PHARMACOEPIDEMIOLOGY AND PRESCRIPTION Antidepressant drug use in general practice: inter-practice variation and association with practice characteristics Received: 21 November 2002 / Accepted: 11 February 2003 / Published online: 30 April 2003 Ó Springer-Verlag 2003 Abstract Objective: The use of antidepressants (ADs) has escalated and prompted considerable debate. Many depressed patients go unrecognised or under-treated and the area of indication of the new ADs is widening. The aim of this study was to analyse (i) the variation in general practitioners’ prescribing of ADs by comparing with prescribing of other drug groups and (ii) whether the general prescribing behaviour, practice activity and demography are associated with the AD prescribing. Methods: Analysis of AD prescribing patterns among 174 general practices (93.5%) in the County of Funen, Denmark. Age- and sex-standardised 1-year incidences and prevalences of AD prescribing for patients listed were calculated using individual prescription data from Odense University Pharmacoepidemiologic Database. Data about health services and practice demography were obtained from the Health Insurance Register. The variation in AD 1-year prevalence was compared with other drug groups by a variation index (90%/10% per- centile). Univariate linear regression analysis was used to examine associations between practice characteristics and prescribing. Results: The 1-year prevalence of AD prescribing varied sixfold, no more than the prevalence of five other drug groups. Practices with high yearly: general prescribing prevalence, mean number of drugs per medicated patient, number of surgery consultations/100 patients and counsellings/100 surgery consultations showed the high- est yearly prevalence of AD prescribing. Single-handed practices had higher AD prescribing rates than partner- ships. The relative use of selective serotonin re-uptake inhibitors and other new ADs showed only little varia- tion (10% and 90% percentiles as close as 66–86%), but practices with high 1-year prevalence and incidence most often chose the new ADs. Conclusion: Analysis of inter-practice variation showed no extraordinary quality problems with regard to AD prescribing, but does not exclude that there might be problems. The general prescribing pattern of the general practitioners seems essential to their attitude to AD prescribing. The relationship between counselling and prescribing was a feature specific to ADs and deserves further investigation. Quality indicators are needed to understand differences in AD prescribing, and studies based on prescription data have to be supplemented with individual clinical data. Keywords Antidepressants Æ General practice Æ Physician practice patterns Introduction Since the introduction of the selective serotonin re-- uptake inhibitors (SSRIs) in 1988, many countries have reported a marked increase in the use of antidepressants (ADs) [1, 2]. Costs have escalated and the use of ADs has prompted considerable debate on an administrative, clinical and scientific level. The area of indication of the SSRIs and other new ADs is still widening beyond major depression and now includes anorexia, obsessive-com- pulsive disorder, panic disorder, bulimia, certain pains, etc. [3]. At the same time, it is claimed that many depressed patients go unrecognised in general practice [4, 5]. Suggestions of inappropriate use of ADs in pri- mary care [6, 7] may lead to the hypothesis that the inter- practice variation in the prescribing pattern of ADs is Eur J Clin Pharmacol (2003) 59: 143–149 DOI 10.1007/s00228-003-0593-3 Dorte Gilsa˚ Hansen Æ Jens Søndergaard Werner Vach Æ Lars Freng Gram Jens-Ulrik Rosholm Æ Jakob Kragstrup D. Gilsa˚ Hansen (&) Æ J. Søndergaard Æ J. Kragstrup Research Unit of General Practice, University of Southern Denmark, Winsløwparken 19, DK-5000 Odense C, Denmark E-mail: dgilsaa@health.sdu.dk Tel.: +45-655-03039 Fax: +45-659-18296 J. Søndergaard Æ L. Freng Gram Æ J.-U. Rosholm Clinical Pharmacology, University of Southern Denmark, DK-5000 Odense C, Denmark W. Vach Department of Statistics and Demography, University of Southern Denmark, DK-5000 Odense C, Denmark