Demographic-specific Validity of the Cancer Prevention Study-3 Sedentary Time Survey

Purpose This study examined the 1-yr test–retest reliability and criterion validity of sedentary time survey items in a subset of participants from a large, nationwide prospective cohort. Methods Participants included 423 women and 290 men age 31 to 72 yr in the Cancer Prevention Study-3. Reliability was assessed by computing Spearman correlation coefficients between responses from prestudy and poststudy surveys. Validity was assessed by...