vaesto.html#vaestotietoja-maakunnittain (accessed November 23, 2025). Reinikainen M, Uusaro A, Niskanen M, Ruokonen E. Intensive care of the elderly in Finland. Acta Anaesthesiol Scand. 2007;51(5):522–9. 10.1111/J.1399-6576.2007.01274.X . Aitavaara-Anttila M, Liisanantti J, Ehrola A, Spalding M, Ala-Kokko T, Raatiniemi L. Use of prehospital emergency medical services according to income of residential area. Emerg Med J. 2020;37(7):429–33. 10.1136/EMERMED-2019-208834 . Jäntti S, Ponkilainen V, Kuitunen I, Uimonen MM, Huttunen T, Mattila VM. Intensive care unit admissions with and without COVID-19 in Finland from 2017 to 2021: a retrospective register-based study. BMC Anesthesiol. 2023;23(1):1–7. 10.1186/S12871-023-02207-9/TABLES/2 . Ackermann A, Pappinen J, Nurmi J, Nordquist H, Saviluoto A, Mannila S, et al. A scenario based approach to optimizing cost-effectiveness of physician-staffed Helicopter Emergency Medical Services compared to ground-based Emergency Medical Services in Finland. Scand J Trauma Resusc Emerg Med. 2024;32(1):60. 10.1186/S13049-024-01231-Z/TABLES/2 . Lavery MD, Aulakh A, Christian MD. Benefits of targeted deployment of physician-led interprofessional pre-hospital teams on the care of critically Ill and injured patients: a systematic review and meta-analysis. Scand J Trauma Resusc Emerg Med. 2025;33(1). 10.1186/S13049-024-01298-8 . Lapidus O, Rubenson Wahlin R, Bäckström D. Trauma patient transport to hospital using helicopter emergency medical services or road ambulance in Sweden: a comparison of survival and prehospital time intervals. Scand J Trauma Resusc Emerg Med. 2023;31(1). 10.1186/S13049-023-01168-9 . Galvagno SM. Comparative effectiveness of helicopter emergency medical services compared to ground emergency medical services. Crit Care. 2013;17(4). 10.1186/CC12779 . Kashyap R, Anderson PW, Vakil A, Russi CS, Cartin-Ceba R. A retrospective comparison of helicopter transport versus ground transport in patients with severe sepsis and septic shock. Int J Emerg Med. 2016;9(1). 10.1186/S12245-016-0115-6 . Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8946151","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":601536242,"identity":"306bfcb3-bdb0-4eba-8e5a-704f1a4b0c8d","order_by":0,"name":"Elina Panula","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6ElEQVRIiWNgGAWjYDACdsYGKIu5geEDkGJjYHxwAK8WZrgWxgbGGQkgLcwGBLTAWYwNzDwJYCEDvDr4mZnbHvxguCNvLpHY+Nn2x+E8PqDFeG2RbGZsN+xheGa4c0Zis3ROwuFioMMY8GoxOMzYJsHDcJhxw43EBpCWxDYG/gN4tdgDtUj+YThsD9TS/NsCrIWQLcyMbdJAWxKBWtqkGYjRIgG0RVrG4FnyhjMP2yx70tIT25gJaOFvb38m+abiju2G48mHb/ywsU6c397M/AGfFqjzkI1lxqUKFeB1ySgYBaNgFIx0AACMBEpR6RABkQAAAABJRU5ErkJggg==","orcid":"","institution":"Tampere University","correspondingAuthor":true,"prefix":"","firstName":"Elina","middleName":"","lastName":"Panula","suffix":""},{"id":601536243,"identity":"925f874a-089a-47a1-865d-49f5e62ac0b1","order_by":1,"name":"Pauli Vuorinen","email":"","orcid":"","institution":"Emergency Medical Services, Centre for Prehospital Emergency Care, Wellbeing Services County of Pirkanmaa, Tampere, Finland.","correspondingAuthor":false,"prefix":"","firstName":"Pauli","middleName":"","lastName":"Vuorinen","suffix":""},{"id":601536245,"identity":"8cb3264b-40df-43ff-94ff-599985892b63","order_by":2,"name":"Petri Aaltonen","email":"","orcid":"","institution":"Emergency Medical Services, Turku University Hospital and University of Turku, Wellbeing Services County of Southwest Finland.","correspondingAuthor":false,"prefix":"","firstName":"Petri","middleName":"","lastName":"Aaltonen","suffix":""},{"id":601536246,"identity":"f7b58987-c32b-434f-9e14-e3a4970c96c4","order_by":3,"name":"Riika Merivirta","email":"","orcid":"","institution":"Emergency Medical Services, Turku University Hospital and University of Turku, Wellbeing Services County of Southwest Finland.","correspondingAuthor":false,"prefix":"","firstName":"Riika","middleName":"","lastName":"Merivirta","suffix":""},{"id":601536247,"identity":"c197f21f-8647-40ee-8a35-aec277543b90","order_by":4,"name":"Mari Moilanen","email":"","orcid":"","institution":"Centre for Prehospital Emergency Care, Oulu University Hospital, Wellbeing Services County of Northern Ostrobothnia, Oulu, Finland.","correspondingAuthor":false,"prefix":"","firstName":"Mari","middleName":"","lastName":"Moilanen","suffix":""},{"id":601536249,"identity":"4932eebc-cd20-41bc-97b0-674c9c648402","order_by":5,"name":"Toni Pakkanen","email":"","orcid":"","institution":"Emergency Medical Services, Centre for Prehospital Emergency Care, Wellbeing Services County of Pirkanmaa, Tampere, Finland.","correspondingAuthor":false,"prefix":"","firstName":"Toni","middleName":"","lastName":"Pakkanen","suffix":""},{"id":601536250,"identity":"c6bc8d3e-9d9c-40ce-ae08-f80dcd8bd06b","order_by":6,"name":"Jari Pirnes","email":"","orcid":"","institution":"Emergency Medical Services, Wellbeing Services County of Lapland","correspondingAuthor":false,"prefix":"","firstName":"Jari","middleName":"","lastName":"Pirnes","suffix":""},{"id":601536254,"identity":"82b1e612-5b0d-4190-a3a0-b5e5c9bc187b","order_by":7,"name":"Jussi Pirneskoski","email":"","orcid":"","institution":"Emergency Medicine and Services, Helsinki University Hospital and University of Helsinki, Helsinki, Finland","correspondingAuthor":false,"prefix":"","firstName":"Jussi","middleName":"","lastName":"Pirneskoski","suffix":""},{"id":601536257,"identity":"6d37d40b-4028-4691-b969-5ce43d18cc15","order_by":8,"name":"Piritta Setälä","email":"","orcid":"","institution":"Emergency Medical Services, Centre for Prehospital Emergency Care, Wellbeing Services County of Pirkanmaa, Tampere, Finland.","correspondingAuthor":false,"prefix":"","firstName":"Piritta","middleName":"","lastName":"Setälä","suffix":""},{"id":601536261,"identity":"a1d1d4cd-f0eb-45f0-9282-bf072423b7c0","order_by":9,"name":"Pamela Toivonen","email":"","orcid":"","institution":"Centre for Prehospital Emergency Care, Kuopio University Hospital, Kuopio, Finland","correspondingAuthor":false,"prefix":"","firstName":"Pamela","middleName":"","lastName":"Toivonen","suffix":""},{"id":601536267,"identity":"f59d7905-889f-4a60-95d2-64030301c3f0","order_by":10,"name":"Heini Huhtala","email":"","orcid":"","institution":"Faculty of Social Sciences, Tampere University, Tampere, Finland","correspondingAuthor":false,"prefix":"","firstName":"Heini","middleName":"","lastName":"Huhtala","suffix":""},{"id":601536270,"identity":"272593ac-b36e-4894-9388-d8a019176d2e","order_by":11,"name":"Sami Länkimäki","email":"","orcid":"","institution":"Emergency Medical Services, Centre for Prehospital Emergency Care, Wellbeing Services County of Pirkanmaa, Tampere, Finland.","correspondingAuthor":false,"prefix":"","firstName":"Sami","middleName":"","lastName":"Länkimäki","suffix":""},{"id":601536272,"identity":"edd4e606-6640-48f1-b751-0b7b69ba3094","order_by":12,"name":"Sanna Hoppu","email":"","orcid":"","institution":"Emergency Medical Services, Centre for Prehospital Emergency Care, Wellbeing Services County of Pirkanmaa, Tampere, Finland.","correspondingAuthor":false,"prefix":"","firstName":"Sanna","middleName":"","lastName":"Hoppu","suffix":""}],"badges":[],"createdAt":"2026-02-23 10:53:38","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8946151/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8946151/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104258134,"identity":"834df262-9136-40e9-9500-56c99b3cb9dc","added_by":"auto","created_at":"2026-03-09 17:35:50","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":92737,"visible":true,"origin":"","legend":"\u003cp\u003eLocations of HEMS bases in Finland in 2024. Bases marked with an asterisk (*) are in university hospital cities.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8946151/v1/54ca491fd1a8d727f7826683.png"},{"id":104258135,"identity":"2d12ca51-2da2-4d43-a228-963c87a00ff0","added_by":"auto","created_at":"2026-03-09 17:35:50","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":103596,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart of patient inclusion\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8946151/v1/d57a3d0817faf04bf00bea0c.png"},{"id":105531072,"identity":"e21051da-3a25-490a-af34-03389ce8e3fc","added_by":"auto","created_at":"2026-03-27 05:56:48","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":750225,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8946151/v1/9f33b97a-1fbc-436c-b22c-c38e5b46ba0f.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Helicopter Emergency Medical Service transports in Finland in 2024: a national prospective observational study","fulltext":[{"header":"Background","content":"\u003cp\u003eHelicopter Emergency Medical Service (HEMS) has been an integral part of Finnish Emergency Medical Services (EMS) since 1992. Following organizational reforms in 2012, the Finnish Health Care Act has designated physician-staffed HEMS as a key component of EMS system with operational responsibility currently assigned to university hospitals within wellbeing services counties.\u003c/p\u003e \u003cp\u003eOver the past decade, the role of HEMS in Finland has evolved due to organizational changes and expanding clinical indications. In 2015, the Parliamentary Ombudsman of Finland noted that physician-staffed HEMS did not provide equal coverage for all emergency patients across the country. Ostrobothnia and Southeast Finland were identified as areas of greatest concern. It was also noted that, ongoing healthcare system reforms were likely to increase distances to emergency departments (ED).(\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e). These developments underscored the importance of HEMS in ensuring timely access to advanced prehospital care across geographically diverse regions.\u003c/p\u003e \u003cp\u003eIn 2020, HEMS units began transporting selected stroke patients with suspected large vessel occlusion to university hospitals for thrombectomy. Previously, Finnish physician-staffed HEMS were primarily dispatched to trauma cases, out-of-hospital cardiac arrests, and neurological emergencies other than stroke, while conscious stroke patients were not routinely considered candidates for HEMS activation (\u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe national HEMS network has also been extended with the establishment of the first rural physician-staffed HEMS unit, FinnHEMS40 (FH40), in 2022. This unit operates in an area characterized by long distances to tertiary care, illustrating the geographical variability of HEMS operational environments in Finland. In addition, the Finnish healthcare system underwent major structural reforms in 2023, further influencing the organization and delivery of EMS.\u003c/p\u003e \u003cp\u003eAgainst this background, contemporary national data on helicopter transports and patient characteristics within the Finnish HEMS system remain limited.\u003c/p\u003e \u003cp\u003eThe aims of this study were to 1) characterize the main patient groups and clinical features of patients transported by helicopters to university hospitals in Finland, 2) descriptively assess the potential time-saving of helicopter transport compared with estimated ground ambulance transport, and 3) describe operational characteristics of HEMS units, including FH40, within the national HEMS system.\u003c/p\u003e "},{"header":"Methods","content":"\u003cp\u003eStudy design\u003c/p\u003e\u003cp\u003eThis prospective, researcher-initiated, national observational cohort study collected data on all patients transported by helicopters to university hospitals in Finland during 2024. No interventions, medical treatments or invasive measurements were performed beyond the current emergency treatment protocol. Study protocol was approved by The Regional Ethics Committee of Tampere University Hospital (reference number ETL R23058/2023). The agreements required by law to conduct this study were completed with all wellbeing services counties and the joint authority HUS Group Area. This study is reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines.\u003c/p\u003e\u003cp\u003eSetting\u003c/p\u003e\u003cp\u003eFinnHEMS Ltd., a non-profit organization funded by the Finnish government, organizes HEMS in Finland. A physician, HEMS crew member (HCM) and a pilot form the crews of the six physician-staffed HEMS units. The seventh HEMS unit in Lapland (FH51) is staffed by two HCMs and two pilots. FH40 and FH51 illustrate the geographical variability of HEMS operational environments in Finland, particularly in areas with long distances to tertiary care.\u003c/p\u003e\u003cp\u003eFH40 provides an example of a physician-staffed HEMS unit operating outside a university hospital city in Finland. Its Euclidean distance to the nearest university hospital (Tampere University Hospital) is 142 kilometers. FH40 primarily transports patients to central hospitals, with further care provided, when necessary, at university hospitals (Oulu, Kuopio and Tampere).\u003c/p\u003e\u003cp\u003eMost HEMS physicians are specialists in anesthesiology and intensive care medicine and have completed an additional two-year education in prehospital emergency medicine; a small proportion are specialists in emergency medicine. HCMs are nurse paramedics or nurses with a bachelor’s degree in nursing and at least 30 European Credit Transfer System (ECTS) credits of additional training focused on advanced-level emergency care. HCMs are required to have a minimum of five years of work experience within EMS or an ED (\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eHEMS reaches approximately 80% of Finnish patients within 30 minutes of receiving an emergency phone call. Dispatchers working at six Emergency Response Centers (ERC) answer emergency calls from mainland Finland. Based on information received from the emergency call, ERC operators conduct a risk analysis that alerts appropriate authorities, including HEMS, to various emergency missions.\u003c/p\u003e\u003cp\u003eThe climate poses some limitations to helicopters in Finland. During winter, weather conditions often limit flying: during that time, HEMS crews operate short-range missions using rapid response vehicles with the same medical equipment as helicopters.\u003c/p\u003e\u003cp\u003eAlthough HEMS operations are nationally coordinated, individual units differ in terms of catchment area, operational profile, and clinical practices, reflecting geographical characteristics, population density, and regional healthcare structures.\u003c/p\u003e\u003cp\u003eParticipants\u003c/p\u003e\u003cp\u003eThis study cohort included all patients transported by helicopter. Of these, only patients with available informed consent were included in the 30-day follow-up analysis; other missing data were handled using complete-case analysis without imputation. Patients transported to central hospitals were excluded, as most helicopter-transported patients in Finland are transported to university hospitals. This restriction was applied to ensure comparability of transport pathways and follow-up.\u003c/p\u003e\u003cp\u003eAll patients and/or their next of kin were contacted by phone and were asked to provide informed consent to participate in this study. This study involved vulnerable groups and children under 16 years of age. In these cases, informed consent was requested from unconscious patients’ next of kin or, in case of children, from their parents, and when possible, from the children themselves. Separate information letters and consent forms were prepared for adult patients, adult patients’ next of kin, children under 7 years of age and children aged 7–15 years, and parents of children.\u003c/p\u003e\u003cp\u003eA data-secure electronic link containing all study information was sent via text or email to all potential participants, regardless of whether they could be reached by phone. Informed consent was obtained electronically, although some participants requested that the information and consent forms by postal mail. The forms were available in Finnish, Swedish and English. Participants and/or their next of kin retained the right to withdraw their participation at any time.\u003c/p\u003e\u003cp\u003eAs the study involved no interventions, a data permit was also obtained from the Wellbeing Services County of Pirkanmaa to access medical record information for a subset of patients transported by FH30 and FH40 in 2024. Exact numbers of all helicopter-transported patients in Finland in 2024 were obtained from FinnHEMS Ltd.\u003c/p\u003e\u003cp\u003eData collection\u003c/p\u003e\u003cp\u003ePatient information is routinely recorded in the FinnHEMS Database (FHDB) during and/or after patient transport in Finland (\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e). FHDB served as a template for a study-specific data collection form. Data collected included sex, age, time of the emergency call, indication of dispatch, HEMS time intervals, and treatment provided on scene and during transport.\u003c/p\u003e\u003cp\u003eComorbidities were assessed for patients in 30-day follow-up, and the Charlson Comorbidity Index (CCI) was calculated. CCI was used to describe baseline comorbidity burden and not intended as a measure of acute illness severity. CCI is a weighted index used to estimate one-year mortality risk based on comorbid conditions. Each comorbidity is assigned a weight from 1 to 6 based on its potential impact on mortality, and the total CCI score is calculated by summing these weights. Higher CCI scores indicate a greater burden of comorbidity.\u003c/p\u003e\u003cp\u003eAs ground ambulances did not transport these patients to hospital, ambulance transport times were not directly observed but estimated. Because exact scene addresses were unavailable, distances were calculated using Google Maps from the nearest township to the nearest university hospital. Estimated ambulance transporttimes were derived assuming an average driving speed of 95 kilometers per hour with lights and sirens.\u003c/p\u003e\u003cp\u003eData were collected using a secure data capture software, Research Electronic Data Capture (REDCap). All HEMS bases were provided with an electronic link, and Quick Response (QR) code to complete the study form.\u003c/p\u003e\u003cp\u003eData collection started on January 1st and ended on December 31st, 2024. Due to delays related to agreement issues, only three HEMS bases (FH30, FH40 and FH60) could begin data collection on January 1st. Others started between January 8th and March 18th (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003ePatient outcomes\u003c/p\u003e\u003cp\u003ePatient outcomes were followed for one month after helicopter transport if informed consent was obtained. Research physicians from each HEMS base entered patient information into a separate REDCap form regarding the hospital stay. This form included information about the length of the overall hospital stay, specifically the intensive care unit (ICU) stay, procedures performed on the patient during the hospital stay, and the neurological outcome at one month after helicopter transport.\u003c/p\u003e\u003cp\u003eNeurological outcome was assessed by the medical director of each HEMS unit using the electronic health record system and categorized according to the Cerebral Performance Category (CPC) score. CPC is a five-point scale commonly used to describe neurological outcomes after cardiac arrest, with scores 1– 2 considered good and 3–5 poor. CPC was used as pragmatic, generic measure of neurological outcome across heterogenous patient groups, as the predominant patient group was not known at the study outset.\u003c/p\u003e\u003cp\u003eWe also assessed the population-adjusted transport rates for each HEMS unit. Finland is divided into 19 administrative regions, and HEMS operational areas do not fully correspond to these regional boundaries, with some units covering overlapping or partial regions. Therefore, exact population figures for each HEMS unit´s catchment area were not available. Population estimates were based on regional statistics from Statistics Finland (\u003cspan class=\"CitationRef\"\u003e5\u003c/span\u003e) and estimated population numbers were used in the analysis.\u003c/p\u003e\u003cp\u003eStatistics\u003c/p\u003e\u003cp\u003eStatistical analyses were performed using IBM SPSS Statistics for Mac 30.0.0.0 (171) (IBM Corp. Armonk, NY, USA). Study populations were characterized using descriptive statistics. Transport times are presented as medians with interquartile ranges (IQR 25th – 75th percentiles). Group comparisons were performed using the Kruskal-Wallis test for continuous variables and Fisher´s exact test for categorical variables. A p-value \u0026lt; 0.05 was considered significant.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eAltogether, 604 patients were transported by helicopters to central and university hospitals in Finland in 2024. Of these, 516 patients (85%) were transported to university hospitals and constituted the primary study population. Complete transport data were available for 467 patients (90%).\u003c/p\u003e \u003cp\u003eFollow-up data at 30 days were available for 219 patients (47%). Of these, informed consent was obtained from 165 patients (35% of the primary study population) and/or their next of kin, an additional 54 patients were included based on data use agreement with the Wellbeing Services County of Pirkanmaa. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e illustrates the flow of patient inclusion.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eMost patients transported by helicopters were male (293 [63%]). The median age was 64 years (IQR 44\u0026ndash;73), with trauma patients having a median age of 43 years (IQR 21\u0026ndash;64) and stroke patients a median age of 69 years (IQR 60\u0026ndash;75). CCI was 0\u0026ndash;3 in most cases (171/220, 78%).\u003c/p\u003e \u003cp\u003eThe three most common indications for helicopter transports were 1) stroke (200, 43%), 2) trauma (137, 29%) and 3) neurological causes excluding stroke (45, 9.6%) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the indications of transports by helicopter and the number of patients transported to university hospitals by each HEMS unit. Among the three most common indications of helicopter transport, the proportion of patients transported for neurological conditions other than stroke varied across HEMS units (p\u0026thinsp;=\u0026thinsp;0.02). No difference was observed in transports due to trauma (p\u0026thinsp;=\u0026thinsp;0.09) or stroke (p\u0026thinsp;=\u0026thinsp;0.19).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eIndications of HEMS transports in Finland in 2024 (N\u0026thinsp;=\u0026thinsp;467)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIndication of HEMS transport\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e%\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStroke\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e43\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTrauma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e137\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e29\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNeurological (excluding stroke)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOHCA*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChest pain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntoxication/RDS**/infection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAortic catastrophe\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOther***\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCombined****\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003e*OHCA\u0026thinsp;=\u0026thinsp;out-of-hospital cardiac arrest\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003e** RDS\u0026thinsp;=\u0026thinsp;respiratory distress syndrome\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e*** Other includes rare indications (each n\u0026thinsp;\u0026le;\u0026thinsp;2), such as cardiac arrhythmia, anaphylaxis, snake bite, hypoglycemia, and postoperative complications.\u003c/p\u003e \u003cp\u003e**** Combined indicates missions with more than one primary indication.\u003c/p\u003e \u003cp\u003ePercentages are calculated from total N\u0026thinsp;=\u0026thinsp;467 unless otherwise stated.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMain indications for helicopter transport by HEMS unit\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"12\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eIndication\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003eHEMS unit\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c11\" namest=\"c10\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c12\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFH10\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;120)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFH20\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;37)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFH30\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;40)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFH40\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;65)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c8\" namest=\"c6\"\u003e \u003cp\u003eFH50\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;49)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c10\" namest=\"c9\"\u003e \u003cp\u003eFH51\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;39)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c12\" namest=\"c11\"\u003e \u003cp\u003eFH60\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;117)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStroke, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e49 (41)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10 (27)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17 (43)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e31 (48)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c8\" namest=\"c6\"\u003e \u003cp\u003e20 (41)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c10\" namest=\"c9\"\u003e \u003cp\u003e13 (36)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c12\" namest=\"c11\"\u003e \u003cp\u003e59 (50)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTrauma, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e37 (31)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12 (32)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9 (23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e24 (37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c8\" namest=\"c6\"\u003e \u003cp\u003e13 (27)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c10\" namest=\"c9\"\u003e \u003cp\u003e17 (44)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c12\" namest=\"c11\"\u003e \u003cp\u003e25 (21)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOther neurological, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7 (5.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (2.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3 (7.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2 (3.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c8\" namest=\"c6\"\u003e \u003cp\u003e4 (8.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c10\" namest=\"c9\"\u003e \u003cp\u003e4 (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c12\" namest=\"c11\"\u003e \u003cp\u003e20 (17)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOHCA*, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9 (7.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (2.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7 (18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c8\" namest=\"c6\"\u003e \u003cp\u003e4 (8.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c10\" namest=\"c9\"\u003e \u003cp\u003e1 (2.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c12\" namest=\"c11\"\u003e \u003cp\u003e5 (4.3)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOther, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18 (15)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13 (35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4 (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6 (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c8\" namest=\"c6\"\u003e \u003cp\u003e8 (16)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c10\" namest=\"c9\"\u003e \u003cp\u003e4 (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c12\" namest=\"c11\"\u003e \u003cp\u003e8 (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"12\"\u003e*Out of Hospital Cardiac Arrest\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eMost (262, 56%) of the patients were transported during the summer months (May \u0026ndash;August), while January (10, 2.1%), February (9, 1.9%), November (21, 4.5%) and December (23, 4.9%) had the fewest helicopter transports.\u003c/p\u003e \u003cp\u003eMedian transport times varied across HEMS units, with FH51 exhibiting the longest transport times. Units located in university hospital cities generally had shorter transport times. Estimated ground ambulance transport times are presented in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e for comparison.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMedian helicopter and estimated ambulance transport times by HEMS unit.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eFH unit\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHelicopter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAmbulance\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eΔ\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMedian (IQR)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMedian (IQR)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFH10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23 (18\u0026ndash;34)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e57 (36\u0026ndash;86)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e34\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFH20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19 (18\u0026ndash;24)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e47 (15\u0026ndash;59)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFH30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25 (22\u0026ndash;30)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e61 (50\u0026ndash;87)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e36\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFH40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e48 (41\u0026ndash;56)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e113 (107\u0026ndash;151)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e65\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFH50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e44 (35\u0026ndash;52)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e89 (70\u0026ndash;119)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFH51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e71 (55\u0026ndash;83)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e181 (140\u0026ndash;222)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e110\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFH60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31 (25\u0026ndash;36)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e79 (64\u0026ndash;100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e*FH=FinnHEMS\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eΔ\u0026thinsp;=\u0026thinsp;difference between median helicopter and estimated ambulance transport times\u003c/p\u003e \u003cp\u003eHelicopter transport times differed between HEMS units (Kruskal\u0026ndash;Wallis test, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Ground ambulance transport times are based on standardized estimates.\u003c/p\u003e \u003cp\u003ePopulation-adjusted transport rates varied between HEMS units, with generally higher rates observed in units operating in areas with longer distances to tertiary care and lower population density (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePopulation-adjusted number of helicopter transports by HEMS unit.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBase\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePopulation (N)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePatients transported (n)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePatients/100 000 population (n)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFH10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u0026nbsp;782\u0026nbsp;000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e120\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFH20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e495\u0026nbsp;000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFH30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e548\u0026nbsp;000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFH40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e440\u0026nbsp;000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFH50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e420\u0026nbsp;000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFH51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e176\u0026nbsp;000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFH60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e378\u0026nbsp;200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e117\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e31\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003ePatient treatment at the scene and 30-day follow-up\u003c/p\u003e \u003cp\u003eHEMS physicians did not perform any treatment procedures in most missions (318/467, 68%). Patient\u0026rsquo;s clinical condition remained unchanged or improved in 445 of 467 (95%) cases during transport.\u003c/p\u003e \u003cp\u003eAirway management was the most common on-scene intervention (113/467, 24%), most often involving endotracheal intubation (97/113, 86%). Other frequently performed procedures included the use of ultrasound (45/467, 9.6%) and spinal immobilization (35/467, 7.4%).\u003c/p\u003e \u003cp\u003eAmong patients requiring airway management, rocuronium was the most commonly used neuromuscular blocking agent 89/113 (79%) and was always combined with a sedative. The most frequently administered sedatives were fentanyl (79/113, 70%), S-ketamine (72/113, 64%) and propofol (35/113, 31%). In four (3.5%) cases, no prior medication was administered before intubation. Most intubated patients (70/97, 72%) received continuous propofol-infusion during transport.\u003c/p\u003e \u003cp\u003eRegarding hemodynamic management, the most frequent procedures among all patients were intravenous cannulation (207, 44%) and arterial cannulation (75, 16%). Noradrenaline was the most administered vasoactive agent (76, 16%). Blood products (red blood cells and lyophilized plasma) were given to 24 (5.1%) patients and one patient received low-titer type ORh+ whole blood because of ongoing whole blood research.\u003c/p\u003e \u003cp\u003eMost patients in 30-day follow-up (135/219, 61%), underwent computed tomography scan in ED. Interventional radiology procedures were conducted on 54 (25%) patients and surgical procedures on 37 (17%). In four (1.8%) cases, life-sustaining treatment was withdrawn in the ED. After hospital admission and the performed procedures, 96 (44%) of patients were managed in ICUs. The mean length of stay in the ICU was 4.9 [SD 5.9] days. Patients were mainly discharged to central hospitals (61, 28%) or home (48, 22%). For a one-month follow up-period, the mean length of overall stay at hospital(s) was 9.4 [SD 10] days.\u003c/p\u003e \u003cp\u003eMost of the follow-up patients (183, 84%), were alive after a month of helicopter transport, and the neurological outcome was good (CPC 1\u0026ndash;2) in most patients (132, 72%). Assistance with all daily activities (CPC 3) was needed by 47 (26%) of patients.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study was primarily descriptive and aimed to provide a contemporary national overview of helicopter transports to university hospitals in Finland. The findings offer insight into current patient characteristics, transport patterns, and operational features within the Finnish HEMS system.\u003c/p\u003e \u003cp\u003eCompared with earlier Finnish HEMS reports (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e), in which trauma constituted the most common patient group, stroke was the leading indication for helicopter transport in 2024. This change may indicate an ongoing shift in HEMS utilization toward time-critical neurological conditions, likely influenced by organizational reforms and updated dispatch practices.\u003c/p\u003e \u003cp\u003eThe predominance of male patients and the observed age distribution\u0026mdash;particularly the younger age of trauma patients and older age of stroke patients\u0026mdash;are consistent with previously established patterns in HEMS transport and illustrate the heterogeneity of clinical presentations encountered by HEMS units. The CCI was predominantly low, indicating that most helicopter-transported patients had limited comorbidity burden, which is consistent with the acute nature of conditions that typically require helicopter transport. Together, these findings characterize the contemporary profile of helicopter-transported patients within the Finnish HEMS system.\u003c/p\u003e \u003cp\u003eGeographic variation and transport times\u003c/p\u003e \u003cp\u003eTransport times by both helicopter and estimated ground ambulance increased with distance to tertiary care hospitals, reflecting geographical variation in access to advanced care across Finland. In areas with longer distances to university hospitals, HEMS units transported a higher proportion of patients by helicopter when adjusted for population size. This suggests that the utilization of helicopter transport is influenced by regional geography and accessibility rather than solely by patient-related factors. These findings highlight the role of HEMS in addressing geographical disparities in access to tertiary care, particularly in remote and sparsely populated regions.\u003c/p\u003e \u003cp\u003eRegional variation within the national HEMS system\u003c/p\u003e \u003cp\u003eSome Finnish HEMS units operate in geographically distinct environments characterized by long distances to tertiary care university hospitals. FH40, similar to FH51, serves a predominantly rural central hospital region where long transport distances are inherent to the operational setting. As a result, patients transported by FH40 had longer median transport times than those transported by HEMS units located in university hospital cities. However, these estimates should be interpreted cautiously, as HEMS operational areas do not fully correspond to administrative regions and population figures are therefore approximate.\u003c/p\u003e \u003cp\u003eWhen adjusted for population size, FH40 transported a relatively high number of patients by helicopter. Similar patterns were observed in other regions with longer distances to tertiary care, including FH51 and FH60, which operate in regions with varying population density and distances to tertiary care. These findings illustrate how regional factors, including distance to tertiary care, population density, and accessibility of university hospitals, influence HEMS mission profiles and transport patterns within the national system. Rather than representing a fundamentally different model of HEMS utilization, FH40 may illustrate how helicopter transport can mitigate geographical barriers to tertiary care in certain regions. However, FH40 should be interpreted as one example within the broader national HEMS system rather than as a distinct model of HEMS utilization.\u003c/p\u003e \u003cp\u003ePrehospital interventions and system-level role of HEMS\u003c/p\u003e \u003cp\u003eMost patients (67%) underwent no procedures during HEMS missions. In Finland, ground ambulance units often reach the patient before HEMS and may initiate initial treatment procedures prior to HEMS arrival, which may partly explain the relatively low number of procedures performed by HEMS physicians. This finding may also reflect the role of HEMS in facilitating rapid transport to tertiary care rather than providing extensive on-scene interventions. Overall, the observed pattern of prehospital interventions suggests that helicopter transport in Finland is frequently used as a logistical resource in time-critical situations, while advanced medical procedures are performed selectively when clinically indicated. The distribution and frequency of procedures were broadly consistent with national registry data (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eSurvival and outcomes\u003c/p\u003e \u003cp\u003eIn the present study, the median age of all helicopter-transported patients was 64 years, which is broadly comparable to previously reported mean ages of ICU patients in Finland (approximately 62 years) and patients treated by EMS (66 years) (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Among patients with available follow-up data, nearly half (44%) required ICU-level care, indicating that helicopter-transported patients represented a population with substantial acute care needs. The mean duration of ICU stay was 4.9 days in this study, whereas previous Finnish registry data have reported an average ICU stay of approximately 1.5 days (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). This likely reflects selection of more severely ill patients rather than an effect of helicopter transport.\u003c/p\u003e \u003cp\u003eMost patients with available follow-up data survived the first month after helicopter transport, and the majority demonstrated favorable neurological outcomes. However, these findings should be interpreted cautiously due to the limited follow-up rate and potential selection bias. The observational design of the study does not allow causal conclusions regarding the impact of helicopter transport on survival or neurological outcomes.\u003c/p\u003e \u003cp\u003ePrevious studies have suggested that HEMS transport may be associated with improved outcomes in selected patient populations, particularly when rapid access to tertiary care is critical (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). However, reported results are inconsistent and confounded by differences in patient severity, distance, and dispatch criteria. For example, a large Swedish registry study reported lower 30-day mortality among trauma patients transported by HEMS compared with ground ambulance, although neurological outcomes at discharge were less favorable among HEMS patients (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). These findings illustrate the complexity of interpreting outcome measures in heterogeneous prehospital populations and highlight the influence of confounding factors such as injury severity, distance to hospital, and selection bias.\u003c/p\u003e \u003cp\u003eThe question of which patient groups benefit most from physician-staffed HEMS or helicopter transport remains unresolved. Variability in HEMS systems, dispatch criteria, and staffing models across countries complicates direct comparisons and limits the generalizability of findings. Galvagno et al. (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e) have noted that, although results vary, improved survival is often observed in HEMS populations when analyses adjust for confounding factors such as severity and transport distance. Potential benefits are likely multifactorial, involving transport speed, crew expertise, and integration within regional trauma and stroke systems.\u003c/p\u003e \u003cp\u003eIn this study, only one patient with sepsis was identified, and no cases of septic shock or arrhythmia-related shock were observed, despite these conditions having been considered potential indications for rapid helicopter transport in Finnish prehospital practice. This observation raises questions about current dispatch patterns and the extent to which HEMS resources reach critically ill patient groups beyond trauma and stroke. Previous evidence from sepsis populations has shown that although helicopter transport may reduce transfer times, this does not necessarily translate into improved mortality or secondary outcomes (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e), underscoring the complexity of linking time savings to patient-centered outcomes.\u003c/p\u003e \u003cp\u003eStrengths and limitations\u003c/p\u003e \u003cp\u003eA key strength of this study is its prospective design, which enabled the collection of data on predefined clinical and operational variables. In addition, outcome data were obtained beyond routine registry information, allowing assessment of survival and neurological outcomes that would not have been available from the FHDB alone.\u003c/p\u003e \u003cp\u003eThis study has several limitations. First, only patients transported by helicopter to university hospitals were included. While this limits generalizability, it also enables more consistent follow-up within tertiary care settings. Although university hospital transports accounted for the majority of helicopter missions in Finland in 2024, the exclusion of central hospital transports may introduce selection bias, which should be taken into account when interpreting the findings.\u003c/p\u003e \u003cp\u003eSecond, ground ambulance transport times were estimated rather than directly measured, which introduces uncertainty in comparisons between transport modalities. In contrast, helicopter transport times were based on recorded mission data, providing accurate measurements for HEMS transports.\u003c/p\u003e \u003cp\u003eThird, follow-up data were incomplete, as informed consent was obtained for only a subset of patients. Although additional data access for two HEMS units increased the proportion of patients with 30-day outcome data, missing follow-up remains a potential source of bias and limits the interpretation of outcome findings.\u003c/p\u003e \u003cp\u003eFinally, patient data were entered manually, which may have led to occasional inaccuracies in data recording.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn 2024, stroke and trauma were the main indications for helicopter transport. Helicopter missions were generally faster than modelled ambulance transports. FH40 accounted for a substantial proportion of long-distance transports to tertiary care. Among patients with follow-up data, survival and neurological outcomes were favorable. Overall, the findings provide an updated national overview of helicopter transports and suggest that helicopter use may facilitate timely access to advanced care. Further studies are warranted to assess patient-centered outcomes.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCCI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCharlson Comorbidity Index\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCPC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCerebral Performance Category\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eECTS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEuropean Credit Transfer System\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eED\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEmergency Department\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eEMS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEmergency Medical Services\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eERC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEmergency Response Center\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFH\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eFinnHEMS\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFHDB\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eFinnHEMS Database\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eGDPR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eGeneral Data Protection Regulation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHCM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHEMS Crew Member\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHEMS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHelicopter Emergency Medical Services\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eICU\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eintensive care unit\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIFR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003einstrument flight rules\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIQR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003einterquartile range\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOHCA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eOut-of-Hospital Cardiac Arrest\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eRDS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003erespiratory distress syndrome\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSD\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003estandard deviation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eVFR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003evisual flight rules\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003eEthics approval and consent to participate\u003c/p\u003e\n\u003cp\u003eThe Regional Ethics Committee of Tampere University Hospital (ETL R23058) approved this study. All procedures were performed in accordance with the Declaration of Helsinki and its later amendments.\u003c/p\u003e\n\u003cp\u003eConsent for publication\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003eAvailability of data and materials\u003c/p\u003e\n\u003cp\u003eThe datasets generated and/or analyzed during the current study are not publicly available due to concerns that individual privacy could be compromised but are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003eCompeting interests\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003eFunding\u003c/p\u003e\n\u003cp\u003eThis study was financially supported by the Competitive State Research Financing of the Expert Responsibility Area of Tampere University Hospital (Grant No. 9AC011). The funding body had no role in the design, collection, analysis, interpretation of the data, or manuscript writing.\u003c/p\u003e\n\u003cp\u003eAuthors\u0026rsquo; contributions\u003c/p\u003e\n\u003cp\u003eEP: Conceptualization, Methodology, Investigation, Data curation, Formal analysis, Writing\u0026mdash;original draft. PV: Writing\u0026mdash;review and editing. PA: Data collecting, Writing\u0026mdash;review and editing. RM: Data collecting, Writing\u0026mdash;review and editing. MM: Data collecting, Writing\u0026mdash;review and editing. TP: Data collecting, Writing\u0026mdash;review and editing. JP: Data collecting, Writing\u0026mdash;review and editing. JPK: Data collecting, Writing\u0026mdash;review and editing. PS: Data collecting, Writing\u0026mdash;review and editing. PT: Data collecting, Writing\u0026mdash;review and editing. HH: Formal analysis, Writing\u0026mdash;review and editing. SL: Conceptualization, Methodology, Supervision, Writing\u0026mdash;review and editing. SH: Conceptualization, Methodology, Supervision, Writing\u0026mdash;review and editing. \u0026nbsp;All the authors have read previous versions of the manuscript and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003eAcknowledgements\u003c/p\u003e\n\u003cp\u003eWe express our deepest gratitude to all HEMS physicians working in FH10, FH20, FH30, FH40, FH50 and FH60 and nurse paramedics in FH51 for your participation in data collection in 2024. We would also like to express our sincere appreciation to Minna Ala-Karvia, the study coordinator, for her excellent assistance in preparing and launching this study, as well as her invaluable support in securing all necessary study approvals.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eMinistry of Social Affairs and Health. L\u0026auml;\u0026auml;k\u0026auml;rihelikopteritoiminta 2030-luvulle: esitys valtion l\u0026auml;\u0026auml;k\u0026auml;rihelikopteritoiminnan strategiaksi. Finland. 2023. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://urn.fi/URN:ISBN:978-952-00-4241-7\u003c/span\u003e\u003cspan address=\"https://urn.fi/URN:ISBN:978-952-00-4241-7\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. (accessed March 15, 2025).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSaviluoto A, Bj\u0026ouml;rkman J, Olkinuora A, Virkkunen I, Kirves H, Set\u0026auml;l\u0026auml; P, et al. The first seven years of nationally organized helicopter emergency medical services in Finland - the data from quality registry. Scand J Trauma Resusc Emerg Med. 2020;28(1):46. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/s13049-020-00739-4\u003c/span\u003e\u003cspan address=\"10.1186/s13049-020-00739-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFinnHEMS Ltd. Haemme ensihoitajia l\u0026auml;\u0026auml;k\u0026auml;rihelikopteriin. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://finnhems.fi/ajankohtaista/haemme-ensihoitajia-laakarihelikopteriin/\u003c/span\u003e\u003cspan address=\"https://finnhems.fi/ajankohtaista/haemme-ensihoitajia-laakarihelikopteriin/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed Jul 21, 2025).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHeino A, Iirola T, Raatiniemi L, Nurmi J, Olkinuora A, Laukkanen-Nevala P, et al. The reliability and accuracy of operational system data in a nationwide helicopter emergency medical services mission database. BMC Emerg Med. 2019;19(1). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/S12873-019-0265-Y\u003c/span\u003e\u003cspan address=\"10.1186/S12873-019-0265-Y\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStatistics Finland. Population and society. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://stat.fi/tup/suoluk/suoluk_vaesto.html#vaestotietoja-maakunnittain\u003c/span\u003e\u003cspan address=\"https://stat.fi/tup/suoluk/suoluk_vaesto.html#vaestotietoja-maakunnittain\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (accessed November 23, 2025).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eReinikainen M, Uusaro A, Niskanen M, Ruokonen E. Intensive care of the elderly in Finland. Acta Anaesthesiol Scand. 2007;51(5):522\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1111/J.1399-6576.2007.01274.X\u003c/span\u003e\u003cspan address=\"10.1111/J.1399-6576.2007.01274.X\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAitavaara-Anttila M, Liisanantti J, Ehrola A, Spalding M, Ala-Kokko T, Raatiniemi L. Use of prehospital emergency medical services according to income of residential area. Emerg Med J. 2020;37(7):429\u0026ndash;33. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1136/EMERMED-2019-208834\u003c/span\u003e\u003cspan address=\"10.1136/EMERMED-2019-208834\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJ\u0026auml;ntti S, Ponkilainen V, Kuitunen I, Uimonen MM, Huttunen T, Mattila VM. Intensive care unit admissions with and without COVID-19 in Finland from 2017 to 2021: a retrospective register-based study. BMC Anesthesiol. 2023;23(1):1\u0026ndash;7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/S12871-023-02207-9/TABLES/2\u003c/span\u003e\u003cspan address=\"10.1186/S12871-023-02207-9/TABLES/2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAckermann A, Pappinen J, Nurmi J, Nordquist H, Saviluoto A, Mannila S, et al. A scenario based approach to optimizing cost-effectiveness of physician-staffed Helicopter Emergency Medical Services compared to ground-based Emergency Medical Services in Finland. Scand J Trauma Resusc Emerg Med. 2024;32(1):60. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/S13049-024-01231-Z/TABLES/2\u003c/span\u003e\u003cspan address=\"10.1186/S13049-024-01231-Z/TABLES/2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLavery MD, Aulakh A, Christian MD. Benefits of targeted deployment of physician-led interprofessional pre-hospital teams on the care of critically Ill and injured patients: a systematic review and meta-analysis. Scand J Trauma Resusc Emerg Med. 2025;33(1). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/S13049-024-01298-8\u003c/span\u003e\u003cspan address=\"10.1186/S13049-024-01298-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLapidus O, Rubenson Wahlin R, B\u0026auml;ckstr\u0026ouml;m D. Trauma patient transport to hospital using helicopter emergency medical services or road ambulance in Sweden: a comparison of survival and prehospital time intervals. Scand J Trauma Resusc Emerg Med. 2023;31(1). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/S13049-023-01168-9\u003c/span\u003e\u003cspan address=\"10.1186/S13049-023-01168-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGalvagno SM. Comparative effectiveness of helicopter emergency medical services compared to ground emergency medical services. Crit Care. 2013;17(4). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/CC12779\u003c/span\u003e\u003cspan address=\"10.1186/CC12779\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKashyap R, Anderson PW, Vakil A, Russi CS, Cartin-Ceba R. A retrospective comparison of helicopter transport versus ground transport in patients with severe sepsis and septic shock. Int J Emerg Med. 2016;9(1). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/S12245-016-0115-6\u003c/span\u003e\u003cspan address=\"10.1186/S12245-016-0115-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"HEMS, Finland, transport, helicopter, ambulance","lastPublishedDoi":"10.21203/rs.3.rs-8946151/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8946151/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBackground\u003c/p\u003e\n\u003cp\u003eHelicopter Emergency Medical Service (HEMS) has been a key component of Finnish Emergency Medical Service since 2012. In recent years, the role of HEMS has evolved due to organizational changes and expanding indications for helicopter transport. In addition, the national HEMS network was extended with the establishment of the first rural physician-staffed HEMS unit, FinnHEMS40 (FH40), in 2022.\u003c/p\u003e\n\u003cp\u003eThe aims of this study were to characterize patient groups and clinical features of patients transported by helicopter to university hospitals in Finland, assess the potential time–saving of helicopter transport compared with estimated ground ambulance transport, and describe operational characteristics of FH40 within the national HEMS system.\u003c/p\u003e\n\u003cp\u003eMethods\u003c/p\u003e\n\u003cp\u003eThis prospective, observational study was conducted in Finland in 2024. All patients transported by helicopter to university hospitals were included. Primary outcomes were patient characteristics and operational metrics; 30-day survival and neurological outcome were assessed descriptively when available. HEMS physicians recorded patient and mission data using a secure electronic data capture system. Helicopter transport times were recorded, whereas ambulance transport times were estimated. Group comparisons were performed using the Kruskal-Wallis test for continuous variables and Fisher´s exact test for categorical variables.\u003c/p\u003e\n\u003cp\u003eResults\u003c/p\u003e\n\u003cp\u003eIn total, 467 of 513 patients (90%) transported by helicopters in 2024 were reported. Most patients were male (293, 63%) and the median age was 64 years (interquartile range (IQR) 44–73). The most common indications for helicopter transport were stroke (200, 43%) and trauma (134, 29%). Helicopter transport times were generally shorter than modelled ambulance transport times. Data for 219 (47%) patients were available at the 30-day follow-up, of whom 183 (84%) were alive. Among survivors, 132 (72%) had a good neurological outcome (Cerebral Performance Category 1–2).\u003c/p\u003e\n\u003cp\u003eConclusions\u003c/p\u003e\n\u003cp\u003eIn 2024, stroke and trauma were the main indications for helicopter transport. Helicopter missions were generally faster than modelled ambulance transports. FH40 accounted for a substantial proportion of long-distance transports to tertiary care. Among patients with follow-up data, survival and neurological outcomes were favorable. Overall, the findings provide an updated national overview of helicopter transports and suggest that helicopter use may facilitate timely access to advanced care, warranting further study of patient-centered outcomes.\u003c/p\u003e","manuscriptTitle":"Helicopter Emergency Medical Service transports in Finland in 2024: a national prospective observational study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-09 17:35:34","doi":"10.21203/rs.3.rs-8946151/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"7a1de1ee-60c8-4bc0-aa01-93c418109609","owner":[],"postedDate":"March 9th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-27T05:56:10+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-09 17:35:34","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8946151","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8946151","identity":"rs-8946151","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}