Traditional physical activity indexes derived from the Harvard alumni activity survey have low construct validity in a lower income, urban population.
The purpose of this study is to investigate the construct validity of the Harvard Alumni Activity Survey (HAAS) in an urban, lower income population. Data were collected from 192 smokers enrolled in an antioxidant micronutrient trial. Activity data were compared to body mass index (BMI), diastolic, and systolic blood pressure. The traditional physical activity index (PAI), using data on stair climbing, walking, and sports, was calculated including and excluding body mass. A new scale, the total weekly activity (TWA) scale, was derived from other questions on the HAAS. The PAI scale calculated with body mass was unassociated with BMI and blood pressure. The PAI scale calculated without body mass was unassociated with BMI and systolic blood pressure but was associated with diastolic blood pressure (Beta = -0.001, p = 0.03). The TWA scale was associated with BMI (Beta = -0.01, p = 0.01), diastolic (Beta = -0.03, p = 0.01), and systolic blood pressure (Beta = -0.04, p = 0.01). A one standard deviation change in the TWA scale is predicted to be equivalent to a change of 0.99 BMI units, 2.97 mmHg of diastolic blood pressure, and 3.96 mmHg of systolic blood pressure. This work suggests that the TWA scale has greater construct validity than the traditional PAI scale in this population.
Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY 10032, USA. agr3@columbia.edu
Andrew
A
Rundle
Marshall
M
Hagins
Manuela
M
Orjuela
Laverne
L
Mooney
Marty
M
Kim
Frederica
F
Perera
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001794:Blood Pressure; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness; D011203:Poverty / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012737:Sex Factors; D012907:Smoking; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014505:Urban Population / Q000706:statistics & numerical data*