Assessing physical activity in people with mental illness: 23-country reliability and validity of the Simple Physical Activity Questionnaire (SIMPAQ)

Abstract

Background: Physical inactivity is a key contributor to the global burden of disease and disproportionately impacts the wellbeing of people experiencing mental illness. Increases in physical activity are associated with improvements in symptoms of mental illness and reduction in cardiometabolic risk. Reliable and valid clinical tools that assess physical activity would improve evaluation of intervention studies that aim to increase physical activity and reduce sedentary behaviour in people living with mental illness. Methods: The five-item Simple Physical Activity Questionnaire (SIMPAQ) was developed by a multidisciplinary, international working group as a clinical tool to assess physical activity and sedentary behaviour in people living with mental illness. Investigators from 43 centres in 23 countries collected reliability and validity data on the SIMPAQ from patients with DSM or ICD mental illness diagnoses. Test-retest repeatability was assessed one-week apart. Results: Criterion SIMPAQ validity was assessed against accelerometer-derived measures of physical activity. Data were obtained from 1,010 participants. The SIMPAQ had good test-retest reliability (Spearman rho approximately 0.70). Criterion validity for moderate-vigorous physical activity was comparable to studies conducted in general population samples. Criterion validity of the sedentary behaviour item was poor. An alternative method to calculate sedentary behaviour had greater criterion validity. This alternative method is recommended for use in future studies employing the SIMPAQ. Conclusions: The SIMPAQ is a brief measure of physical activity and sedentary behaviour that can be reliably and validly administered by health professionals.

Test-retest reliability and correlates of the Simple Physical Activity Questionnaire in Ugandan out-patients with psychosis

“…To this end, future research should compare the SIMPAQ scores with data obtained from criterion devices such as accelerometers. The Spearman rho correlation coefficient between the SIMPAQ moderate-vigorous physical activity and an objective assessment with an accelerometer was 0.25 for participants with available data (n=617, p<0.001) in the international SIMPAQ study 23 .…”

“…The current data show that all variables showed excellent reliability with Spearman Rho correlates ranging from 0.78 for structured exercise to 0.96 for walking. For comparison purposes with other self-report physical activity assessments, reliability correlations in the physical activity literature range from 0.34 to 0.89 22 while the only international study to date on the SIMPAQ including 1,010 participants with mental illness from 23 countries showed that test-retest correlations tanged from 0.63 for time spent in incidental activity (p<0.001) to 0.76 for time spent exercising and similarly for time spent walking (both p<0.001), indicating acceptable to good reliability 23 . Given this comparability, researchers and clinical practitioners should consider the SIMPAQ suitable as a reliable surveillance tool to assess levels of physical activity and sedentary behavior among out-patients with psychosis in low-resourced settings.…”