Validation of the Jackson Heart Study Physical Activity Survey in African Americans.
BACKGROUND
Physical inactivity has been consistently linked to cardiovascular disease, yet few instruments have been validated for assessment of physical activity in African Americans, a group particularly vulnerable to heart disease. The current study aimed to establish the psychometric properties of the activity survey used in the Jackson Heart Study (JHS) among African Americans, the JHS Physical Activity Cohort survey (JPAC).


METHODS
Test-retest reliability over 2 weeks was assessed using a convenience sample of 40 African Americans. Convergent validity with accelerometer and pedometer data were assessed in 2 samples from the JHS (N = 404 and 294, respectively).


RESULTS
Test-retest reliability was excellent, with intraclass correlations = .99 for the JPAC total and index scores. Higher JPAC total scores were significantly associated with higher raw accelerometer and pedometer counts. Spearman correlations between JPAC total scores and accelerometer (rho = .24) and pedometer counts (rho = .32) were consistent with these results. Most subscales were significantly correlated with the objective measures. The JPAC total score was most strongly associated with objectively-measured activity.


CONCLUSION
This study provides support for the reliability and validity of the JPAC as a tool for assessing physical activity among African Americans across a variety of domains.