Positive Deviance in Obesity: Characteristics of counties with relatively low obesity rates

Background: Obesity is a national epidemic; however, substantial variation in obesity rates is apparent between and within states. We sought to identify counties with relatively low rates of obesity within states that have the highest obesity rates nationally. We termed these counties “positive deviants” and identified county-level factors associated with being a positive deviant.

Methods: We used data from the Robert Wood Johnson County Health Rankings and Ratings database to rank counties and states by obesity rates. We identified all counties with the lowest quintile obesity rates that were located in states with highest quintile obesity rates (i.e., positive deviant counties). We used fixed effects regression to identify measures of the healthcare environment, food and physical activity environments, and socio-demographic characteristics of the counties that were associated positive deviance. 

Results: Of 3,141 counties in the US, a total of 12 were positive deviants.  Compared with other counties, positive deviants had on average similar median incomes, higher per capita rates of dentists, physicians, and a larger percentage of adults reporting no leisure time physical activity. Positive deviant counties also were larger in population, had higher percentages of college graduates, lower rates of children in poverty, lower percentages of adults lacking insurance, and lower percentages of the workforce unemployed.

Conclusion: A small number of counties in the US are substantially different from their overall state in terms of obesity rates. A diverse set of factors including health care resources, physical activity, and socio-demographic characteristics distinguish these counties and may explain the deviance.