Validity and reproducibility of self-reported total physical activity--differences by relative weight

Area of Science:

• Epidemiology
• Public Health
• Exercise Science

Background:

• Physical activity is linked to reduced chronic disease risk and increased longevity.
• Existing questionnaires often capture only partial physical activity, leading to potential misclassification.
• Accurate measurement of total daily physical activity is crucial for reliable health risk assessment.

Purpose of the Study:

• To evaluate the validity and reproducibility of a brief, self-administered questionnaire.
• To assess the questionnaire's ability to measure long-term total daily 24-hour physical activity.
• To determine if the questionnaire can accurately estimate physical activity levels in men.

Main Methods:

• A questionnaire assessing occupational, household, leisure-time activity, and sleep was administered twice to 111 men (aged 44-78).
• Physical activity was measured in metabolic equivalents (MET)xh/day.
• Validity was assessed against two 7-day activity records, with reproducibility assessed between questionnaire administrations.

Main Results:

• The Spearman correlation coefficient for validity (questionnaire vs. records) was 0.56 (deattenuated).
• Reproducibility between the two questionnaire administrations was 0.65.
• Higher validity was found in men with a body mass index below 26 kg/m² (r=0.73) compared to heavier men (r=0.39).

Conclusions:

• The self-administered questionnaire provides satisfactory estimation of average total daily physical activity in men.
• This tool can aid in more accurate assessment of physical activity in population studies.
• Further research may explore its utility in diverse populations and its impact on disease risk estimation.