We reviewed four prophylactic treatments for multiple sclerosis recently described in the literature: copolymer-1, interferon β-1b, cladribine, and oral methotrexate. Six problem areas are the subject of this commentary: 1) disease scales, 2) steroid use, 3) definition of exacerbation or relapse, 4) previous symptomatic/radiologic history, 5) magnetic resonance imaging, and 6) design variables: sample size, attrition rate, and power.
The studies were chosen because of their importance in understanding therapeutic responses in multiple sclerosis patients. Aspects to be considered were disease scales, steroid use, previous history, definition of exacerbation, magnetic resonance imaging, and statistical data. The design of each trial was slightly different. Data from each study were analyzed independently and collectively. The aforementioned variables were compared, and shortcomings were elucidated. Discrepancies between entry criteria and outcome measures were identified. The frequency, preparation, and duration of steroid use was contrasted. Relevant magnetic resonance imaging parameters and outcome criteria were examined. Comparison of total sample size, attrition rate, power, a error rate, and predicted detection of difference were culled, and future design models were explored.
This article reviews four current therapeutic trials involving multiple sclerosis patients. Differences and pitfalls of each study are compared. Statistical analysis among the trials is compared. The aim of this paper is to alert readers to the variability of current trials by direct comparison and to suggest design parameters for future trials.
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