Comparison of prescribing unit with index including both age and sex in assessing general practice prescribing costs.BMJ 1993; 306 doi: http://dx.doi.org/10.1136/bmj.306.6876.496 (Published 20 February 1993) Cite this as: BMJ 1993;306:496
OBJECTIVE--To examine and compare the prescribing unit and a new prescribing index adjusting for age and sex in assessing general practice prescribing. DESIGN--Analysis of all prescriptions issued by two practices in one year. Use of data to derive a prescribing index adjusting for age and sex. Comparison of effect of prescribing unit and new index on relation between 80 practices' prescribing data and family health services authority average. SETTING--Newcastle and Gateshead Family Health Services Authorities. Two urban practices with eight doctors and combined list size of 16,300 patients. MAIN OUTCOME MEASURES--Cost and number of prescriptions issued to each age and sex group. Effect of index on relation between practice data and family health services authority average. RESULTS--The number of items prescribed and total costs rose with age. Although total costs were greater for women than for men, individual items cost more for men aged 25-84. Comparison of data adjusted by the prescribing unit and the new index with authority averages produced no significant differences except in a few practices with skewed age-sex demography. Results with the two indexes differed by over 5% in 34% (27/80) of practices for costs and in 14% (11/80) for items prescribed. CONCLUSIONS--The age and sex profile of a practice does not explain interpractice variation in prescribing patterns. Other unidentified factors need to be considered.