Assessing physical activity in people with posttraumatic stress disorder: feasibility and concurrent validity of the International Physical Activity Questionnaire– short form and actigraph accelerometers

Background: Posttraumatic stress disorder (PTSD) is reportedly associated with lower rates of physical activity participation despite the known benefits of regular physical activity for improving both mental and physical health. However, no studies have evaluated the validity or feasibility of assessing physical activity within this population resulting in uncertainty around the reported lower rates of physical activity participation. This study aimed to evaluate the feasibility and concurrent validity of the International Physical Activity Questionnaire-Short Form (IPAQ-SF) and the Actigraph accelerometer (an objective physical activity monitor) among inpatients with PTSD.

Methods: Fifty-nine adult hospital inpatients with a Diagnostic Statistical Manual Mental Disorder-IV-TR diagnosis of primary PTSD (mean age = 49.9 years; 85% male) participated in the study. Participants were asked to wear an Actigraph accelerometer for seven consecutive days then complete the IPAQ-SF. The Spearman rho correlation coefficient compared the amount of moderate to vigorous physical activity (MVPA) measured with the Actigraph and the total physical activity reported in the IPAQ-SF.

Results: Lower than expected compliance with wearing accelerometers (<4 days valid data) (n = 20) was found suggesting that the use of accelerometers within this population may not be feasible. Complete IPAQ-SF data were available for 45 participants (76%) indicating that this tool also has its limitations in this population. The Spearman rho was 0.46 (p = 0.01) for the 29 participants with four or more valid days of accelerometer data (as per literature standards) and available IPAQ-SF.

Conclusion: The IPAQ-SF and the Actigraph accelerometer have limitations in people with PTSD but in those able to provide data, show correlations of a magnitude comparable to those observed in the general population. The development and testing of mental health specific tools may enhance measurement of physical activity in this population.