Kathleen Y. Wolin, Daniel P. Heil, Sandy Askew, Charles E. Matthews and Gary G. Bennett
The International Physical Activity Questionnaire-Short Form (IPAQ-S) has been evaluated against accelerometer-determined physical activity measures in small homogenous samples of adults in the United States. There is limited information about the validity of the IPAQ-S in diverse US samples.
142 Blacks residing in low-income housing completed the IPAQ-S and wore an accelerometer for up to 6 days. Both 1- and 10-minute accelerometer bouts were used to define time spent in light, moderate, and vigorous physical activity.
We found fair agreement between the IPAQ-S and accelerometer-determined physical activity (r = .26 for 10-minute bout, r = .36 for 1-minute bout). Correlations were higher among men than women. When we classified participants as meeting physical activity recommendations, agreement was low (kappa = .04, 10-minute; kappa = .21, 1-minute); only 25% of individuals were classified the same by both instruments (10-minute bout).
In one of the few studies to assess the validity of a self-reported physical activity measure among Blacks, we found moderate correlations with accelerometer data, though correlations were weaker for women. Correlations were smaller when IPAQ-S data were compared using a 10- versus a 1-minute bout definition. There was limited evidence for agreement between the instruments when classifying participants as meeting physical activity recommendations.
Steven P. Hooker, Anna Feeney, Brent Hutto, Karin A. Pfeiffer, Kerry McIver, Daniel P. Heil, John E. Vena, Michael J. LaMonte and Steven N. Blair
This study was designed to validate the Actical activity monitor in middle-aged and older adults of varying body composition to develop accelerometer thresholds to distinguish between light and moderate intensity physical activity (PA).
Nonobese 45 to 64 yr (N = 29), obese 45 to 64 yr (N = 21), and ≥65 yr (N = 23; varying body composition) participants completed laboratory-based sitting, household, and locomotive activities while wearing an Actical monitor and a portable metabolic measurement system. Nonlinear regression analysis was used to identify activity count (AC) cut-points to differentiate between light intensity (<3 METs) and moderate intensity (≥3METs) PA.
Using group-specific algorithms, AC cut points for 3 METs were 1634, 1107, and 431 for the obese 45 to 64 yr group, nonobese 45 to 64 yr group, and ≥65 yr group, respectively. However, sensitivity and specificity analysis revealed that an AC cut-point of 1065 yielded similar accuracy for detecting an activity as less than or greater than 3 METs, regardless of age and body composition.
For the Actical activity monitor, an AC cut-point of 1065 can be used to determine light and moderate intensity PA in people ≥45 years of age.