Test-retest reliability of a questionnaire to assess physical environmental factors pertaining to physical activity

Background: Despite the documented benefits of physical activity, many adults do not obtain the recommended amounts. Barriers to physical activity occur at multiple levels, including at the individual, interpersonal, and environmental levels. Only until more recently has there been a concerted focus on how the physical environment might affect physical activity behavior. With this new area of study, self-report measures should be psychometrically tested before use in research studies. Therefore the objective of this study was to document the test-retest reliability of a questionnaire designed to assess physical environmental factors that might be associated with physical activity in a diverse adult population. Methods: Test and retest surveys were conducted over the telephone with 106 African American and White women and men living in either Forsyth County, North Carolina or Jackson, Mississippi. Reliability of self-reported environmental factors across four domains (e.g., access to facilities and destinations, functionality and safety, aesthetics, natural environment) was determined using intraclass correlation coefficients (ICC) overall and separately by gender and race. Results: Generally items displayed moderate and sometimes substantial reliability (ICC between 0.4 to 0.8), with a few differences by gender or race, across each of the domains. Conclusion: This study provides some psychometric evidence for the use of many of these questions in studies examining the effect of self-reported physical environmental measures on physical activity behaviors, among African American and White women and men. © 2005 Evenson and McGinn; licensee BioMed Central Ltd.