Use of addictive anxiolytics and hypnotics in a national cohort of incident users in Norway

Purpose To examine (1) incidence rates for treatment with addictive anxiolytics and hypnotics in Norway, (2) the proportions initiated by general practitioners (GPs), psychiatrists, and other physicians, and (3) the course of the treatment among incident users during a 3.5 year follow-up period. Method Data on all prescriptions of anxiolytics (ATC code N05B) and hypnotics (N05C) dispensed to the general population from 1 January 2004 to 31 August 2009 were extracted from the Norwegian Prescription Database and merged with data about GPs from the Norwegian Regular General Practitioner Scheme. Results One-year incidence rates per 1,000 inhabitants were 18.2 for anxiolytics, 24.5 for hypnotics, and 35.4 for anxiolytics and hypnotics combined. GPs and psychiatrists initiated the treatment to 75.4 and 2.4%, respectively. Only 30.8% received short-term treatment as recommended. Long-term use (11.8%) and heavy use (1.4%) were most common for treatments initiated by a GP, but the risk both of long-term and of heavy use was highest for patients initially treated by a psychiatrist. The amount redeemed during the first quarter was the strongest predictor of long-term use and of heavy use. However, even during the quarter with highest drug consumption, 81.5% of the patients received <1 DDD/day. Conclusions This study indicates that physicians' prescribing strategy towards initial users is crucial in order to prevent inappropriate drug use. There is a need to implement relevant guidelines and systems for structured clinical audits in general practice.