Sharing resources to create a district drug formulary: a countywide controlled trial.

Abstract

BACKGROUND: Creating a drug formulary takes considerable time, but merely adopting one lacks local perspective and ownership. Sharing resources between several practices treads a middle path between these extremes, but is it effective? AIM: The aim of the study was to audit the influence of a district primary care drug formulary on prescribing by general practitioners. METHOD: A controlled trial was carried out to compare prescribing by 50 general practitioners from 11 urban and semirural practices in south Bedfordshire that participated in creating a district drug formulary with prescribing by all other general practitioners in the county. RESULTS: The proportion of prescription items that were for drugs listed in the formulary rose significantly in three therapeutics groups: cardiovascular (by 7-12% above control practice values); musculoskeletal (by 1-11% above control practice values); and obstetrics and gynaecology (by 6-9% above control practice values). The number of items prescribed per prescribing unit fell significantly in three therapeutic groups: musculoskeletal (by 1-7% below control practice values); nervous (by 7-12% below control practice values); and nutrition and blood (by 15-21% below control practice values). The estimated saving resulting from the creation of the formulary was 150,000 pounds (3000 pounds per doctor) per year. CONCLUSIONS: Sharing resources between practices to create a district-wide primary care drug formulary can lead to changes in prescribing and reduce costs sustained over 3 years.