Systematic assessment of non-medical use of prescription drugs using doctor-shopping indicators: A nation-wide, repeated cross-sectional study

Abstract

Aims: The aim of this study was to present the first nation-wide, systematic, repeated assessment of doctor-shopping (i.e. visiting multiple physicians to be prescribed the same drug) during 10 years for more than 200 psychoactive prescription drugs in the 67 million inhabitants in France. Design: This was a nation-wide, repeated cross-sectional study. Setting and Participants: Data are from the French National Health Data System in 2010, 2015 and 2019 for 214 psychoactive prescription drugs (i.e. anaesthetics, analgesics, antiepileptics, anti-Parkinson drugs, psycholeptics, psychoanaleptics, other nervous system drugs and antihistamines for systemic use). Measurements: The detection and quantification of doctor-shopping relied upon 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 approximately 200 million dispensings to approximately 30 million patients each year. Opioids (e.g. buprenorphine, methadone, morphine, oxycodone and fentanyl), benzodiazepines and non-benzodiazepine hypnotics (Z-drugs) (e.g. diazepam, oxazepam, zolpidem and clonazepam) had the highest proportions doctor-shopped during the study period. In most cases, the proportion and the quantity doctor-shopped increased for opioids and decreased for benzodiazepines and Z-drugs. Pregabalin had the sharpest increase in the proportion doctor-shopped (from 0.28 to 1.40%), in parallel with a sharp increase in the 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 the proportion doctor-shopped (from 0.71 to 1.41%). Detailed results for all drugs during the study period can be explored interactively at: https://soeiro.gitlab.io/megadose/. Conclusions: In France, doctor-shopping occurs for many drugs from many pharmacological classes, and mainly involves opioid maintenance drugs, some opioids analgesics, some benzodiazepines and Z-drugs and pregabalin.