Physical activity may be an important modifiable risk factor for many diseases. Studies examining physical activity - disease relationships must validly measure physical activity in order to produce meaningful results. Questionnaires are often the most feasible measurement tool, their validity being ascertained by comparison with criterion standard measures of physical activity. The purpose of this study is to examine the correlation between two common criterion measures of physical activity and to compare validation estimates of a past-year activity questionnaire when each is used as the criterion standard. Fifty-eight subjects were randomly selected from a total of 215 women aged 39-65 years participating in the Alumni Health Study. Baseline and one-year measures of physical activity were obtained using a modified version of the Historical Physical Activity Survey (HPAS). Subjects also completed quarterly 7-day physical activity logs (PAL) and wore an activity monitor (CSA accelerometer) corresponding to the fall PAL time period. Pearson correlations were used to examine the relationship between criterion measures of activity and to calculate validity estimates for the past-year activity questionnaire. Correlations between PAL and CSA measures of physical activity were .21 and .39 for moderate and total activity, respectively. Validity coefficients for the questionnaire were .09 using the CSA and .20 using the PAL. Results suggest a surprisingly poor correlation between two common criterion measures of activity. It is possible that the CSA and PAL measure different aspects of physical activity or that one or both of these measures have poor validity when used with certain populations.
Learning Objectives: At the conclusion of the presentation, the participant should be able to: 1. Identify three potential methods for measuring physical activity. 2. Recognize the importance of accurate measurement in physical activity epidemiology. 3. Describe the magnitude of the correlation between criterion measures of physical activity
Keywords: Physical Activity,
Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: None
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.