The Association Between Patient Upsurge and Telemedicine Utilization During the COVID-19 Period in Japan: A Seasonal Autoregressive Integrated Moving Average Analysis with 9 Years Claims Data

<b>Background:</b> While the coronavirus disease 2019 (COVID-19) pandemic led many countries to relax telemedicine regulations resulting in increased usage, limited research exists on telemedicine utilization patterns throughout the entire pandemic period. <b>Methods:</b> We conducted a retrospective study using the claims data with National Health Insurance in Kanagawa Prefecture, Japan, from April 2014 to March 2023. Using seasonal autoregressive integrated moving average modeling, we compared observed telemedicine usage with predicted values based on pre-COVID-19 data (April 2014-March 2020) and analyzed utilization patterns across different infection waves. <b>Results:</b> Telemedicine usage increased during peak infection periods of each wave following the first wave (April 2020). From the sixth wave onward (January 2022), COVID-19-related consultations accounted for over 50% of telemedicine usage. Subgroup analysis by disease showed that while most conditions had high proportions of patients with COVID-19 comorbidities, mental disorders maintained relatively low proportions. The highest utilization was observed during the seventh wave, significantly exceeding predicted values. <b>Conclusions:</b> Telemedicine usage increased in parallel with infection surges throughout the pandemic period, not just during the initial outbreak. The findings suggest the necessity of improving telemedicine service quality and accessibility during nonpandemic periods in preparation for future emerging infectious disease outbreaks. This study reveals both the critical role of telemedicine during infectious disease outbreaks and the varying utilization patterns across different diseases.