Introducing self-sampling for cervical cancer screening: A regional implementation study in Pirkanmaa, Finland.

Saara Kyllönen: Conceptualization, Data curation, Formal analysis, Investigation, Visualization, Writing—original draft. Satu Saloranta: Conceptualization, Investigation, Methodology, Data curation, Validation, Writing—review & editing. Saara Kares: Conceptualization, Investigation, Methodology, Data curation, Validation, Writing—review & editing. Anu Mustila : Conceptualization, Resources, Software, Validation, Writing—review & editing. Karolina Louvanto: Conceptualization, Data curation, Funding acquisition, Investigation, Methodology, Project administration, Resources, Software, Supervision, Validation, Visualization, Writing—review & editing.

The ethical statement for the study was approved by the Wellbeing County of Pirkanmaa District Ethical Review Board ELT R23093 /2024 January 16, 2024 ( NCT06931184 ).

This study was funded by Sigrid Juselius Foundation (KL), Syöpäsäätiö (Cancer Foundation Finland) (KL), State funding for University‐level Health Research, Tampere University Hospital, Wellbeing Services County of Pirkanmaa (KL), and Roche Diagnostics (KL).

Planning and setup for the FALCON study began in the fall of 2023, launching a demanding and carefully coordinated preparatory phase. Significant time and effort were invested in modifying IT systems to allow women to electronically opt‐in and order self‐sampling kits, an entirely new process for the region. In parallel, logistical pathways for distributing invitation letters and managing returned kits were designed and optimized. By spring 2024, the laboratory was fully prepared, and self‐sampling kits underwent thorough testing via the postal system to ensure reliability. Only after this extensive groundwork was completed were the first screening invitations sent out in February, followed by reminder letters including the FALCON self‐sampling option in late April 2024, marking the full operational launch of the study. Out of the 26 929 women who were initially invited for cervical cancer screening, a reminder letter with an invitation to participate in a self‐sampling study was sent to 60.5% ( n  = 16 289) of the women (Figure  1 ). Of these, 329 women ordered the self‐sampling kit and completed the first questionnaire, and 304 (92.4%) returned the kit. The 25 women who ordered the kit but did not return it ultimately did not participate in the invited screening. Flowchart of the 2024 cervical cancer screening process in Tampere and surrounding municipalities, including the initiation of the FALCON self‐sampling study. a Municipalities of: Tampere, Nokia, Ylöjärvi, Kangasala, Sastamala, Lempäälä, Pirkkala, Valkeakoski, Akaa, Hämeenkyrö, Orivesi, Mänttä‐Vilppula, Ikaalinen, Pälkäne, Parkano, Virrat, Ruovesi, Urjala, Vesilahti, Punkalaidun, Kihniö, Kuhmoinen, Juupajoki. b Participants who book the time or attend the screening after the second invitation letter is sent. The overall screening coverage in 2024 in Pirkanmaa was 70.1% (Table  1 ), of which 39.5% participated already after the first invitation and 29.5% after the second invitation. Among women aged 50 and older, participation was significantly higher after the first invitation than after the second. This trend was more pronounced with increasing age. Specifically, first‐round participation rates among women aged 50 and older ranged from 41.5% to 49.7%, while second‐round rates were much lower, at 20.1% to 30.2% ( p  < 0,0001). In contrast, women 45 and younger showed similar participation rates between the two invitations. Among women aged 50 and older, participation after the first invitation was 46.2% and among women 45 and younger, 33.5% ( p  < 0,0001). The lowest relative participation was observed among the youngest age groups (30 and 35 years old), with rates of 63.0% and 67.7%, respectively. When it came to self‐sampling, it was most common among women 65 and older, with a participation rate of 3.2%. For all other age groups, the self‐sampling rate was between 1.4% and 2.3%. Distribution of participants by screening invitation age in the Finnish national cervical cancer screening program and FALCON self‐sampling study in the Tampere region and surrounding municipalities in 2024. Sent to all non‐responders 8 weeks after the initial screening invitation was sent. Participants that book the time or attend screening after the second invitation letter was sent. Self‐sampling was exclusively offered to non‐responders within the second invitation mailing; therefore, this percentage reflects self‐sampling uptake specifically among participants in the second round of invitation. Participation in the first round compared to the second round. A summary of the background information collected from the questionnaire filled out by women who ordered a self‐sampling kit is presented in Table  2 . The participants' mean age was 48.0 (range 29.9–65.8) years. Women taking part in the study were more likely to be married or cohabiting (61.4%) and held a university or polytechnic degree (53.2%). Approximately two out of three reported having a chronic disease. The most reported conditions were thyroid disease, allergies, atopy, asthma and cardiovascular diseases. In terms of lifestyle factors, 14.9% of the participants reported being smokers. More than half of the women had experienced at least one delivery. Regarding menstrual health, 35% reported that menopause was the reason for the absence of menstruation, and 8.5% had a history of hysterectomy. A significant majority of participants (85.8%) had a history of previous screening, having undergone either a cervical cytology or an HPV test. Background information of the 329 women who took part to the FALCON self‐sample study. General upper secondary education and vocational education. Sleep apnea, vulvodynia, inflammatory bowel disease, malignant disease, liver disease, renal disease. The main reason for choosing self‐sampling was to save time (Table  3 ). About three out of four said that the quickness of the process influenced their willingness to choose self‐sampling. Additionally, 55.6% of women chose self‐sampling because laboratory sampling was unpleasant or painful. Over half of the women reported the previous experience as unpleasant regarding gynecological examinations or sampling. Furthermore, 26.4% of the women thought that laboratory sampling was embarrassing. Interestingly, factors such as the affordability of sampling, limited laboratory appointments, or long travel distances had a minimal impact on the majority of the choice to use a self‐sampling kit. Besides convenience, participants gave a range of other reasons for choosing self‐sampling. Some women worked in laboratories and preferred not to have a coworker take their sample. A few women opted for self‐sampling to avoid having a male nurse perform the procedure. Other reasons included irregular menstruation, physical disability, and pregnancy, which made at‐home sampling more practical and comfortable. Two participants were pregnant, and one specifically chose self‐sampling due to her pregnancy. Additionally, many women chose self‐sampling simply to try a new method and support the study. Reported reasons and influencing factors for choosing self‐sampling among the 329 that took part in the FALCON study in 2024. The majority (90.5%) of self‐samples were HPV negative, and only 21 (6.9%) tested HPV positive (Table  4 ). HPV16 or 18 were detected in six self‐samples, while the remaining 15 were other hrHPV types. Eight (2.6%) self‐samples were deemed inadequate for analysis due to insufficient cellular material, resulting in DNA levels below the threshold required for interpretation. When a second self‐sample was requested due to an uninterpretable result, five of these were negative, one remained uninterpretable, and two were never returned by the participants. The most common reason for an invalid sample was ‘missing sample’, meaning that the tube had been sent back without a collected specimen. Following a positive self‐sample result, 18 women were referred to the laboratory. Of these, six had a negative result on their follow‐up laboratory sample. Among the 10 participants who remained HPV‐positive at the laboratory, cervical cytology was NILM for all but two: one participant had ASC‐US, and one had LSIL. The woman with LSIL cytology was later, in colposcopy, found to have a histological high‐grade squamous intraepithelial lesion (HSIL) and underwent excisional treatment with loop electrosurgical excision procedure (LEEP). Results of HPV testing, a cytology, and histology among self‐sampling participants. All HPV‐positive women were re‐tested for HPV‐testing when cervical cytology was collected. Those that were HPV positive on their self‐sample were all invited for laboratory testing of HPV and cervical cytology. Previous self‐sample were: 1 HPV type 16, 1 HPV type 18, and 4 other HPV types. Two months after the initial questionnaire, a second survey was completed by 260 to evaluate their self‐sampling experience (Table  5 ). The results showed a high level of satisfaction and confidence in the method. Most participants agreed that the instructions were clear, the sample was easy to collect, and they performed the procedure correctly. The majority found self‐sampling to be more comfortable than a laboratory‐collected sample and would recommend it to others. Only a small number of women reported the procedure as being painful (9.6%) or uncomfortable (14.6%). Most participants (56.9%) considered self‐sampling a reliable screening method, while 41.1% were neutral on the matter and 1.2% disagreed. Nearly all participants believed that self‐sampling would increase participation in screening programs. Acceptability and experience of self‐sampling among participants ( n  = 260).

The FALCON study represents the first evaluation of self‐sampling implementation within routine cervical cancer screening in Finland. Although the initial participation numbers were modest and do not yet allow firm conclusions about its impact on screening uptake, the study provides early evidence of high acceptability and practical feasibility of self‐sampling among women in Pirkanmaa, underscoring the need for larger‐scale evaluation. Cervical cancer screening attendance in the Pirkanmaa region in 2024 was 70.1%, which remained roughly consistent with previous years ( Finnish cancer registry ). Attendance rates appear comparable to those in other Nordic countries, such as Norway and Denmark. 11 , 21 The introduction of the self‐sampling option in reminder invitations did not increase screening coverage during the first year, similar to findings from the Netherlands, where self‐sampling has been available the longest. 18 In our study, only 1.9% of women who received a reminder letter opted for self‐sampling. The FALCON study employed an opt‐in design, requiring women to actively order a self‐sampling kit. While meta‐analyses report participation rates between 1.5% and 17.5% in opt‐in settings, our observed uptake of 1.9% is at the lower end of this range and substantially below the rates reported in the majority of published implementation studies. 20 This disparity highlights the significant challenges of translating the efficacy observed in controlled research settings into a real‐world, routine screening environment during an initial rollout year. A send‐to‐all approach, where every invitee receives a self‐sampling kit, has been shown to increase attendance, as demonstrated in the Helsinki study. 19 However, such an approach may reduce cost‐effectiveness if return rates are low. 19 , 20 Interestingly, a meta‐analysis showed that screening participation was higher among women invited for self‐sampling compared to controls, regardless of the invitation strategy. 20 One possible explanation for the low participation is that, in our study, self‐sampling was offered as a secondary option and research project in the invitation letter, following the traditional clinician‐collected method. This may have led women to perceive the conventional method as more reliable. Indeed, the information materials may have been suboptimal in addressing potential concerns regarding the analytical reliability of self‐sampling, which likely reinforced a preference for the established clinical procedure. Another contributing factor could be the design of the reminder letter. The invitation to participate in self‐sampling was printed on plain white paper with black text and placed after the standard instructions for booking a laboratory appointment, which may have failed to capture recipients' attention (Invitation letter provided as Supplementary Material). It is likely that many women either overlooked the self‐sampling option or did not open the reminder letter at all, having already read the initial invitation and booked their appointment accordingly. Furthermore, the demographic profile of those who did participate suggests a significant educational bias, as shown in Table  2 . This overrepresentation of women with higher education, often referred to as a “healthy user bias,” indicates that the current implementation model and invitation materials may not have effectively reached or resonated with a representative cross‐section of the non‐attender population. Our primary aim was to increase participation among the youngest age group, particularly women aged 30, where screening coverage is typically lowest. However, participation in this group remained low in 2024, and our data do not demonstrate the intended improvement for this demographic. Clearly, there is a need to identify new strategies to make screening participation easier for younger women. A recent Danish randomized study showed that participation among women under 50 years increased when the HPV self‐sample kit was directly mailed rather than offered via opt‐in. 29 Our findings similarly suggest that the opt‐in strategy may be less effective for younger women. Busy life stages involving pregnancy, young children, and work responsibilities may further limit participation. Clearer communication and more prominent invitations could make self‐sampling more appealing to this group. Interestingly, in contrast, the highest self‐sampling uptake in our study was among women aged 65. Mobility challenges, difficulty attending laboratory appointments, and discomfort with clinician‐collected samples, particularly due to postmenopausal vaginal dryness, likely contributed to the greater acceptance of self‐sampling in this age group. Similar findings of higher participation among older women have also been reported in previous self‐sampling studies, suggesting a clear benefit in offering this option to older cohorts who may face greater barriers to traditional screening. 29 , 30 Beyond age‐related factors, the socio‐economic profile of our participants also played a critical role. Our intention in offering self‐sampling was to reach women who do not typically participate in screening and who may belong to more vulnerable or underserved groups; however, our results suggest we did not fully achieve this objective. Participants in our cohort were predominantly highly educated, holding a university or polytechnic degree, had previous screening experience, and were more likely to be married or cohabiting. These findings align with the determinants identified by Harder et al., who found that lower educational attainment, low income, and being unmarried were significant barriers to self‐sampling uptake among non‐attenders. 31 The similarity between our results and these established determinants suggests that even when a low‐threshold option like self‐sampling is provided, socio‐economic barriers continue to disproportionately affect participation among the most underserved populations. HPV prevalence in self‐samples was comparable to rates typically observed in routine cervical cancer screening (Finnish Cancer Registry). In other studies, an average 0.7% of self‐samples have been unsatisfactory for hrHPV testing. 8 In our study, 2.6% of the self‐samples were initially uninterpretable, but after re‐sampling, only one remained unsatisfactory. This likely reflects challenges in collecting the sample correctly at home, possibly resulting in insufficient cellular material on the first attempt. The cost‐effectiveness of self‐sampling depends largely on uptake. If participation remains low, the substantial investments required, such as major IT modifications and logistical preparations, are unlikely to be cost‐effective. Based on our findings, we cannot conclude that the integration of self‐sampling into the 2024 screening program was cost‐effective, particularly as formal economic evaluations were not performed. The dry swab design used in our study has previously been shown to be cost‐effective, easy to transport, and suitable for room temperature storage, while maintaining comparable reliability to clinician‐collected samples. 32 , 33 Interestingly, 33% of women who were retested during cytology collection were already HPV negative. This may be explained by natural HPV clearance occurring between the two sampling time points. However, other factors could also contribute, such as transient or low‐level infections falling below detection thresholds, sampling variability between home and clinician collection, or initial false‐positive results from transient contamination. Convenience was the main reason women chose self‐sampling, with many also citing discomfort or embarrassment with clinician‐collected samples, findings consistent with earlier studies showing self‐sampling to be less painful and stigmatizing compared to clinician‐collected sampling. 22 Nearly all participants found home sampling easy and instructions clear, reflecting its high acceptability, as reported also elsewhere. 22 , 23 , 24 Self‐sampling also offers an important alternative for women who avoid traditional screening due to physical limitations or previous negative experiences. However, some remain hesitant due to concerns about reliability, a perception noted in previous research. 22 Clear communication about the validity of self‐sampling and its proven reliability is therefore crucial to increasing confidence, improving uptake, and ensuring broader participation in cervical cancer screening programs. A key strength of this study is its implementation within the routine cervical cancer screening program, ensuring that the reminder letters and self‐sampling offer were delivered uniformly to all eligible women. The large invitation cohort strengthens the generalizability of the findings, even though participation during the initial year was low. However, the study also has important limitations. The relatively small number of self‐sampling participants in this first year restricts the ability to draw firm conclusions about its impact on screening coverage. Furthermore, the demographic profile of the participants revealed a significant educational bias; women with higher education were overrepresented, which may limit the generalizability of our findings to the broader, more diverse population of non‐attenders. We were also unable to determine why some women who ordered self‐sampling kits did not return them, whether due to difficulties in sample collection, lack of time, or dissatisfaction with the method. Finally, all study materials were provided only in Finnish, which may have reduced accessibility for non‐native speakers and contributed to lower participation in some subgroups.

The FALCON study provides compelling initial evidence that self‐sampling is both highly acceptable and practically feasible in Pirkanmaa, Finland. However, in this initiation phase, high individual acceptability did not translate into improved overall screening coverage. Future work must focus on optimizing invitation methods and wider implementation to fully assess its impact on overall cervical cancer screening coverage, improve equity, and realize the method's potential for program efficiency.

Human papillomavirus (HPV) primary testing is currently the first choice of cervical cancer screening method worldwide with reflex cervical cytology for those who test high‐risk (hr) HPV‐positive. 1 , 2 HrHPV‐DNA primary testing has opened the opportunity of vaginal self‐sampling to increase screening attendance. The PCR‐based HPV self‐sample tests have been tested to have equal screening performance compared to provider‐obtained samples. 3 , 4 , 5 , 6 , 7 Systematic reviews and meta‐analyses show that offering screening non‐attenders hrHPV self‐sampling can significantly increase attendance and the detection of high‐grade disease. 8 , 9 , 10 , 11 Additionally, the WHO recommends HPV cervical self‐sampling as a screening method for women aged ≥30 years. 12 Self‐sampling for cervical cancer screening is currently used in national or regional programs in countries including the Netherlands, Australia, Denmark, Sweden, and several countries in Latin America, Asia, and Africa. 3 , 13 , 14 , 15 , 16 , 17 Implementation varies: some countries offer self‐sampling as a primary option, while others target under‐screened populations. The Netherlands was the first country to introduce self‐sampling in 2017 into the screening program. 15 Although the screening coverage has not increased, the proportion of women choosing self‐collection did, from around 7% when it was first introduced, increasing to 44% in 2023. 17 , 18 Different methods of inviting women for HPV self‐sampling have been applied. Send‐to‐all self‐sampling, where every invitee receives the sampling package together with the invitation, has been shown to increase screening attendance among non‐attendees, although return rates may vary, potentially reducing cost‐effectiveness. 19 , 20 Opt‐in self‐sampling has also proven to be both successful and cost‐effective, where the invitation is sent first, and the woman actively chooses to order a sampling kit. 3 , 11 , 21 In an updated meta‐analysis, participation in self‐sampling studies varied 1.5–17.5% in the opt‐in setting and 6.4–34% in the mail‐to‐all setting. 20 In Norway and Denmark, 17% of cervical cancer screening non‐attendees returned the HPV self‐sample for analysis in an opt‐in research setting. 11 , 21 Self‐sampling has also been shown to be an acceptable method for cervical cancer screening. 22 , 23 , 24 Self‐sampling is considered a preferred choice for screening and is less painful compared to clinician sampling. 15 , 22 , 23 However, among participants, clinician or laboratory‐based sampling has been considered more reliable, as some individuals express concern about performing the self‐sample procedure incorrectly. 15 , 22 , 23 In Finland, an organized population‐based cervical cancer screening program was established already in the early 1960s and has reduced the incidence and mortality of cervical cancer by 80% from the baseline. 25 However, in recent years, cervical cancer incidence has concerningly increased by approximately 12%, especially among the screening non‐attendees, who are often young women of childbearing age ( Finnish Cancer registry ). So far, self‐sampling has been tested in only a research setting in the capital city region of Helsinki in Finland, where self‐sampling increased the cervical cancer screening participation rate from 70% to over 80% when self‐sampling was used as a second or third intervention with reminder letters. 19 , 26 , 27 Although those results were encouraging, self‐sampling is not yet included in standard screening protocols across Finland. Consequently, there is a critical need to gather implementation data from other major urban and semi‐urban regions, such as Pirkanmaa, to assess the broader scalability of the model.

Roche Diagnostics provided a small grant and supplied part of the materials for this study. The company had no role in the study design, data collection, analysis, or interpretation, nor in the decision to publish the results (KL). The other authors declare no conflict of interest.

Pirkanmaa's routine cervical cancer screening program, along with those of surrounding municipalities, is coordinated by Fimlab Laboratories Ltd., a publicly owned service provider in Finland. All women aged 30–65 years are invited to attend screening at 5‐year intervals. Screening samples are taken by trained nursing staff at primary health care facilities of Fimlab Laboratories. Women with negative hrHPV test results are considered screening‐negative and are invited for the next routine screening after 5 years, while those testing hrHPV positive are triaged with cervical cytology. Women with low‐grade squamous intraepithelial lesion or worse (LSIL+) are referred to colposcopy, whereas those with atypical squamous cells of undetermined significance (ASC‐US) or negative for intraepithelial lesion or malignancy (NILM) are scheduled for re‐testing in 12–24 months. If hrHPV positivity persists at re‐testing, colposcopy is recommended regardless of cytology findings. 28 The self‐sampling in cervical cancer routine screening (FALCON) study included women who did not respond to the first screening invitation and to whom the reminder letter was sent. In the reminder letter (Supplementary material) women were informed of the possibility of taking part in the self‐sampling study instead of booking a time at the laboratory. Only women belonging to the invited birth cohorts of the regional screening program were included in the study. Due to the study materials being available only in Finnish, individuals who did not speak or understand Finnish were excluded. The study followed an opt‐in design: women who wished to participate read the study information, signed the consent via her id secured electronical Suomi.fi account and then ordered a self‐sampling kit and completed a brief questionnaire. The questionnaire collected basic demographic information and reasons for choosing self‐sampling. The self‐sampling kit included the FLOQSwab (Copan), instructions, and a pre‐paid return envelope addressed to Fimlab Laboratories. Samples were mailed as dry samples back to the laboratory. The estimated return mail took approximately 2–5 business days. Women who tested positive for hrHPV in their self‐sample received a letter instructing them to book an appointment for cervical cytology in 1 month, when also a repeat hrHPV test was collected. If the laboratory HPV test was negative, the participant was considered screening‐negative and referred to the next routine screening in 5 years. If the test was recoded as invalid, it was re‐analyzed, and if the result was still invalid a second time as well, a new sampling kit was sent to the customer. If that result also came back negative or the sample was not returned, the customer was contacted and asked to visit a laboratory for sample collection. HPV‐positive women who did not book an appointment for cytology after the first reminder letter were sent a second reminder to book the appointment. This letter also included a reminder that if they did not schedule the appointment, they would be responsible for managing the follow‐up of their positive HPV result themselves. All follow‐up procedures of re‐testing and colposcopy referrals adhered to the current Finnish national care guidelines. Two months after ordering the self‐sample kit, FALCON study participants were invited to complete a follow‐up survey regarding their experiences with self‐sampling. A 2‐month interval was designated to ensure that participants had sufficient time to receive the kit, perform the collection, return the sample, and receive their screening results prior to evaluating the process. The data for this study were gathered from the Fimlab laboratory and Tampere University Hospital patient charts. This study was approved by the Pirkanmaa Hospital District Ethical Review Board ( R23093 /2024), with registered at ClinicalTrials.gov ( NCT06931184 ). After the self‐collected samples were received, the dry sample was first diluted in the Roche Cell Collection Medium. The time from collection to dilution was approximately 7–10 days. HPV genotyping was performed at Fimlab laboratories using the Roche Cobas 4800 HPV assay, which identifies hrHPV types 16 and 18 separately and the other 12 high‐risk HPV types together (31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68). Cervical cytological samples were graded according to the Bethesda System (TBS). Data on screening invitations and participation in both traditional screening and self‐sampling by age groups were obtained from Fimlab databases. Participation rates between age groups were compared using the chi‐squared test. Descriptive statistics were applied to evaluate background characteristics. Women's reasons for choosing the self‐sample option were assessed using eight structured questions with space for open‐ended responses. Answers were summarized into three categories: strong impact (affected quite a lot or very much), neutral, and minimal impact (did not affect at all or affected very little). Acceptability and user experience were assessed with nine Likert‐scale questions (five response options scoring from 1 to 5). Responses collapsed into three categories: agree (somewhat or strongly agree), neutral, and disagree (somewhat or strongly disagree). Continuous variables were summarized using means and standard deviations. Statistical analyses were performed using Stata 19 (StataCorp, TX).

Data S1.