Prevalence and patterns of methylphenidate use in French children and adolescents

Objective The aim of the study was to describe the prevalence and utilization patterns of methylphenidate (MPH) in children and adolescents in France. Methods This was a population-based retrospective study in which the cohort consisted of patients for whom data were extracted from the dispensation drug claims database of the national health insurance (NHI) fund for self-employed workers. Annual prevalence of MPH use was evaluated on patients aged 6-18 years who were reimbursed for at least one MPH prescription a year. Between January 2004 and June 2005, features of MPH medication and user profile were described for the new starters having a screening period of 1 year without receiving a MPH prescription and a follow-up >= 12 months. Time to interruption of MPH regular use was analysed by Kaplan-Meier survival analysis. Mean duration of exposure to MPH treatment was computed with the 95% confidence interval (CI). Results Annual prevalence of MPH per 1000 persons was 1.1 in 2003, 1.5 in 2004 and 1.8 in 2005 (relative increase of 63.5%). New starters (n=447) received their first MPH prescription through the hospital (65.1%) or through private practitioners (34.9%). The user profiles were: short (16.6%), occasional (33.8%) and regular (49.6%). Among the new starters, the median time to interruption of MPH regular use was 10.2 months (95% CI: 7.9-12.4). The mean duration of exposure to MPH treatment was: occasional (4.9 months, 95% CI: 4.3-5.5) and regular (25.7 months, 95% CI: 24.6-26.8). Conclusion Although there is a low prevalence of MPH use in France, this survey revealed a wide profile of users and heterogeneous use patterns.