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

Abstract

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 10years for more than 200 psychoactive prescription drugs in the 67 million inhabitants in France. This was a nation-wide, repeated cross-sectional study. 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). 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. 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 6.6DDD/100 000 inhabitants/day). Oxycodone had the sharpest increase in the quantity doctor-shopped (+1000%, from 0.1 to 1.1DDD/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/. 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.