Healthcare system preparedness as a mediating factor in climate-driven tuberculosis outcomes: an ecological study

Climate change may influence tuberculosis (TB) transmission through environmental and health system pathways. It is important to understand how the health system can adapt to reduce the impact of climate change on TB transmission.

We conducted an ecological study using district-level data from the Indonesian Health Facility Research Survey, the National Health Insurance data sample registry, and monthly climate indicators (temperature, humidity, precipitation) for 2019. Mediation analysis was applied to assess the role of healthcare preparedness in mediating the relationship between climatic variability and TB incidence.

Healthcare preparedness fully mediated the association between humidity and TB incidence. The indirect effect through healthcare preparedness was statistically significant (α × β = 0.0021, 95% CI: 0.0008, 0.0035), while the direct effect was not (c¹ = 0.0102, 95% CI: -0.0013, 0.0217). Approximately 17.1% of the total effect of humidity on TB (c = 0.0123, 95% CI: 0.0009, 0.0237) mediated through healthcare preparedness. For temperature, the relationship with TB was partially mediated, with a small but significant negative indirect effect (α × β = -0.0002, 95% CI: -0.0003, -0.0001), indicating that adequate healthcare may offset about 14.3% of temperature-related TB risk, while a significant direct effect remained. No significant mediation was found for precipitation.

These findings highlight the importance of targeted investments to strengthen healthcare systems in high-burden, climate-vulnerable districts. Integrating climate adaptation into TB control programs and enhancing surveillance are essential to ensure accurate burden estimation, effective resource allocation, and resilience against the combined challenges of climate variability and TB transmission.