Journal:Journal of Spinal Cord Medicine - JSCM (formerly Journal of the American Paraplegia Society)
Year, Volume, Issue, Page(s):14, 37, 3, 278-287
Article demonstrates how to design and power calculation of a clinical trial of spinal cord injury (SCI) pain using multiple pain sites per individual. The authors also discuss the consequences of failing to adjust for this factor and provide intraclass correlation (ICC) estimates for common pain outcome measures that may be used to power future clinical trials in SCI pain. Using an existing dataset from a past SCI pain clinical trial, the ICC was calculated for common pain outcome measures to illustrate appropriate corrections for powering, analyzing, and interpreting results from multiple pain sites per individual. Not accounting for the ICC can lead to incorrect power estimates in the design of a trial, and an inflated Type I error rate with a higher likelihood of misinterpretation of outcomes. Powering for future SCI pain trials and statistical analysis of trial outcomes may be substantially compromised if methods do not account for the intra-individual associations between pain sites, ultimately affecting study interpretations and evidence-based practice. ICC estimates based on SCI pain data are presented for purposes of estimating power for future trials.