AIMS To present the first nationwide, systematic, repeated assessment of doctor shopping (i.e. visiting multiple physicians to be prescribed the same drug) for more than 200 psychoactive prescription drugs, over 10 years in the 67 million inhabitants in France.

DESIGN Nationwide, repeated cross-sectional study. Setting and Participants Data from the French National Health Data System in 2010, 2015, and 2019 for 214 psychoactive prescription drugs (i.e. anesthetics, analgesics, antiepileptics, antiparkinson drugs, psycholeptics, psychoanaleptics, other nervous system drugs, and antihistamines for systemic use).

MEASUREMENTS The detection and quantification of doctor shopping relied on an algorithm that detects overlapping prescriptions from repeated visits to different physicians. We used two doctor-shopping indicators aggregated at population level for each drug dispensed to more than 5000 patients: (i) the quantity doctor-shopped, expressed in Defined Daily Doses (DDD), which measures the total quantity doctor-shopped by the study population for a given drug; and (ii) the proportion doctor-shopped, expressed as a percentage, which standardizes the quantity doctor-shopped according to the use level of the drug.

FINDINGS The analyses included about 200 million dispensings to about 30 million patients each year. Opioids (e.g. buprenorphine, methadone, morphine, oxycodone, and fentanyl) and benzodiazepines and non-benzodiazepine hypnotics (Z-drugs) (e.g. diazepam, oxazepam, zolpidem, and clonazepam) had the highest proportions doctor-shopped over the study period. In most cases, the proportion and the quantity doctor-shopped increased for opioids and decreased for benzodiazepines and Z-drugs over the study period. Pregabalin had the sharpest increase in the proportion doctor-shopped (from 0.28% to 1.40%), in parallel with a sharp increase in its quantity doctor-shopped (+843%, from 0.7 to 6.6 DDD/100,000 inhabitants/day). Oxycodone had the sharpest increase in the quantity doctor-shopped (+1000%, from 0.1 to 1.1 DDD/100,000 inhabitants/day), in parallel with a sharp increase in its proportion doctor-shopped (from 0.71% to 1.41%). Detailed results for all drugs over the study period can be explored interactively on https://soeiro.gitlab.io/megadose/.

CONCLUSIONS In France, doctor-shopping occurs for many drugs from many pharmacological classes, and it mainly involves opioid maintenance drugs, some opioids analgesics, some benzodiazepines and Z-drugs, and pregabalin.