Validity of sitting time scores from the International Physical Activity Questionnaire-Short Form in multiple sclerosis.

Abstract

The current study examined the validity of scores from the sitting time item on the International Physical Activity Questionnaire-Short Form (IPAQ-SF) in a sample of persons with multiple sclerosis (MS). Persons with MS were recruited through the distribution of printed letters to a random sample of 1,000 persons from the North American Research Committee on MS registry. Two hundred ninety-five persons with MS were interested and volunteered to wear an ActiGraph accelerometer for a 7-day period and complete a battery of questionnaires that included the IPAQ-SF and Godin Leisure-Time Exercise Questionnaire over this period of time. IPAQ-SF sitting time scores were consistently and moderately correlated with all of the sedentary behavior metrics from the accelerometer (range of r between .295 and .431), and the correlations were stronger than those between self-reported physical activity and sedentary metrics from the accelerometer (range of r between -.087 and .163). The correlations between IPAQ-SF sitting time scores with the accelerometer-derived sedentary behavior metrics were still statistically significant in the analyses controlling for physical activity (range of parametric correlations between .281 and .411). The correlation analysis indicated consistent, moderate correlations between IPAQ-SF sitting time scores and device-measured estimates of both the volume and pattern of sedentary behavior, and the correlations were (a) stronger than those for self-reported physical activity and (b) independent of self-reported physical activity. Such results provide initial evidence for the validity of inferences from IPAQ-SF sitting time scores as an overall measure of sedentary behavior in persons with MS. (PsycINFO Database Record (c) 2019 APA, all rights reserved).