Consistently inconsistent: a snapshot of across- and within-state disparities in the prevalence of childhood overweight and obesity.

BACKGROUND: The epidemic of childhood overweight and obesity is characterized by known disparities. Less is known about how these disparities vary across and within the state in which a child lives. OBJECTIVE: To examine the magnitude and patterns of across- and within-state differences in the prevalence of childhood overweight and obesity according to children's insurance type (public versus private), household income level, race (non-Hispanic black versus non-Hispanic white), and ethnicity (Hispanic versus non-Hispanic). METHODS: State-level overweight and obesity prevalence rates for children aged 10-17 were calculated by using data from the 2003 National Survey of Children's Health. Statistical significance of across-state variation was assessed. Disparity ratios assessed within-state equity according to children's insurance type, income, race, and ethnicity. State ranks on overall prevalence and ranks on disparity indices were correlated and regression models were fit to examine within-state consistency, state-level clustering effects and whether the effect of child characteristics varied across key population subgroups. RESULTS: Prevalence of childhood overweight and obesity varied significantly across states. A total of 31 states had a prevalence lower than the national rate of 30.6% (14 statistically significant), and 20 had higher rates (9 statistically significant). Within-state disparity indices ranged from a low of 1.0 (no disparity) to a high of 3.44 (nearly 3.5 times higher). Correlations between state ranks on overall prevalence and their ranks on disparity indices were not significant for the insurance type, income, or race disparity groups examined. A modest state-clustering effect was found. Compared with non-Hispanic white children, the effect of lower household income and lower household education level education were significantly less for non-Hispanic black and Hispanic children, who were more likely to be overweight or obese regardless of these other factors. CONCLUSIONS: Disparities in the prevalence of childhood overweight and obesity vary significantly both within and across states. Patterns of variation are inconsistent within states, highlighting the need for states to undertake state- and population-specific analyses and interventions to address the epidemic.