Clinical investigation in Duchenne dystrophy: 2. Determination of the "power" of therapeutic trials based on the natural history

Muscle Nerve. 1983 Feb;6(2):91-103. doi: 10.1002/mus.880060204.


A prospective study of 114 patients with DMD provided data for "power" calculations for future therapeutic trials. There was a decline in strength of 0.4 units per year (on a 0-10 scale). Contractures of the iliotibial bands, hip flexors, and heel cords developed before 6 years. Contractures of other joints accompanied the increased use of wheelchairs. All children walked until 8 years with functional "improvement" between 3-6 years. Children of the same age varied widely in their strength, degree of contracture, and functional abilities. Fifteen percent of the patients appear to have a milder variety of the disease and are termed "outliers." To test a drug which might slow the disease to 25% of its original rate of progression, two groups (placebo and treatment) of 40 patients each would have to be followed for one year.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Clinical Trials as Topic
  • Contracture / drug therapy
  • Humans
  • Infant
  • Motor Skills / drug effects
  • Muscle Contraction / drug effects
  • Muscular Dystrophies / diagnosis
  • Muscular Dystrophies / drug therapy*
  • Respiration / drug effects