Risk factors associated with multiple correlated health outcomes in the 500 Cities Project.

Reducing chronic disease is a major health challenge. Risk factors for chronic diseases are often studied at the individual level, even though interventions and policies may be implemented at the city level. We use an ecologic study design with city-level data, to simultaneously assess the relative impact of unhealthy behaviors and preventive care measures on multiple chronic disease health outcomes. We analyze a newly available, large national dataset called the 500 Cities Project. We examine the associations between city-level prevalence of unhealthy behaviors, clinical preventive service use, and all chronic disease health outcomes in 500 of the largest U.S. cities for year 2014. After adjusting for age and demographic characteristics, using MANOVA we found that the top three risk factors for all health outcomes are smoking (Pillai's trace = 0.95, approx. F = 688.7, p-value < 0.0001), lack of physical activity (Pillai's trace = 0.91, approx. F = 380.0, p-value < 0.0001) and binge drinking (Pillai's trace = 0.91, approx. F = 348.8, p-value < 0.0001), which are statistically significant after adjusting for multiple comparisons. Higher prevalence of an annual dental checkup, a preventive service use measure, is correlated with lower prevalence of several chronic diseases such as diabetes (correlation coefficient r = -0.88), poor physical health (r = -0.91), stroke (r = -0.85), cardiovascular disease (r = -0.83) and poor mental health (r = -0.82). Identifying important chronic disease risk factors at the city-level may provide more actionable information for policymakers to improve urban health.