The relationship between alternative assessments of self-care ability in the elderly.

The self-care performance of 126 residents of old people's homes was assessed by self-report, informant rating and performance test. Scores on all three scales were related but associations were low and gross disagreements between measures were found in almost half of the cases. The associations between self-report and the other two measures were significantly lower than those between informant and performance ratings. There was no evidence of systematic bias in self-report related to cognitive or to affective impairment. It is probable that the three scales measure different aspects of dependency.