Reproducibility and Validity of a Self-Administered Physical Activity Questionnaire

TLDR

The study examined the reproducibility and validity of self‑administered physical activity questionnaires in representative and African‑American samples of the Nurses’ Health Study II cohort. Participants completed repeat questionnaires two years apart, with past‑week recalls and 7‑day diaries used as reference methods and sent four times over a one‑year period. The questionnaires showed moderate test‑retest correlations (0.59 in the representative sample, 0.39 in the African‑American sample) and good validity against recalls (0.79–0.83) and diaries (0.62–0.59), with inactivity correlations of 0.52–0.55 and 0.41–0.44, indicating reasonable validity for epidemiological research.

Abstract

The reproducibility and validity of self-administered questionnaires on physical activity and inactivity were examined in a random (representative) sample of the Nurses' Health Study II cohort and a random sample of African-American women in that cohort. Repeat questionnaires were administered 2 years apart. Past-week activity recalls and 7-day activity diaries were the referent methods; these instruments were sent to participants four times over a 1-year period. The 2-year test-retest correlation for activity was 0.59 for the representative sample (n = 147) and 0.39 for the African-American sample (n = 84). Correlations between activity reported on recalls and that reported on questionnaire were 0.79 and 0.83 for the representative and African-American samples, respectively. Correlations between activity reported in diaries and that reported on questionnaire were 0.62 and 0.59, respectively. Test-retest coefficients for inactivity were 0.52 and 0.55, respectively. Correlations between inactivity reported in diaries and that reported on questionnaire were 0.41 and 0.44, respectively. The simple, short questionnaires on activity and inactivity used in the Nurses' Health Study II are reasonably valid measures for epidemiological research..