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 populations by age and sex changes the internal prescription ranking order of a group of practices.


METHODS
Data on the prescribing of cardiovascular drugs in a group of practices were obtained from a county-based database. Information on the age, sex, and numbers of patients per practice was also obtained. The direct standardization method was used to adjust practice populations for age and sex.


METHODS
The town of Randers, Aarhus County, Denmark.


METHODS
35 practices, 41 GPs.


METHODS
Ranking of the 35 practices with respect to number of prescribed daily doses of cardiovascular drugs in crude utilization index and standardized utilization index. The slope of the regression curve of variation between the practices.


RESULTS
The change from crude 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.


CONCLUSIONS
Care should be taken when comparing peer prescribing patterns from crude utilization data, and we recommend prior age and sex standardization. Our results are of value in creating a more reliable basis for a debate on variation in prescribing patterns between peers.
Olesen
F
F
Research Unit for General Practice, University of Aarhus, Denmark.
Vedsted
P
P
Nørskov Nielsen
J
J
D000328:Adult; D000367:Age Factors; D002318:Cardiovascular Diseases / Q000188:drug therapy; D003718:Denmark; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D004363:Drug Utilization / Q000706:statistics & numerical data*; D017723:Drug Utilization Review; D005260:Female; D006801:Humans; D008297:Male; D008485:Medical Audit; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data; D012737:Sex Factors