The validity of single-item, self-assessment questions as measures of adult physical activity.
Individual energy expenditure (kcal/kg/day) was calculated from a detailed set of questions from the Health Promotion and Disease Prevention Supplement of the 1985 National Health Interview Survey. Responses to three single-item, self-assessment questions were compared to the energy expenditure variable to test criterion validity. Spearman's correlation coefficient revealed moderate correlations between energy expenditure and corresponding levels of self-assessed leisure-time physical activity for each single-item question (r = 0.14 to 0.41). For purposes of measuring prevalence of physical activity, the energy expenditure variable was used to categorize individuals into activity levels. The single-item questions were found to have Spearman's correlations with the categorical measures ranging from 0.11 to 0.37 for leisure-time activities. Generally higher correlations were found for males and younger age groups (18-34 years). The relationships were interpreted as being weak relative to an expected correlation of 0.75 for criterion validation. However, the single-item questions show promise for obtaining proxy estimates of the degree of leisure-time physical activity in a population.
Weiss
T W
TW
University of Texas Health Sciences Center, School of Public Health, Houston 77225.
Slater
C H
CH
Green
L W
LW
Kennedy
V C
VC
Albright
D L
DL
Wun
C C
CC
D000328:Adult; D000367:Age Factors; D000368:Aged; D004734:Energy Metabolism; D015444:Exercise; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012737:Sex Factors; D011795:Surveys and Questionnaires / Q000592:standards*; D014937:Work / Q000502:physiology*