Psychometric validation of the belief-based physical activity questionnaire

Area of Science:

• Health Psychology
• Behavioral Science
• Sociology

Background:

• Physical activity (PA) is crucial for health, yet adoption rates vary significantly across demographics.
• Understanding psychosocial determinants of PA is essential for targeted health interventions, particularly among young women in Saudi Arabia.

Purpose of the Study:

• To develop and validate the belief-based physical activity questionnaire for young Saudi females (BPAQ-YSF).
• To assess the psychometric properties of the questionnaire and its utility in understanding the Theory of Planned Behavior (TPB) constructs related to PA.

Main Methods:

• Conceptual and content validity were established through expert reviews (n=14).
• Cross-sectional validation involved 820 Saudi females (aged 18-35) using a test-retest design.
• Psychometric properties were assessed using adopted scales, Cronbach's alpha, and principal axis factoring (PAF) for an 8-factor extended TPB model.

Main Results:

• The BPAQ-YSF demonstrated reliable psychometric properties suitable for cross-cultural application.
• Principal axis factoring identified an 8-factor structure explaining 76.6% of the variance in the extended TPB.
• Cronbach's alpha values confirmed the reliability of the adopted scales.

Conclusions:

• The BPAQ-YSF is a valid and reliable instrument for assessing psychosocial factors influencing physical activity in young Saudi women.
• The findings support the application of the extended TPB in this population and can inform culturally tailored PA interventions.