Level of agreement between physical activity levels measured by ActiHeart and the International Physical Activity Questionnaire in persons with intellectual disability

Purpose: The purpose of this study was to determine the level of agreement between objective physical activity (PA) (ActiHeart^®) and subjective proxy-respondent International Physical Activity Questionnaire-short version (IPAQ-S) data in adults with intellectual disabilities (IDs).

Method: Fifty-eight participants wore ActiHeart^® monitors for seven consecutive days. Caregivers of each participant completed the IPAQ-S on behalf of the participant. Total PA, time spent in light, moderate, and vigorous activity as well as time spent being sedentary were assessed by the IPAQ-S and the ActiHeart^®. Results were compared by means of correlation analyses. The level of agreement was presented with Bland–Altman plots.

Results: Objective PA (ActiHeart^®) was higher (225.57?±?91.96?min/week) than IPAQ-S PA reported by care-givers (177.06?±?309.17?min/week). Weak significant correlations were observed between the ActiHeart^® and IPAQ-S instruments for sedentary behavior (r?=?0.31; p?=?0.04); no significant correlations for light (r=??0.04; p?=?0.8), moderate (r=??0.07; p?=?0.63), or vigorous PA (r=??0.2; p?=?0.18) were found. Limited agreement between objectively determine PA (ActiHeart^®) and IPAQ-S was found.

Conclusion: IPAQ-S is inaccurate when determining PA in persons with ID as it significantly underestimates the true levels of PA in this cohort.

• Implications for Rehabilitation

• Persons with intellectual disability (ID) report insufficient physical activity for health benefits.

• Physical activity is often determined by means of subjective proxy reporting.

• Objective physical activity measurements by means of combined heart rate and accelerometer are necessary to determine accurate levels of physical activity in persons with ID.

• Exercise interventions should be based on objective physical activity measurements.