Greenhouse gas emissions and anthropogenic air pollution are changing the climate, creating complex spatial and temporal interactions that threaten health on a global scale. The existing literature has addressed the main effects of extreme temperature or air pollution on human health primarily with spatially coarse exposure estimates and without considering their interactions. The result is that environmental epidemiology on the health impacts of extreme heat and air pollution for aging populations is often out of date and likely underestimates these effects, in an era when our climate is increasingly unstable. Recent advances in satellite remote sensing and machine learning to predict ground conditions present a key opportunity to enable comprehensive study of the multifaceted effects of climate on healthy aging. Leveraging this opportunity, the CHAIRS-C Research Project will combine advanced spatiotemporal exposure modeling with national Medicare data, already in use at Brown, for case-crossover epidemiologic analyses. Our team combines expertise in environmental epidemiology, pharmacoepidemiology, big data health services research, and advanced biostatistical modeling. The long-term objectives of this project are to improve the quantification of the health impacts (emergency department visits and hospitalizations as well as all-cause mortality) associated with short-term extreme temperature, specific humidity, and fine particulate (PM2.5) air pollution on aging populations; identify vulnerable subpopulations; and construct a framework for the comparison of medications that increase the occurrence of climate-related illnesses. These results will help improve targeted public health interventions and may lead to actionable medication adjustments that modify the adverse effects of climate- related exposures. To achieve these objectives, the project will pursue the following specific aims: 1) Estimating the climate-related health impacts for older adults by linking new best-available temperature, specific humidity, and PM2.5 exposure estimates with Medicare records for aging populations, using a case- crossover design; 2) Quantifying the sensitivity to climate-related exposures within susceptible subpopulations to prioritize public health interventions with a particular focus on social determinants of health that contribute to climate-related health disparities; and 3) Examining comparative effect modification attributable to target medication classes on heat-related events, using propensity-score matching for medication selection within a case-crossover analytic framework for health effects. This 3-year research project is nested within the collaborative infrastructure of CHAIRS-C and will establish a platform for further solutions-oriented interdisciplinary research and community engagement. Constructing national place-based linked datasets for temperature, humidity, and PM2.5, as well as social determinants of health, demographic covariates, chr...