Geographic variation in the prevalence of stimulant medication use among children 5 to 14 years old: Results from a commercially insured US sample

Objective. The purpose of this study was to evaluate geographic variation in the prevalence of prescription stimulant use and predictors of use among a nationally representative, commercially insured population 5 to 14 years old. Methods. Prescription claims activity from January 1, 1999 through December 31, 1999 for a continuously eligible population 5 to 14 years old was evaluated. Age-gender adjusted prevalence rates were estimated for each state. Multivariate logistic regression using hierarchical linear modeling was used to evaluate the impact of age, gender, number of child dependents, and region of the country on stimulant prevalence. The contextual effects of urban or rural residence, median income, percent white, and physician rate per 100 000 residents were also controlled for. Results. The 1-year prevalence of stimulant treatment for the entire study sample was 4.2%. Multivariate logistic regression indicated that stimulant prescription use was positively associated with age, male gender, fewer child dependents, living in higher income communities, and living in communities with greater percent white. Compared with children living in the Western region of the country, children living in the Midwest and South were 1.55 (99% confidence interval: 1.28-1.87) and 1.71 (99% confidence interval: 1.42-2.06) times more likely to consume at least 1 stimulant medication, respectively. Differences in stimulant prevalence across urban and rural residence were also noted. Conclusions. Geographic variation in the prevalence of stimulant use exists nationally, despite controlling for important predictors of use including age and gender. Possible reasons for the variation are discussed as are calls for additional research.