Primary end points in phase III clinical trials of severe head trauma: DRS versus GOS

Sung C. Choi, Anthony Marmarou, Ross Bullock, John S. Nichols, Xin Wei, Lawrence H. Pitts

Research output: Contribution to journalArticle

24 Scopus citations


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.

Original languageEnglish
Pages (from-to)771-776
Number of pages6
JournalJournal of Neurotrauma
Issue number10
StatePublished - Oct 1 1998
Externally publishedYes



  • Disability Rating Scale
  • Glasgow Outcome Scale
  • Outcome
  • Traumatic brain injury

ASJC Scopus subject areas

  • Clinical Neurology
  • Neuroscience(all)

Cite this

Choi, S. C., Marmarou, A., Bullock, R., Nichols, J. S., Wei, X., & Pitts, L. H. (1998). Primary end points in phase III clinical trials of severe head trauma: DRS versus GOS. Journal of Neurotrauma, 15(10), 771-776.