Doctor shopping for methylphenidate as a proxy for misuse and potential abuse in the 67 million inhabitants in France

Doctor shopping enables subjects to receive more than the prescribed dose out of any medical management, which suggests a search for high doses and makes doctor shopping a relevant proxy for misuse and potential abuse. Therefore, this study aimed to identify and characterize profiles of subjects with doctor-shopping behavior for methylphenidate in the entire French population. This study is a cross-sectional study of doctor-shopping behavior for methylphenidate in France, in 2016, using the Système national des données de santé, and accounting for overlapping prescriptions. Subjects who obtained >840 mg by doctor shopping were defined as subjects with heavy doctor-shopping behavior, and subjects who obtained >0 mg and ≤840 mg by doctor shopping were defined as subjects with light doctor-shopping behavior. A total of 63 739 subjects were included, and received 339.6 kg of methylphenidate. Among them, 216 (0.3%) subjects had heavy doctor-shopping behavior, and 313 (0.5%) subjects had light doctor-shopping behavior. Compared with subjects with light doctor-shopping behavior, subjects with heavy doctor-shopping behavior were older (64% of 30- to 49-year-old subjects vs. 77% of ≤17-year-old subjects; P < 0.001), received more concomitant dispensings of antipsychotics (37% vs. 26%; P = 0.008) and opioid maintenance treatments (50% vs. 6%; P < 0.001), and had more prescribers (4 [IQR = 2-5] vs. 2 [IQR = 2-3]; P < 0.001). In the French context where prescription and dispensing of methylphenidate are highly regulated and methylphenidate is much less used than in other countries, these results are a warning signal to avoid trivializing methylphenidate in adults.