Practice variation in rheumatologists' encounters with their patients who have rheumatoid arthritis.

This article examines practice variation among rheumatologists in their use of time and procedures in follow-up outpatient encounters with rheumatoid arthritis patients. It focuses on differences across individual physicians rather than differences in populations of patients. In addition, the total variance is divided into parts due to patient characteristics, the providers' economic and other incentives to do procedures or reduce contact time, individual practice styles, and the random sampling of encounters. Data are taken from a stratified random sampling of U.S. rheumatologists. Analyses are based on 1,154 outpatient follow-up encounters with rheumatoid arthritis patients provided by 66 physicians, each of whom reported at least ten such encounters. There are large differences among the physicians in visit length, number of monitoring procedures used per encounter, and whether the encounter included measurements of complete blood count/urinalysis or erythrocyte sedimentation rate. Individual practice style differences are far more important causes of the variation that was observed among providers than are patient differences or practice incentive differences. It was determined that 5-40% of the cost of specific management activities could be saved by reducing the highest use.