Date of Award
Master of Science
Introduction: This study examined the validity of several methods of physical activity assessment in older adults. The physical activity questionnaires (PAQs) used included two designed for use with older adults known as the Yale Physical Activity Survey (YPAS) and the Physical Activity Scale for the Elderly (PASE) and one designed for use in the general population, the 7 Day Physical Activity Recall (PAR). These PAQs along with one accelerometer, the ActiGraph GT1M (GT1M), were examined in comparison to the criterion method, the SenseWear Pro 3 Armband (SP3).
Methods: Participants (n = 36; age = 69.7 ± 5.9 years) wore the SP3 and the GT1M for seven days . At the end of the seven days, participants completed the YPAS, PASE, and PAR. Pearson and Spearman correlation coefficients were used to examine significant relationships. Paired samples t-tests and Bland-Altman plots investigated further differences between methods.
Results: GT1M's estimates of daily steps were not significantly correlated (r = .369) with SP3 assessment of daily steps. The ACT-F (r = .620) and ACT-C (r = .524) equations each demonstrated a significant (P<0.01) correlation with SP3 estimates of physical activity energy expenditure (PAEE). Bland-Altman analysis indicated that the ACT-C underestimated PAEE by an average of 184 kcal/day. The PAR was the only one PAQ to demonstrate any significant associations with the SP3. These relationships include the PAR PAEE with SP3 PAEE (r = .464, P<;0.05), SP3 total energy expenditure (TEE) (r = .556, P<0.01), SP3 physical activity (PA) (r = .394, P<0.05) and the PAR PA with SP3 PA (r = .376, P<0.05). Bland-Altman plot assessments indicated that the PAR overestimated PAEE (1007 kcal/day) and PA (1294 min/week) more than either the PASE (PA = 324 min/week) or YPAS (PAEE = 476 kcal/week & PA = 230 min/week). The PAR also demonstrated a very strong systematic bias.
Discussion: While the GT1M did not show a significant correlation between estimates of step count with the SP3, it correlated reasonably with other estimates from the SP3 and provided the closest estimates in comparison to the SP3. Thus, it is a reasonable choice when assessing PA in older adults, but may not always be practical due to its high initial cost. As for the PAQs, while the PAR demonstrated the highest correlations, it also demonstrated high systematic bias and PA estimates were the furthest from average SP3 estimates of all methods examined. While PASE and YPAS provided slightly more accurate estimates, their correlations were not significant in comparison to the SP3. Estimates with PAQs were more accurate in individuals with lower PA levels, however may still be useful when used in those with higher PA levels to determine PA patterns.
Colleen Marie Campbell
Campbell, Colleen Marie, "Methods of physical activity assessment in older adults" (2012). Graduate Theses and Dissertations. 12809.