An experiment in reducing interobserver variability of the examination for joint tenderness.

Abstract

This experiment was designed to test the feasibility of reducing interobserver variability of the joint examination by agreement on a standard examination. Six rheumatologists independently examined 6 patients with rheumatoid arthritis (RA) in predetermined order, before and after a standardization of examination techniques. Results of an analysis of variance showed a reduction of the percent of variability due to observers from 13.8%, before standardization, to 3.2% after standardization, and an improvement in the percent variability related to patient differences from 70.7%, before standardization, to 86.3% after standardization. Such a reduction in observer variability has a potential for allowing a reduction in sample sizes required for RA clinical trials.