Reducing oral broad-spectrum antibiotics use at an outpatient setting: an antimicrobial stewardship project

Reducing oral broad-spectrum antibiotics use at an outpatient setting: an antimicrobial stewardship project | 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 Short Report Reducing oral broad-spectrum antibiotics use at an outpatient setting: an antimicrobial stewardship project Khin Zay Yar Myint, Ikumi Genka, Masamori Shimabuku, Sayuri Suyama, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9420697/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 Japan consumes a relatively high percentage of oral broad-spectrum antibiotics, especially in the outpatient setting. Therefore, Japanese national action plan was established to reduce the use of total antimicrobials and oral broad-spectrum antibiotics by 2020. We aimed to evaluate our antibiotic stewardship program in accordance with the Japanese national action plan at our ambulatory clinic. Methods First, we assessed the baseline utilization rates of both total and broad-spectrum antibiotics at our clinic from April 2018 to March 2019. After implementing interventions, we collected data from April 2019 to October 2020, and compared the data with the baseline data for evaluation of outcomes. Results Total oral antibiotic uses significantly declined by 64%, and the use of macrolides, cephalosporins, and fluoroquinolones decreased by 75%, 62%, and 45%, respectively (p < 0.001). Conclusions We successfully reduced the use of total antimicrobials and oral broad-spectrum antibiotics except fluoroquinolones in accordance with the national target. Epidemiology Antimicrobial stewardship oral antibiotics broad-spectrum outpatient Figures Figure 1 Figure 2 Figure 3 Introduction Antimicrobial resistance (AMR) has been accelerated by inappropriate antibiotic use in medicine and food production. The absence of immediate global action could lead to increased disease burden as well as tremendous healthcare costs. 1 In Japan, oral antibiotics account for more than 90% of total antibiotic consumption. Compared with EU countries, Japan has a higher rate of oral broad-spectrum antibiotics such as third-generation cephalosporins, macrolides and fluoroquinolones and a lower rate of penicillin. 2 Most of those prescriptions occur in the outpatient setting. 3,4 An urgent response is needed to correct the rampant and frequent use of antibiotics in primary care and prevent drug resistance. Furthermore, antibiotics were among the most common drug groups associated with adverse drug events (ADEs) in the outpatient setting. 5 The national action plan for AMR of the Ministry of Health, Labor and Welfare (MHLW) aimed to reduce total antimicrobial use to two-thirds and the use of oral cephalosporin, quinolones and macrolides to one-half by 2020. 1 However, it has focused mainly on the outpatient units of hospitals. The establishment of the same plan will promote antimicrobial stewardship in ambulatory care. Therefore, we aimed to assess the utilization rates of both total and broad-spectrum antibiotics in the outpatient setting, establish interventions to reduce inappropriate use in accordance with the Japanese national action plan, and evaluate the outcomes of the interventions. Methods First, our project team, with the infection control physician as the leader, encouraged the outpatient administration and medical billing departments to consider the context and problems regarding antimicrobial resistance and the importance of the antibiotic stewardship program. We then examined the utilization rates of both total and broad-spectrum antibiotics at our outpatient department from April 2018 to March 2019. We presented the findings to the chief physician, the physician leader and the pharmacist of the outpatient department and planned interventions. Our strategies included the following: 1) physician education in accordance with the “Guide to Proper Use of Antimicrobial Drugs”, developed by the MHLW; 2) removing azithromycin from the default setting on prescription for upper respiratory tract infection; and 3) distributing patient education pamphlets explaining the unnecessary use of antibiotics for the common cold and acute pharyngitis, which we have failed to implement owing to a shift to telemedicine services for those with symptoms of respiratory tract infection as a measure against COVID-19 transmission. Ethical consideration The research was the secondary data analysis of the anonymized databases, and therefore, it does not require patients' consent; and the approval of an ethics committee. Data analysis We collected antibiotic prescription data from April 2019 to October 2020 and compared the baseline utilization rate with the rates within two timeframes: first, from the start of the online reservation system until the start of the antibiotic stewardship intervention (April 2019 to January 2020), and second, from the start of the antibiotic stewardship intervention (February 2020 to October 2020). We separated the timeframe for the online reservation system because it prevented unnecessary clinic visits for the common cold. The detailed calculation of the antibiotic utilization rate is described in Table 1 . We used R software V. 3.4.1 for data analysis. Table 1 Calculation of the antibiotic utilization rate 1) We first converted the dosage in grams for each antibiotic For example, the dosage of 120 tablets of azithromycin 250 mg was calculated as 250*120 = 30,000 mg = 30 grams 2) Using the ATC code of each antibiotic from WHO ATC/DDD system, we converted the dosage in grams into defined daily dose (DDDs). Azithromycin’s ATC code is J01FA10 and DDD is 0.3 gram. Therefore, Utilization rate in DDDs ⇒ 30/0.3 = 100DDD 3) Finally, we calculated the DDDs for 1000 outpatient visits per day (DID). Let’s say there were 2000 outpatient visits. Utilization rate in DID ⇒ {(100 DDD/number of outpatient visits) *1000}/365 days = 50/365 = 0.137 DID Results We observed the same trend as the national data in the primary care setting, which is the consumption of a higher percentage of broad-spectrum antibiotics, such as third-generation macrolides, third-generation cephalosporins and fluoroquinolones (see Fig. 1 ). Figure 2 shows that the utilization rate of antibiotics decreased significantly within the two time-frames, regardless of the number of outpatient visits. Total antibiotic use was reduced by 35% after the establishment of the reservation system and by 64% after the intervention (p < 0.001). All antibiotic use significantly decreased after the establishment of the online reservation system (see Fig. 3 ). In particular, use of azithromycin dramatically declined after being removed from the default setting on prescriptions for upper respiratory tract infection. Macrolide, third-generation cephalosporin and fluoroquinolone utilization rates were reduced by 75%, 62% and 45%, respectively (p < 0.001). Discussions In the baseline antibiotic use assessment, we observed the same trend as the national data, which was the consumption of a higher percentage of broad-spectrum antibiotics, such as third-generation macrolides, third-generation cephalosporins and fluoroquinolones. After interventions, the use of oral antibiotics has declined dramatically. We have achieved our goals of reducing total oral antibiotic use by two-thirds and the use of macrolides and cephalosporin by half, except for fluoroquinolones. However, online reservation systems and factors contributed by the COVID-19 pandemic, such as telemedicine, might have affected the outcomes, in addition to the measures we have taken. Significantly reduced prescription of antibiotics in the outpatient setting was also reported from the assessment of the National Database of Health Insurance Claims and Specific Health Check-ups of Japan (NDB) after implementing the National Action Plan in Japan. 6 That study also addressed the COVID-19 pandemic as the possible influencing factor and caution for a rebound after the pandemic. Therefore, we need to continually monitor the antibiotic use to ensure a robust antimicrobial stewardship program. Conclusions We have reduced the antibiotic utilization rate, which has a great impact on patients as well as public medical expenses. This project provided insights that we can start simple, compact and effective improvement projects that truly bring great changes to the workplace. Declarations Acknowledgements The authors thank staff at Tokyo Midtown Clinic for data collection. References The Government of Japan. Antimicrobial Resistance (AMR) Action Plan (2016) https://www.maff.go.jp/nval/yakuzai/pdf/japan_nationalactionplan_on_antimicrobial_resistance.pdf Ohmagari N (2019) National Action Plan on Antimicrobial Resistance (AMR) 2016–2020 and relevant activities in Japan. Glob Health Med 1(2):71–77. https://doi.org/10.35772/ghm.2019.01017 Higashi T, Fukuhara S (2009) Antibiotic prescriptions for upper respiratory tract infection in Japan. Intern Med 48:1369–1375. https://doi.org/10.2169/internalmedicine.48.1893 Ishida T, Hagiya H, Honda H, Nakano Y, Ogawa H, Obika M, Ueda K, Kataoka H, Hanayama Y, Otsuka F (2021) Antimicrobial prescription practices for outpatients with acute respiratory tract infections: A retrospective, multicenter, medical record-based study. PLoS ONE 16(11):e0259633. https://doi.org/10.1371/journal.pone.0259633 Shehab N, Patel PR, Srinivasan A, Budnitz DS (2008) Emergency department visits for antibiotic22-associated adverse events. Clin Infect Dis 47:735–743. https://doi.org/10.1086/591126 Hashimoto H, Kanda N, Yoshimoto H, Goda K, Mitsutake N, Hatakeyama S (2025) Significant reduction in antibiotic prescription rates in Japan following implementation of the national action plan on antimicrobial resistance (2016-20): a 9-year interrupted time-series analysis. JAC Antimicrob Resist 7(3):dlaf062. https://doi.org/10.1093/jacamr/dlaf062 Additional Declarations The authors declare no competing interests. Supplementary Files Authorcontributions.docx Author contributions Ethicaldeclarationsstatements.docx Ethical declaration statement Declarationofcompetinginterest.docx Declaration of competing interest 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-9420697","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Short Report","associatedPublications":[],"authors":[{"id":623280150,"identity":"55b6fe54-4e23-40df-8076-8ed487bb1f93","order_by":0,"name":"Khin Zay Yar 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Data\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9420697/v1/98ac2b6016d15edb6d148525.jpg"},{"id":107035340,"identity":"900c92d2-fa03-4cec-a1db-be3705e5b055","added_by":"auto","created_at":"2026-04-16 04:16:23","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1029244,"visible":true,"origin":"","legend":"\u003cp\u003eBaseline: April 2018 to March 2019\u003c/p\u003e\n\u003cp\u003eFirst period : After implementing reservation system (April 2019 to January 2020)\u003c/p\u003e\n\u003cp\u003eSecond period : After implementing antimicrobial stewardship program (February 2020 to October 2020)\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9420697/v1/997a4dd8af9d65fba5c09eb3.jpg"},{"id":107035343,"identity":"ffce3828-71ae-4ba6-98d5-d606e4179c67","added_by":"auto","created_at":"2026-04-16 04:16:24","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":943675,"visible":true,"origin":"","legend":"\u003cp\u003eBaseline: April 2018 to March 2019\u003c/p\u003e\n\u003cp\u003eFirst period : After implementing reservation system (April 2019 to January 2020)\u003c/p\u003e\n\u003cp\u003eSecond period : After implementing antimicrobial stewardship program (February 2020 to October 2020)\u003c/p\u003e","description":"","filename":"Figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9420697/v1/03a4df73249f88b06f6c309e.jpg"},{"id":107705181,"identity":"e35559a7-e21a-4078-b0ca-2d66d7b4d221","added_by":"auto","created_at":"2026-04-24 09:09:07","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3380666,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9420697/v1/fff2f732-8672-4ddf-b7f1-0cfa30eadc88.pdf"},{"id":107035338,"identity":"8b908072-dd00-40ea-8911-a65f0dcb9337","added_by":"auto","created_at":"2026-04-16 04:16:23","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":20227,"visible":true,"origin":"","legend":"\u003cp\u003eAuthor contributions\u003c/p\u003e","description":"","filename":"Authorcontributions.docx","url":"https://assets-eu.researchsquare.com/files/rs-9420697/v1/90191e65532da11726262866.docx"},{"id":107481319,"identity":"1ec20aac-2109-4cdd-8cea-bc6b9ee736c0","added_by":"auto","created_at":"2026-04-22 02:17:15","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":16499,"visible":true,"origin":"","legend":"\u003cp\u003eEthical declaration statement\u003c/p\u003e","description":"","filename":"Ethicaldeclarationsstatements.docx","url":"https://assets-eu.researchsquare.com/files/rs-9420697/v1/01d37442f22121b26eccc406.docx"},{"id":107035342,"identity":"681bd9ad-217c-4e9a-8438-15ad1cee28db","added_by":"auto","created_at":"2026-04-16 04:16:24","extension":"docx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":14504,"visible":true,"origin":"","legend":"\u003cp\u003eDeclaration of competing interest\u003c/p\u003e","description":"","filename":"Declarationofcompetinginterest.docx","url":"https://assets-eu.researchsquare.com/files/rs-9420697/v1/02d350a24891cb68727d3a90.docx"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eReducing oral broad-spectrum antibiotics use at an outpatient setting: an antimicrobial stewardship project\u003c/strong\u003e\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eAntimicrobial resistance (AMR) has been accelerated by inappropriate antibiotic use in medicine and food production. The absence of immediate global action could lead to increased disease burden as well as tremendous healthcare costs.\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e In Japan, oral antibiotics account for more than 90% of total antibiotic consumption. Compared with EU countries, Japan has a higher rate of oral broad-spectrum antibiotics such as third-generation cephalosporins, macrolides and fluoroquinolones and a lower rate of penicillin.\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e Most of those prescriptions occur in the outpatient setting. \u003csup\u003e3,4\u003c/sup\u003e An urgent response is needed to correct the rampant and frequent use of antibiotics in primary care and prevent drug resistance. Furthermore, antibiotics were among the most common drug groups associated with adverse drug events (ADEs) in the outpatient setting. \u003csup\u003e5\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eThe national action plan for AMR of the Ministry of Health, Labor and Welfare (MHLW) aimed to reduce total antimicrobial use to two-thirds and the use of oral cephalosporin, quinolones and macrolides to one-half by 2020.\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e However, it has focused mainly on the outpatient units of hospitals. The establishment of the same plan will promote antimicrobial stewardship in ambulatory care. Therefore, we aimed to assess the utilization rates of both total and broad-spectrum antibiotics in the outpatient setting, establish interventions to reduce inappropriate use in accordance with the Japanese national action plan, and evaluate the outcomes of the interventions.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eFirst, our project team, with the infection control physician as the leader, encouraged the outpatient administration and medical billing departments to consider the context and problems regarding antimicrobial resistance and the importance of the antibiotic stewardship program. We then examined the utilization rates of both total and broad-spectrum antibiotics at our outpatient department from April 2018 to March 2019. We presented the findings to the chief physician, the physician leader and the pharmacist of the outpatient department and planned interventions. Our strategies included the following: 1) physician education in accordance with the \u0026ldquo;Guide to Proper Use of Antimicrobial Drugs\u0026rdquo;, developed by the MHLW; 2) removing azithromycin from the default setting on prescription for upper respiratory tract infection; and 3) distributing patient education pamphlets explaining the unnecessary use of antibiotics for the common cold and acute pharyngitis, which we have failed to implement owing to a shift to telemedicine services for those with symptoms of respiratory tract infection as a measure against COVID-19 transmission.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eEthical consideration\u003c/h2\u003e \u003cp\u003eThe research was the secondary data analysis of the anonymized databases, and therefore, it does not require patients' consent; and the approval of an ethics committee.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eData analysis\u003c/h2\u003e \u003cp\u003eWe collected antibiotic prescription data from April 2019 to October 2020 and compared the baseline utilization rate with the rates within two timeframes: first, from the start of the online reservation system until the start of the antibiotic stewardship intervention (April 2019 to January 2020), and second, from the start of the antibiotic stewardship intervention (February 2020 to October 2020). We separated the timeframe for the online reservation system because it prevented unnecessary clinic visits for the common cold. The detailed calculation of the antibiotic utilization rate is described in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. We used R software V. 3.4.1 for data analysis.\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\u003eCalculation of the antibiotic utilization rate\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eWe first converted the dosage in grams for each antibiotic\u003c/p\u003e \u003cp\u003eFor example, the dosage of 120 tablets of azithromycin 250 mg was calculated as\u003c/p\u003e \u003cp\u003e250*120\u0026thinsp;=\u0026thinsp;30,000 mg\u0026thinsp;=\u0026thinsp;30 grams\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eUsing the ATC code of each antibiotic from WHO ATC/DDD system, we converted the dosage in grams into defined daily dose (DDDs).\u003c/p\u003e \u003cp\u003eAzithromycin\u0026rsquo;s ATC code is J01FA10 and DDD is 0.3 gram. Therefore,\u003c/p\u003e \u003cp\u003e\u003cb\u003eUtilization rate in DDDs \u0026rArr; 30/0.3\u0026thinsp;=\u0026thinsp;100DDD\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFinally, we calculated the DDDs for 1000 outpatient visits per day (DID). Let\u0026rsquo;s say there were 2000 outpatient visits.\u003c/p\u003e \u003cp\u003e\u003cb\u003eUtilization rate in DID \u0026rArr; {(100 DDD/number of outpatient visits) *1000}/365 days\u0026thinsp;=\u0026thinsp;50/365\u0026thinsp;=\u0026thinsp;0.137 DID\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eWe observed the same trend as the national data in the primary care setting, which is the consumption of a higher percentage of broad-spectrum antibiotics, such as third-generation macrolides, third-generation cephalosporins and fluoroquinolones (see Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows that the utilization rate of antibiotics decreased significantly within the two time-frames, regardless of the number of outpatient visits. Total antibiotic use was reduced by 35% after the establishment of the reservation system and by 64% after the intervention (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). All antibiotic use significantly decreased after the establishment of the online reservation system (see Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). In particular, use of azithromycin dramatically declined after being removed from the default setting on prescriptions for upper respiratory tract infection. Macrolide, third-generation cephalosporin and fluoroquinolone utilization rates were reduced by 75%, 62% and 45%, respectively (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Discussions","content":"\u003cp\u003eIn the baseline antibiotic use assessment, we observed the same trend as the national data, which was the consumption of a higher percentage of broad-spectrum antibiotics, such as third-generation macrolides, third-generation cephalosporins and fluoroquinolones. After interventions, the use of oral antibiotics has declined dramatically. We have achieved our goals of reducing total oral antibiotic use by two-thirds and the use of macrolides and cephalosporin by half, except for fluoroquinolones. However, online reservation systems and factors contributed by the COVID-19 pandemic, such as telemedicine, might have affected the outcomes, in addition to the measures we have taken. Significantly reduced prescription of antibiotics in the outpatient setting was also reported from the assessment of the National Database of Health Insurance Claims and Specific Health Check-ups of Japan (NDB) after implementing the National Action Plan in Japan.\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e That study also addressed the COVID-19 pandemic as the possible influencing factor and caution for a rebound after the pandemic. Therefore, we need to continually monitor the antibiotic use to ensure a robust antimicrobial stewardship program.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eWe have reduced the antibiotic utilization rate, which has a great impact on patients as well as public medical expenses. This project provided insights that we can start simple, compact and effective improvement projects that truly bring great changes to the workplace.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAcknowledgements\u003c/h2\u003e \u003cp\u003eThe authors thank staff at Tokyo Midtown Clinic for data collection.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eThe Government of Japan. Antimicrobial Resistance (AMR) Action Plan (2016) \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.maff.go.jp/nval/yakuzai/pdf/japan_nationalactionplan_on_antimicrobial_resistance.pdf\u003c/span\u003e\u003cspan address=\"https://www.maff.go.jp/nval/yakuzai/pdf/japan_nationalactionplan_on_antimicrobial_resistance.pdf\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOhmagari N (2019) National Action Plan on Antimicrobial Resistance (AMR) 2016\u0026ndash;2020 and relevant activities in Japan. Glob Health Med 1(2):71\u0026ndash;77. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.35772/ghm.2019.01017\u003c/span\u003e\u003cspan address=\"10.35772/ghm.2019.01017\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHigashi T, Fukuhara S (2009) Antibiotic prescriptions for upper respiratory tract infection in Japan. Intern Med 48:1369\u0026ndash;1375. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2169/internalmedicine.48.1893\u003c/span\u003e\u003cspan address=\"10.2169/internalmedicine.48.1893\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIshida T, Hagiya H, Honda H, Nakano Y, Ogawa H, Obika M, Ueda K, Kataoka H, Hanayama Y, Otsuka F (2021) Antimicrobial prescription practices for outpatients with acute respiratory tract infections: A retrospective, multicenter, medical record-based study. PLoS ONE 16(11):e0259633. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1371/journal.pone.0259633\u003c/span\u003e\u003cspan address=\"10.1371/journal.pone.0259633\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShehab N, Patel PR, Srinivasan A, Budnitz DS (2008) Emergency department visits for antibiotic22-associated adverse events. Clin Infect Dis 47:735\u0026ndash;743. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1086/591126\u003c/span\u003e\u003cspan address=\"10.1086/591126\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHashimoto H, Kanda N, Yoshimoto H, Goda K, Mitsutake N, Hatakeyama S (2025) Significant reduction in antibiotic prescription rates in Japan following implementation of the national action plan on antimicrobial resistance (2016-20): a 9-year interrupted time-series analysis. JAC Antimicrob Resist 7(3):dlaf062. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/jacamr/dlaf062\u003c/span\u003e\u003cspan address=\"10.1093/jacamr/dlaf062\" 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":true,"hideJournal":true,"highlight":"","institution":"Tokyo Midtown Clinic","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":"Antimicrobial stewardship, oral antibiotics, broad-spectrum, outpatient","lastPublishedDoi":"10.21203/rs.3.rs-9420697/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9420697/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eJapan consumes a relatively high percentage of oral broad-spectrum antibiotics, especially in the outpatient setting. Therefore, Japanese national action plan was established to reduce the use of total antimicrobials and oral broad-spectrum antibiotics by 2020. We aimed to evaluate our antibiotic stewardship program in accordance with the Japanese national action plan at our ambulatory clinic.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eFirst, we assessed the baseline utilization rates of both total and broad-spectrum antibiotics at our clinic from April 2018 to March 2019. After implementing interventions, we collected data from April 2019 to October 2020, and compared the data with the baseline data for evaluation of outcomes.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eTotal oral antibiotic uses significantly declined by 64%, and the use of macrolides, cephalosporins, and fluoroquinolones decreased by 75%, 62%, and 45%, respectively (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eWe successfully reduced the use of total antimicrobials and oral broad-spectrum antibiotics except fluoroquinolones in accordance with the national target.\u003c/p\u003e","manuscriptTitle":"Reducing oral broad-spectrum antibiotics use at an outpatient setting: an antimicrobial stewardship project","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-16 04:16:06","doi":"10.21203/rs.3.rs-9420697/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":"b1dff047-4cf0-45da-a6a9-29c926fb996e","owner":[],"postedDate":"April 16th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":66330858,"name":"Epidemiology"}],"tags":[],"updatedAt":"2026-04-16T04:16:06+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-16 04:16:06","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9420697","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9420697","identity":"rs-9420697","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}