Guidelines for assessing the predictive value of neuropsychological measures

One of the criteria we need to consider when evaluating a manuscript, is how far the findings of the study can be generalised. This article draws attention to two key factors that influence the predictive value of research findings. The principal application of these ideas is to studies that report differences on neuropsychological tests, neurobiological measures (e.g. neuropathology) or psychopharmacological treatments between groups of patients or between patients and controls. Assuming that the study under review has been well conducted and the data are trustworthy, the predictive value of the findings depends on (a) the way in which the samples have been selected, and (b) the prevalence of the disorder in the population.