The effect of chronic diseases on physical function. Comparison between activities of daily living scales and the Physical Performance Test

Aim: to verify the capacity of basic and instrumental activities of daily living (BADL and IADL) disability scales and of a performance-based test (Physical Performance Test; PPT) to detect the effect on the functional capacity of several common chronic conditions in elderly people. Method: a cross-sectional survey of the entire population aged 70 and over, living in Ospitaletto (Brescia, northern Italy) - 549 subjects; 89.6% of the eligible population; 179 males and 370 females - was carried out in 1992. A multi-dimensional questionnaire administered at the subject's home was used to collect information on demographics, presence of several common chronic diseases and BADL and IADL. Objective physical capacity was assessed using the PPT. Results: only cognitive deterioration and depression were independently associated with disability as detected by BADL or IADL scales. Cognitive deterioration, stroke, parkinsonism, heart disease and hearing and visual loss were independently associated with PPT. The performance at PPT remained statistically associated with most of the same diseases when the analysis was restricted to subjects with no BADL or IADL disability. Conclusion: a performance-based measure, such as PPT, may detect a functional limitation before it becomes measurable by traditional self-reported BADL and IADL scales.