[Reliability and validity of a 7-day physical activity questionnaire for elementary students]

Area of Science:

• Pediatric epidemiology
• Physical activity assessment
• Childhood health research

Background:

• Accurate measurement of physical activity is crucial for understanding children's health.
• Existing questionnaires may have limitations in capturing recent physical activity patterns.
• Developing reliable tools is essential for large-scale epidemiologic studies.

Purpose of the Study:

• To evaluate the reliability and validity of a 7-day physical activity questionnaire.
• To assess its utility in epidemiologic studies involving 4th-6th grade children.
• To determine if the questionnaire provides accurate physical activity data for this age group.

Main Methods:

• A 7-day physical activity questionnaire was developed using focus groups, observation, and expert consultation.
• Test-retest reliability was assessed over two weeks in 92 children (4th-6th grade).
• Validity was evaluated against expert assessment and the Caltrac motion sensor.

Main Results:

• The questionnaire demonstrated good test-retest agreement (Kappa: 0.46-0.79; Spearman correlations: 0.66-0.87 for boys, 0.57-0.82 for girls).
• Experts confirmed good face and content validity.
• No significant difference was found between questionnaire and Caltrac sensor data; significant correlations (r=0.46, 0.38) were observed for boys.

Conclusions:

• The 7-day physical activity questionnaire provides a reliable estimate of recent physical activity in 4th-6th grade children.
• The questionnaire offers a valid estimation of physical activity for boys in this age range.
• This tool is suitable for use in epidemiologic studies focusing on childhood physical activity.