Sandra A. Ham, Caroline A. Macera, Deborah A. Jones, Barbara E. Ainsworth and Kathleen M. Turczyn
To explore among demographic groups the differences in prevalence estimates of physical activity that may occur as a result of differences in survey design characteristics, including question wording, placement, and examples of activities.
We compared responses to similar physical activity instruments administered to large samples of adults in 1999 (n = 9,775), 2000 (n = 32,374), and 1999–2000 (n = 7,529). The questions assessed participation in non-occupational physical activity at vigorous and moderate intensities. Surveys used in-person or telephone interviews.
The prevalence of recommended levels of physical activity (i.e., ≥3 days and ≥20 min vigorous activities or ≥5 days and ≥30 min moderate activities) varied 10% across 3 surveys. Although survey design characteristics varied, higher prevalence was associated with the use of examples to measure multiple domains of activity and question order.
Measuring multiple domains is important for assessing health-related physical activity. These results suggest that physical activity measurement varies with question and survey design characteristics.
Diana L. Jones, Deborah Tannehill, Mary O’Sullivan and Sandra A. Stroot
Michelle M. Yore, Sandra A. Ham, Barbara E. Ainsworth, Caroline A. Macera, Deborah A. Jones and Harold W. Kohl III
In 2001, the Behavioral Risk Factor Surveillance System (BRFSS) included a new occupational physical activity (PA) question. This article evaluates the reliability of this survey question.
Forty-six subjects were followed for 3 wk, answered 3 PA surveys by telephone, and completed daily PA logs for 1 wk. Kappa statistics determined the reliability of occupational activities (sitting/standing, walking, and heavy lifting). A descriptive analysis compared the time in specific occupational activities.
Eighty percent of the respondents reported “mostly sitting or standing” at work; and test–retest reliability was moderate (k = 0.40 to 0.45). The occupationally inactive sat/stood for 85% (mean hours = 5.6) of the workday, whereas the occupationally active sat/stood for 53% (mean hours = 3.9) of the workday.
The BRFSS occupational activity question has moderate reliability, distinguishes between occupationally active and inactive persons, and can be used in surveillance systems to estimate adult occupational PA.