Maine Carpal Tunnel Study: small area variations.

As is the case for all elective procedures, small area variations occur in rates of surgery for carpal tunnel syndrome. A 1993 analysis of Maine data demonstrates that carpal tunnel release rates across population-based service areas varied 3.5-fold, from 0.82 to 2.87 per thousand. Four areas had rates significantly higher and 2 were significantly lower than the state average of 1.44 per thousand. Among many potential factors influencing variations, physician practice patterns appear to be the major contributor.