Objective: To investigate the psychometric properties of the physical activity (PA) measure of the Women's Health Initiative (WHI).
Methods: Women diagnosed with breast cancer and enrolled in the Women's Healthy Eating and Living Study (average age 55 years) wore an accelerometer for 1 week and completed the 7-day Physical Activity Recall (PAR) and brief WHI measure.
Results: Both self-reports correlated 0.73 with the accelerometer and had 100% sensitivity for meeting the current PA guideline, but specificity was significantly higher for the PAR.
Conclusions: The WHI measure had comparable validity, sensitivity, and measurement bias compared to the widely accepted PAR.