Developing A Scale for Factors Influencing The Physical Activity of Students at The University of Danang, Vietnam, Based on The Theoretical Domains Framework

Introduction: University students' physical activity is influenced by various personal, social, and environmental factors. However, there is currently no standardized scale in Vietnam based on the Theoretical Domains Framework (TDF) to comprehensively assess these factors. This study aimed to develop and preliminarily test the reliability of a scale measuring factors influencing the physical activity of students at the University of Danang, based on the TDF. 

Methods: A methodological study was conducted in three stages: (1) a literature review to develop an initial set of items based on the 14 domains of the TDF; (2) content validity assessment through two rounds of interviews with 15 experts; and (3) reliability testing using Cronbach’s alpha with 400 students from two-member universities of the University of Danang. Data were analyzed using SPSS 22.0 software. 

Results: From an initial set of 65 criteria, the study selected 51 criteria that achieved a consensus level exceeding 75%, representing the 14 domains of the TDF. Reliability analysis showed that Cronbach’s Alpha coefficients for the domains ranged from 0.706 to 0.916; furthermore, all observed variables exhibited item-total correlation coefficients greater than 0.30, confirming the scale's reliability and internal consistency. 

Conclusion: The 51-item scale, covering the 14 TDF domains, demonstrates good reliability and serves as a scientifically grounded tool for assessing factors influencing the physical activity of university students. These findings provide a foundation for future research aimed at validating the scale's structural validity and designing intervention programs to enhance physical activity within Vietnamese universities.