Research note changes in the number of outpatient visits in Japan during the COVID-19 pandemic
BMC Research Notes volume 16, Article number: 70 (2023)
This study aimed to determine the change in the number of outpatient visits in Japan since the beginning of the COVID-19 pandemic, using data on the outpatient claims submitted by medical institutions to insurers in 2019 and 2020, from the National Database of Health Insurance Claims and Specific Health Check-ups. We calculated the total number of outpatient visits, and number of visits for individual diseases according to the International Classification of Diseases-10 codes on the claim form.
The number of outpatient visits per million people decreased by 9.98% in 2020 compared to 2019. Of the diseases included in the analysis, 71 showed a decrease in the number of visits by ≥ 1%. There were significant decreases in the number of visits related to infectious diseases (influenza, acute bronchitis, and acute laryngitis, etc.), and chronic diseases (hemorrhoids, cystic kidney disease, dyspepsia, and chronic sinusitis, etc.). The observed decreased rate of outpatient visit might have been due to, a decrease in the incidence of disease, a decreased frequency of visit by patients with the disease, or both. Our analysis method using actual health insurance claim data can be applied worldwide, where researchers have access to national information on health insurance claims.
The annual number of outpatient visits in Japan is 12.4 per capita, which is relatively high compared to other Organization for Economic Co-operation and Development (OECD) countries . Japan has a universal health insurance system for its population and within the framework of this system, the country has meticulously established a reimbursement system for high-cost medical care, and exemptions for individuals with limited income, which allows the public free access to medical care, both as policy and in practice. However, the frequency of outpatient visits reportedly decreased during the COVID-19 pandemic due to fear of getting infected . Therefore, this study aimed to determine the change in the number of outpatient visits in Japan since the beginning of the COVID-19 pandemic using a comprehensive administrative database containing data of almost 100 million Japanese residents.
The data were obtained from the National Database (NDB) of Health Insurance Claims and Specific Health Check-ups . This database contains data collected using standardized health insurance claim forms used by medical facilities for claiming reimbursement from insurers. The insurance claims of almost all citizens are digitized in the same format, regardless of the insurer type . The Ministry of Health, Welfare and Labor of Japan developed the NDB for planning, evaluating, and optimizing medical costs. The NDB data are available for analysis to a limited number of eligible applicants, including national administrative agencies, prefectures, universities, and national level medical insurers . As of March 2019, 99.2% of hospitals, and 94.8% of clinics in Japan had digitized all health insurance claims, making research using data from the NDB more accessible across the nation .
Based on the outpatient claims submitted monthly by medical institutions to insurers in 2019 and 2020, we calculated the total number of outpatient visits, and number of visits for each disease according to the International Classification of Diseases-10 (ICD-10) codes on the claim form. The number of visits was converted to units per million population using the following formulae:
If a patient received treatment for multiple diseases during a single visit, each treatment was counted as a visit for that particular disease. Diseases for which the number of outpatient visits increased from 2019 to 2020 received a negative score.
The difference in the number of visits in 2019 and 2020 was set as the denominator, and the difference in the number of visits for each disease in 2019 and 2020 was set as the numerator. From this, we calculated the percentage decrease in the visit rate per disease using the formula:
This study complied with the provisions of the World Medical Association Declaration of Helsinki (as amended by the 59th General Assembly, Seoul, the Republic of Korea, October 2008), and was approved by the Ethical Review Committee of Nara Medical University (No.: 1123). The requirement for informed consent was waived as the data were anonymized.
The number of outpatient visits per million people decreased by 9.98%, from 33,466 to 2019 to 30,127 in 2020. Of all the diseases included in the analysis, 71 showed a decrease in the number of visits by ≥ 1% (Table 1). There were significant decreases in the number of outpatient visits related to infectious diseases (such as influenza, viral infections of the skin, and mucous membranes, acute bronchitis, acute laryngitis, and acute upper respiratory tract infection), and chronic diseases (such as hemorrhoids, cystic kidney disease, dermatitis due to substances taken internally [ICD-10 code L27], dyspepsia, chronic sinusitis, and asthma).
This study focused on the decline in outpatient visits during the COVID-19 epidemic. The observed decrease in the outpatient visit rate might have been due to a decrease in the incidence of disease, or a decreased frequency of visit by patients with the disease, or both. For instance, as genetic factors play a role in the development of some cancers, and cancers may develop over a period of years or decades, a certain percentage of the population will always be affected, regardless of the pandemic. The decrease in the visit rate for such diseases was probably due to an avoidance of medical consultations rather than a decrease in the disease incidence. On the other hand, for diseases that are strongly influenced by short-term changes in behavior, the decrease in the visit rate may have been either due to a decreased incidence of the disease, or an avoidance of medical consultations, or both. Previous studies have reported a decrease in the incidence of pediatric viral respiratory tract infections due to social distancing , and an absent seasonal influenza epidemic during the 2020–2021 influenza season across all age groups , demonstrating evidence of a decrease in the incidence of infectious diseases due to the pandemic. Access to medical care is likely to have become limited as a result of a combination of prioritization of care for COVID-19 patients, together with avoidance of consultation by patients for fear of contracting COVID-19. This could explain the reduction in the number of visits for chronic conditions. As this study analyzed data retrospectively, prospective studies can be designed to further validate our results.
As our dataset included more than 100 million people, and Japan has universal health insurance coverage, we were able to identify large-scale societal trends in medical consultations associated with the COVID-19 pandemic, such as a decrease in the incidence of infectious diseases other than COVID-19, a temporary limited access to medical facilities, and the avoidance of medical consultations.
Our analysis method using actual health insurance claim data can be applied not only in Japan but also in other countries where researchers have access to national information on health insurance claims [6,7,8]. As universal health coverage continues to be implemented in low- and middle-income countries, in keeping with World Health Organization recommendations, consideration should be given to developing health insurance databases also, which can be used for research purposes to draw-up health care policies not only for management of health crises such as the COVID-19 pandemic, but also for strengthening health care systems in general [9, 10].
Japan needs to consider ensuring that all patients have the right to receive necessary outpatient care during future pandemics and otherwise. In Japan, prior to the COVID-19 pandemic, telemedicine was covered by medical insurance only for very limited applications compared to other countries. For example, telemedicine was only allowed for re-consultation in underpopulated areas. During the COVID-19 epidemic in Japan, expansion of the use of telemedicine was actively discussed, and eventually initial telemedicine consultations for patients suspected of having COVID-19 in urban areas were included in the coverage by medical insurance on a limited basis . We hope that Japan will review its policies with reference to reports regarding inclusion of medical insurance coverage of telemedicine consultations in other countries [12,13,14].
This study was unable to determine whether decreased incidence of disease or decreased access to care predominated in causing the decrease in the number of outpatient visits during COVID-19 pandemic. The underlying cause is likely to have varied from disease to disease.
The datasets analyzed during the current study are available from the corresponding author on reasonable request.
Organization for Economic Co-operation and Development
International Classification of Diseases-10
OECD. Doctors’ consultations, OECD Health Statistics: health care utilization; 2019 [cited Oct 30 2022]. Available from: https://data.oecd.org/healthcare/doctors-consultations.htm.
Takakubo T, Odagiri Y, Machida M, Takamiya T, Fukushima N, Kikuchi H, et al. Changes in the medical treatment status of japanese outpatients during the coronavirus disease 2019 pandemic. J Gen Fam Med. 2021;22(5):246–61. https://doi.org/10.1002/jgf2.432. PMID 34230872.
Okumura Y, Sakata N, Takahashi K, Nishi D, Tachimori H. Epidemiology of overdose episodes from the period prior to hospitalization for drug poisoning until discharge in Japan: an exploratory descriptive study using a nationwide claims database. J Epidemiol. 2017;27(8):373–80. https://doi.org/10.1016/j.je.2016.08.010. PMID 28242045.
Kuitunen I, Artama M, Mäkelä L, Backman K, Heiskanen-Kosma T, Renko M. Effect of social distancing due to the COVID-19 pandemic on the incidence of viral respiratory tract infections in children in Finland during early 2020. Pediatr Infect Dis J. 2020;39(12):e423-7. doi: https://doi.org/10.1097/INF.0000000000002845, PMID 32773660.
Kuitunen I. Influenza season 2020–2021 did not begin in Finland despite the looser social restrictions during the second wave of COVID-19: A nationwide register study. J Med Virol. 2021;93(9):5626-9. doi: https://doi.org/10.1002/jmv.27048, PMID 33945636.
Sim B, Nam EW. The impact of COVID-19 pandemic on outpatient visits for All-Cause and chronic diseases in Korea: A nationwide population-based study. Int J Environ Res Public Health. 2022 May 6;19(9):5674. doi: https://doi.org/10.3390/ijerph19095674, PMID 35565068.
Lambert J, Sandhu H, Kean E, Xavier T, Brokman A, Steckler Z et al. A strategy to identify event specific hospitalizations in large health claims databases. BMC Health Serv Res 2022 May 26;22(1):705. doi: https://doi.org/10.1186/s12913-022-08107-x, PMID 35619126.
Mansouri I, Raffray M, Lassalle M, de Vathaire F, Fresneau B, Fayech C et al. An algorithm for identifying chronic kidney disease in the French national health insurance claims database. Nephrol Ther. 2022;18(4):255 – 62. doi: https://doi.org/10.1016/j.nephro.2022.03.003. PMID 35773142.
Amporfu E, Agyei-Baffour P, Edusei A, Novignon J, Arthur E. Strategic health purchasing progress mapping: A spotlight on Ghana’s national health insurance scheme. Health Syst Reform. 2022 Mar 1;8(2):e2058337. doi: 10.1080/23288604.2022.2058337, PMID 35695801.
Lagomarsino G, Garabrant A, Adyas A, Muga R, Otoo N. Moving towards universal health coverage: health insurance reforms in nine developing countries in Africa and Asia. Lancet. 2012 Sep 8;380(9845):933 – 43. doi: https://doi.org/10.1016/S0140-6736(12)61147-7, PMID 22959390.
Kinoshita S, Kishimoto T. Current status and challenges of the dissemination of telemedicine in Japan after the start of the COVID-19 pandemic. Telemed J E Health. 2022 Aug;28(8):1220-4. doi: https://doi.org/10.1089/tmj.2021.0336, PMID 34918952.
Al-Zahrani MA, Alkhamees M, Almutairi S, Aljuhayman A, Alkhateeb S. Impact of COVID-19 on urology practice in Saudi Arabia. Risk Manag Healthc Policy. 2021 Apr 7;14:1379-92. doi: https://doi.org/10.2147/RMHP.S277135, PMID 33854387.
Knörr V, Dini L, Gunkel S, Hoffmann J, Mause L, Ohnhäuser T et al. Use of telemedicine in the outpatient sector during the COVID-19 pandemic: a cross-sectional survey of German physicians. BMC Prim Care. 2022 Apr 23;23(1):92. doi: https://doi.org/10.1186/s12875-022-01699-7, PMID 35461212.
Kim HS, Kim B, Lee SG, Jang SY, Kim TH. COVID-19 case surge and telemedicine utilization in a Tertiary Hospital in Korea. Telemed J E Health. 2022 May;28(5):666 – 74. doi: https://doi.org/10.1089/tmj.2021.0157, PMID 34757827.
This study was supported by the Health and Labour Sciences Research Grant (21IA1006) in Japan.
Ethics approval and consent to participate
This study complied with the provisions of the World Medical Association Declaration of Helsinki (as amended by the 59th General Assembly, Seoul, the Republic of Korea, October 2008) and was approved by the Ethical Review Committee of Nara Medical University (No.: 1123). The requirement for informed consent was waived as the data were anonymized.
Consent for publication
The authors declare no competing interests.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Machida, M., Nishioka, Y., Noda, T. et al. Research note changes in the number of outpatient visits in Japan during the COVID-19 pandemic. BMC Res Notes 16, 70 (2023). https://doi.org/10.1186/s13104-023-06336-9