The increasing emphasis on evaluating outcomes has led to the developm
ent of standardized health status measures. Before using one it is vit
al to check its suitability for the intended purpose. Will the measure
detect the change or difference expected? Other more specific measure
s should be considered. Some focus on common impairments, such as cogn
itive dysfunction, whereas others focus on disabilities seen with spec
ific pathologies such as head injury. Developing new-measures is diffi
cult and should be avoided if possible.