PT - JOURNAL ARTICLE AU - A Collie AU - P Maruff AU - M Makdissi AU - M McStephen AU - D G Darby AU - P McCrory TI - Statistical procedures for determining the extent of cognitive change following concussion AID - 10.1136/bjsm.2003.000293 DP - 2004 Jun 01 TA - British Journal of Sports Medicine PG - 273--278 VI - 38 IP - 3 4099 - http://bjsm.bmj.com/content/38/3/273.short 4100 - http://bjsm.bmj.com/content/38/3/273.full SO - Br J Sports Med2004 Jun 01; 38 AB - Neuropsychological (NP) testing is now often used to help to determine if the cognitive function of a concussed athlete has declined. The NP test score after concussion is compared with the baseline test score. Many clinicians simply subtract one from the other and make a clinical decision about the significance or otherwise of the resulting “difference score”. Such techniques are inadequate, as they fail to account for the many factors that may confound interpretation of serially acquired cognitive test scores. This is a review of a number of alternative approaches used in other areas of medicine for differentiating “true” changes from changes caused by these confounding factors. A case example is used to illustrate the effect that the statistical approach may have on clinical decision making.