Reproducibility and validity of a self-administered physical activity questionnaire.
BACKGROUND
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
The simple, short questionnaires on activity and inactivity used in the Nurses' Health Study II are reasonably valid measures for epidemiological research.
Wolf
A M
AM
Channing Laboratory, Department of Medicine, Harvard Medical School, Boston, MA 02115.
Hunter
D J
DJ
Colditz
G A
GA
Manson
J E
JE
Stampfer
M J
MJ
Corsano
K A
KA
Rosner
B
B
Kriska
A
A
Willett
W C
WC
D000328:Adult; D004812:Epidemiologic Methods; D015444:Exercise; D005260:Female; D006801:Humans; D011897:Random Allocation; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires