Clinical interest: a study of the influence on general practitioners' prescribing

To analyse the association between general practitioners' clinical interest and prescribing rates in four clinical areas: dyspepsia, depression, headache and diabetes.

Data concerning general practitioners' prescribing during 2004 were retrieved from a pharmacy database and linked with data from a physician questionnaire and the National Health Insurance Register. To counterbalance differences in practice populations all 1-year prevalences of prescribing were standardised according to age and gender. Participants were asked 'To what extent do you find the following areas interesting from a professional point-of- view?' Four rating categories were used. The association between clinical interest and standardised prescribing rates was investigated using logistic regression, the Kruskal-Wallis test and a trend test.

A total of 68 (72%) single-handed general practitioners representative of the total group completed the questionnaire. We observed a two-fold ratio between the 90% and the 10% percentiles of the 1-year prevalences of antisecretory drugs, antidepressants, migraine drugs as well as anti-diabetics. The variation in prescribing of antidepressant and antisecretory drugs was far above chance level. No significant association with clinical interest could, however, be observed for any of the four clinical areas.

General practitioners' prescribing of the four classes of medical drugs varied considerably. However, only part of this variation was based on chance. This study did not confirm our hypothesis that general practitioners' level of clinical interest in one area corresponds with their prescribing of drugs used within that area.