Variation in Medical Practice: Implications for the Hospital Epidemiologist

Abstract

Why do two physicians faced with similar patients make different decisions about the care their patients should receive? This area of health services research has been energized by recent concerns about rising healthcare costs. In 1982, Wennberg and Gittelsohn described the great variation in surgical procedure rates throughout the northeastern United States during the 1970s. Population rates of hysterectomy and prostatectomy varied fourfold between local service areas; tonsilectomy rates varied sixfold. Differences in patient populations could not explain the variation in rates. The authors concluded that a large portion of the variability was attributable to the personal preferences of the surgeons practicing in the various communities. Similar differences in procedure rates are easy to replicate and are evident at several levels of aggregation. On larger scales, regional and international differences can be documented easily. On a smaller scale, practice variation within individual hospitals is frequently evident.