THE USE OF METHYLPHENIDATE IN MICHIGAN

Objective: To describe the epidemiologic findings associated with the use of methylphenidate hydrochloride among children aged 0 to 19 years in Michigan. Design: A population-based data set of all prescriptions filed with the Michigan Triplicate Prescription Program during February and March 1992 was analyzed, maintaining complete anonymity. Setting: State of Michigan. Participants: All patients receiving a prescription for methylphenidate who are residents of Michigan, and all physicians prescribing methylphenidate. Interventions: None. Main Outcome Measures: Descriptive data. Results: Eleven of 1000 Michigan residents between the ages of 0 and 19 years received a prescription for methylphenidate during the study period. Eighty-four per cent were boys. Boys aged 10 or 11 years received more prescriptions for methylphenidate than any other age group-43 per 1000. The number of children receiving prescriptions for methylphenidate ranged from 2.5 to 28 per 1000. The range for boys aged 10 or 11 years was from 9.6 to 117 per 1000. Primary care physicians wrote 84% of all prescriptions; pediatricians wrote 59% of the prescriptions for patients younger than 20 years old. Half of the prescriptions written by pediatricians were written by 5% of the pediatricians in the state. Conclusions: Michigan has been among the states with the highest per capita consumption of methylphenidate for the past 10 years. The major use of methylphenidate is for treatment of attention deficit hyperactivity disorder. The number of boys in Michigan aged 10 or 11 years who were treated with methylphenidate was similar to the national prevalence of the disorder, 3% to 5%. A tenfold variation was noted in the percentage of children medicated when the data were analyzed by county. Relatively few pediatricians account for the largest proportion of prescriptions. Future studies are needed to link the use of methylphenidate with diagnostic and treatment considerations in attention deficit hyperactivity disorder.