Clinical trials in Duchenne dystrophy. Standardization and reliability of evaluation procedures.

A multiclinic, collaborative study has been designed to assess the natural progression and efficacy of treatment of Duchenne muscular dystrophy. This article describes the protocol for the evaluation technique and the method used to establish within (intraobserver) and between (interobserver) reliability of the protocol evaluation procedures. Standardized patient evaluations were used, and consistency of evaluation was monitored by a computer. The reliability of the measures was analyzed 1) within observers by comparing the results of each of the first three tests done by each evaluator for all patients and 2) between observers by comparing, at multicenter group meetings, the results of each of the four evaluators' tests of the same patient. We have demonstrated reliability for an evaluation method that will provide an objective foundation on which to claim a drug or therapeutic procedure does or does not have an effect in treating Duchenne muscular dystrophy.