Impact of an interest in asthma on prescribing costs in general practice.

OBJECTIVE To examine the effect on total prescribing costs and prescribing costs for respiratory drugs for practices with at least one general practitioner with a special interest in asthma. DESIGN Postal questionnaire survey. SETTING General practitioners in England and Wales. SUBJECTS 269 members of the General Practitioners in Asthma Group, of whom 103 agreed to participate. MAIN MEASURES Individual practitioners' and their practices' PACT prescribing costs from the winter quarters of 1989-90 compared with average costs for their family health services authority (FHSA) and a notional national average of all FHSAs combined. RESULTS The response rate was 57%; the average total prescribing costs for the practices of the 59 respondents were significantly lower than those of their respective FHSAs (mean difference 505 pounds per 1000 patients per quarter (95% confidence interval -934.0 to -76.2, p = 0.022) and lower than the national average. The average prescribing costs for respiratory drugs for the practices were significantly greater than those for their FHSA (195 pounds per 1000 patients per quarter (84.4 to 306.0, p = 0.001) and the national average. Both types of costs varied widely. CONCLUSION An interest in asthma care in general practice is associated with higher average prescribing costs for respiratory drugs but no increase in overall prescribing costs compared with those for respective FHSAs and national averages. IMPLICATIONS FHSAs and their medical advisors should not examine high prescribing costs for individual doctors or one therapeutic category but in the context of practice total costs.