title: Primary end points in phase III clinical trials of severe head trauma: DRS versus GOS. The American Brain Injury Consortium Study Group.
abstract: The most commonly used primary end point in phase III clinical trials of severe head trauma is the Glasgow Outcome Scale (GOS), usually dichotomized to favorable (good) and unfavorable (poor) outcomes. The alternative endpoints include the Disability Rating Scale (DRS) with a 31-point scale. The purpose of this study was to compare DRS and GOS using the data collected from two completed clinical trials organized by the American Brain Injury Consortium and two pharmaceutical companies. The two outcome scales were examined and compared in terms of the correlation between the two scales, sensitivity, and p values between the differences between two arms of the trials. There was no indication that the DRS was more sensitive or advantageous relative to the dichotomized or four-category GOS. In addition, the highly significant correlation between the two outcome scales (r = 0.95; p < 0.0001) could not justify the DRS as an end point. The other problems with the DRS include the difficulty of determining the clinically meaningful difference in designing trials. The study suggested that the GOS is a better primary end point than DRS.
authors.affiliation: Department of Biostatistics, Medical College of Virginia of Virginia Commonwealth University, Richmond 23298-0032, USA.
authors.forename: S C
authors.initials: SC
authors.lastname: Choi
authors.forename: A
authors.initials: A
authors.lastname: Marmarou
authors.forename: R
authors.initials: R
authors.lastname: Bullock
authors.forename: J S
authors.initials: JS
authors.lastname: Nichols
authors.forename: X
authors.initials: X
authors.lastname: Wei
authors.forename: L H
authors.initials: LH
authors.lastname: Pitts
mesh_terms: D000328:Adult; D003289:Convalescence; D006259:Craniocerebral Trauma / Q000175:diagnosis / Q000188:drug therapy; D004185:Disability Evaluation; D015600:Glasgow Coma Scale; D006801:Humans; D018696:Neuroprotective Agents / Q000627:therapeutic use; D017063:Outcome Assessment, Health Care / Q000379:methods / Q000592:standards; D011569:Psychiatric Status Rating Scales / Q000592:standards; D011594:Psychometrics / Q000592:standards; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
chemical_list: D018696:Neuroprotective Agents