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Clinical investigation in duchenne dystrophy: 2. Determination of the “power” of therapeutic trials based on the natural history
Author(s) -
Brooke Michael H.,
Fenichel Gerald M.,
Griggs Robert C.,
Mendell Jerry R.,
Moxley Richard,
Miller J. Philip,
Province Michael A.
Publication year - 1983
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880060204
Subject(s) - muscle contracture , medicine , natural history , heel , contracture , placebo , clinical trial , physical therapy , duchenne muscular dystrophy , muscular dystrophy , pediatrics , surgery , pathology , alternative medicine , anatomy
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.