CHANGE IN RANKING ORDER OF PRESCRIBING PATTERNS BY AGE AND SEX STANDARDIZATION OF THE PRACTICE POPULATION - AUDIT MAY BE MISLEADING

Objective - To demonstrate whether standardization of practice populat ions by age and sex changes the internal prescription ranking order of a group of practices. Design - Data on the prescribing of cardiovascu lar drugs in a group of practices were obtained from a county-based da tabase. Information on the age, sex, and numbers of patients per pract ice mas also obtained, The direct standardization method was used to a djust practice populations for age and sex. Setting - The town of Rand ers, Aarhus County, Denmark, Subjects - 35 practices, 41 GPs, Main out come measures - Ranking of the 35 practices with respect to number of prescribed daily doses of cardiovascular drugs in crude utilization in dex and standardized utilization index. The slope of the regression cu rve of variation between the practices, Results - The change from crud e to standardized utilization index gave an entirely new ranking order of the practices. Only four practices did not change ranking position , while four moved more than ten places, The slope between highest and lowest ranked practice did not diminish after standardization. Conclu sion - Care should be taken when comparing peer prescribing patterns f rom crude utilization data, and we recommend prior age and sex standar dization. Our results are of value in creating a more reliable basis f or a debate on variation in prescribing patterns between peers.