Validity of a single question to assess habitual physical activity of community‐dwelling older people

摘要

The aim is to determine concurrent validity of a single self‐report habitual physical activity ( PA ) question against accelerometer‐based PA and mobility variables, and corresponding changes in self‐reported PA and mobility. Cross‐sectional and longitudinal data of the “Life‐space mobility in old age” ( LISPE ) cohort and its substudy on PA were utilized. At baseline, 848 community‐dwelling, 75‐ to 90‐year‐old people living independently in central Finland participated in home‐based interviews. One and 2?years later, 816 and 761 of them were reassessed by phone, respectively. Tri‐axial accelerometer data over 7?days were collected following the baseline assessments in a subsample of 174. Self‐reported habitual PA was assessed based on intensity and duration using a single question with seven response options (range: mostly resting to competitive sports). Mobility variables were as follows: life‐space mobility, walking difficulty over 500?m, and short physical performance battery. Statistically significant correlations were found between self‐reported habitual PA and mobility (Spearman correlation coefficient Rs?=?0.40–0.61) and accelerometer‐based PA variables [step counts (Rs?=?0.49), time in moderate (Rs?=?0.49) and low intensity (Rs?=?0.40) PA , and time in sedentary behavior (Rs?=??0.28)]. A decline in self‐reported habitual PA over time was associated with 5–10p decline in life‐space mobility ( PA improvement with 0–3p increase) and with developing a higher degree of walking difficulty (in 35–44% of participants). In conclusion, based on these results, the self‐report question to assess habitual PA is valid and responsive to change and thus useful for epidemiological research in community‐dwelling older people, also in follow‐up studies.