Designing and Evaluating a Health System Resilient to Extreme Weather Events in Rural Madagascar

<i>Background:</i> Adapting health systems for climate change can lessen the negative impact of climate change on human health. Even when not targeting climate-health links explicitly, broad health system strengthening interventions (HSSis) can ensure that the health workforce, infrastructure, and networks are robust enough to respond to and recover from climate-driven shocks. <i>Objective:</i> We explored the ability of an HSSi in a rural health district of southeastern Madagascar to serve as a climate change adaptation in response to Cyclone Batsirai in 2022. <i>Method:</i> We conducted interrupted time series analyses of eight indicators of infectious disease and health system performance to assess the impact of Batsirai on two zones of the HSSi. We then examined how traditional domains of HSS, such as physical and human resources, combined with less formal domains, such as collective values, influenced health system resilience during this time. <i>Findings:</i> We found that the majority of indicators were resilient to Cyclone Batsirai, with only vaccination rates affected in the two months following the cyclone, particularly in the zone where the HSSi had only begun eight months prior. Changes in long-term trends were rare, and, when observed, revealed a slight slowing of progress, but not a regression to historical levels. After re-establishing the road network and providing additional supplies through an emergency response, the health system was able to resume routine service delivery without further external input, and health system indicators continued to improve. The agility and responsiveness of the health workforce were enabled by formalized protocols, a culture of flexibility, open communication, and data-informed action. <i>Conclusions:</i> HSSis that are designed to encourage local adaptation may increase health systems' resilience to extreme weather events, resulting in health systems better adapted to climate change overall.