Validity of the International Physical Activity Questionnaire (IPAQ) for assessing moderate-to-vigorous physical activity and sedentary behaviour of older adults in the United Kingdom

BACKGROUND: In order to accurately measure and monitor levels of moderate-to-vigorous physical activity (MVPA) and sedentary behaviour (SB) in older adults, cost efficient and valid instruments are required. To date, the International Physical Activity Questionnaire (IPAQ) has not been validated with older adults (aged 60 years plus) in the United Kingdom. The current study aimed to test the validity of the IPAQ in a group of older adults for both MVPA and SB. METHODS: Participants wore an Actigraph GT3X+ for seven consecutive days and following the monitor wear participants were asked to complete the IPAQ. Statistical analysis included: Kolmogorov-Smirnov tests; descriptive analyses; Spearman's rho coefficients; and Bland-Altman analyses. RESULTS: A sample of 253 older adults were recruited (mean age 71.8 years (SD 6.6) and 57% male). In total, 226 had valid accelerometer and IPAQ data for MVPA and 228 had valid data for SB. Results showed the IPAQ had moderate/acceptable levels of validity (r = .430-.557) for MVPA. For SB, there was substantial levels of validity on weekdays (r = .702) and fair levels of validity (r = .257) on weekend days. Bland-Altman analysis showed inherent measurement error with the majority of participants tending to under-report both MVPA and SB. Results showed the majority of older adult's under-report their level of MVPA and SB when completing the IPAQ and the linear relationship above the mean shows an error from under to over reporting as the mean increases. CONCLUSIONS: Findings from the current study suggest that the IPAQ is better implemented in larger surveillance studies comparing groups within or between countries rather than on an individual basis. Findings also suggest that the IPAQ validity scores could be strengthened by providing additional detail of types of activities older adults might do on a daily basis, improving recall; and it may also be necessary to provide an example of a daily break down of typical activities performed. This may enable older adults to more fully comprehend the amount of time they may spend active, sitting and/or lying during waking hours.