Time series analysis of the impact of ambient temperature influence on healthcare service utilization by diabetes patients in the Special Capital Region of Jakarta, Indonesia: A study using Indonesian National Health Insurance data

The rising global incidence of diabetes poses a major health challenge, with growing evidence linking diabetes mellitus (DM) and ambient temperature. Due to compromised heat stress responses, people with diabetes are more vulnerable to extreme weather, common comorbidities, insulin resistance, and chronic inflammation. This study examines the impact of ambient temperature on healthcare utilization among diabetes patients in Jakarta, Indonesia, using data from the National Health Insurance program. The study used 2015-2023 sample data from Indonesia’s Healthcare and Social Security Agency (BPJS Health), comprising 2,407,300 participants diagnosed with DM. Claims data were stratified by residence, DM type, and healthcare facility type (primary vs. referral care). These were linked with daily, weekly, and monthly temperature records obtained from the Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG). Negative binomial regression model were applied to assess associations between temperature and DM-related healthcare visits, as the data indicated overdispersion in the count outcomes. Higher daily average temperatures were associated with increased healthcare visits, particularly in primary care. A 1 °C increase in the 7-day average temperature was associated with a 3% rise in patient visits, while a 14-day average increase was linked to a 4% rise. Lag structures reduced daily variability, highlighting consistent associations. Utilization patterns also showed peaks on Mondays and declines on weekends and public holidays. Diabetic patients are vulnerable to elevated temperatures, potentially due to impaired thermoregulation and medication effects. As climate change exacerbates extreme temperatures, Jakarta’s healthcare system may face increased demand. Interventions such as access to cool public spaces, enhanced patient monitoring, and resilient healthcare infrastructure are recommended. • The study uses nine years of BPJS Health claims (2015–2023) to assess the association between ambient temperature and diabetes-related healthcare utilization in Jakarta. • By including both primary care and referral visits, the study provides a holistic view of health service utilization patterns, offering deeper insights into how temperature affects different levels of care. • Higher temperatures were linked to increased visits in primary care but decreased visits in referral care, revealing differential impacts across healthcare levels. • Limitations include reliance on secondary data with missing covariates (e.g., age, sex, socio-economic status) and temperature data restricted to two of Jakarta’s five administrative cities, limiting generalizability.