Surveillance of Diabetes Prevalence Inequality and Disparities in Physical Inactivity in the U.S. – A Spatial Analysis

Diabetes prevalence has increased in recent decades in the U.S., and many of its risk factors have been identified; however, the spatial influence of physical inactivity prevalence on diabetes prevalence has not yet been investigated. The purpose of this study was to determine if the prevalence of physical inactivity has a geographical influence on diabetes prevalence in the U.S. The Bayesian structured additive regression modeling approach was conducted to determine the spatial association between physical inactivity prevalence and diabetes prevalence, after adjusting for the socioeconomic status of county residents. This study utilizes databases of Centers for Disease Control and Prevention and American Community Survey from 2004 to 2011. When physical inactivity prevalence increased 1 percent, the increase in the relative risk percentage for diabetes ranged from −1.58% (95% CI = -1.86, -1.32) to 1.55% (95% CI = 1.34, 1.74), where 2706 of 3109 counties (87.04%) displayed diabetes vulnerability with significantly positive relative risk percentages. Most of the vulnerable counties were located in South, Central, Northeast and Southeast Regions, where the highest diabetes prevalence is reported. We also conducted spatial comparisons with low, median-low, median-high, and high levels of physical-inactivity prevalence. A similar spatial vulnerability pattern for median-high physical inactivity prevalence levels was presented in these regions. This study identified the spatial vulnerability to diabetes prevalence associated with physical inactivity prevalence and, thereby, provides the evidence needed to prompt and establish enhanced surveillance that can monitor diabetes vulnerability in areas with high physical inactivity prevalence.