Validity of a physical activity questionnaire among African-American Seventh-day Adventists.
BACKGROUND
Physical activity has been identified as an important predictor of chronic disease risk in numerous studies in which activity levels were measured by questionnaire. Although the validity of physical activity questionnaires has been documented in a number of studies of U.S. adults, few have included a validation analysis among blacks. We have examined the validity and reliability of a physical activity questionnaire that was administered to 165 black Seventh-day Adventists from Southern California.


METHODS
Subjects completed a self-administered physical activity questionnaire and then "reference" measures of activity (7-d activity recalls, pedometer readings) and fitness (treadmill test) were completed in subsets of this population.


RESULTS
The authors found that 7-d recall activity levels correlated well with the corresponding questionnaire indices among women (total activity, r = 0.65; vigorous, r = 0.85; moderate, r = 0.44; inactivity, r = 0.59; sleep duration, r = 0.52) and men (total activity, r = 0.51; vigorous, r = 0.65; moderate, r = 0.53; inactivity, r = 0.69; sleep duration, r = 0.39). Vigorous activity from 7-d recalls was best measured by gender-specific indices that included only recreational activities among men and emphasized nonrecreational activities among women. Correlations between questionnaire data and the other "reference" measures were lower. Test-retest correlations of questionnaire items over a 6-wk interval were high (r = 0.4-0.9).


CONCLUSIONS
Simple questions can measure activities of different intensity with good validity and reliability among black Adventist men and women.
Department of Epidemiology and Biostatistics, and Center for Health Research, Loma Linda University, School of Public Health, Loma Linda, CA 92350, USA. psingh@sph.llu.edu
P N
PN
Singh
G E
GE
Fraser
S F
SF
Knutsen
K D
KD
Lindsted
H W
HW
Bennett
D000328:Adult; D001741:Black or African American; D002835:Christianity; D015444:Exercise; D006801:Humans; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires