Spatial risk factors are increasingly recognized to predict cardiovascular events independently of traditional risk factors. However, these spatial risk factors have been studied only individually and primarily in high-income countries. Hypothesis: We hypothesize that spatial risk factors independently predict all-cause and cardiovascular mortality.

We developed exposure models for the following spatial risk factors in Golestan Provence, Iran: outdoor air pollution, proximity to traffic, proximity to health facilities, population density, land cover, socioeconomic environment, and light-at-night. Spatial exposures were assigned to 50,045 individuals in the Golestan Cohort Study, who have been followed-up for up to 12 years. Using a multivariable Cox proportional hazards spatial frailty model, we determined the impact of these exposures, as well as household fuel use and traditional risk factors, on cardiovascular mortality.

Spatial surfaces demonstrated spatial variability of the spatial risk factors (Figure), and outdoor air pollution also displayed temporal variability. Exposure to outdoor air pollution 5 years prior to enrollment, household kerosene and biomass fuel use, and proximity to advanced health facilities independently increased total and cardiovascular mortality (Table).

Both outdoor air pollution and household fuel use independently predicted cardiovascular mortality in a middle-income country. Following this approach, future studies can better estimate the total impact of the environment on cardiovascular events.