Revista Panamericana de Salud Pública
On-line version ISSN 1680-5348
Print version ISSN 1020-4989
RECH, Cassiano Ricardo et al. Psychometric properties of a self-efficacy scale for physical activity in Brazilian adults. Rev Panam Salud Publica [online]. 2011, vol.29, n.4, pp.259-266. ISSN 1680-5348. http://dx.doi.org/10.1590/S1020-49892011000400007.
OBJECTIVE: To test the validity and reliability of a self-efficacy scale for physical activity (PA) in Brazilian adults. METHODS: A self-efficacy scale was applied jointly with a multidimensional questionnaire through face-to-face interviews with 1418 individuals (63.4% women) aged > 18 years. The scale was submitted to validity (factorial and construct) and reliability analysis (internal consistency and temporal stability). A test-retest procedure was conducted with 74 individuals to evaluate temporal stability. RESULTS: Exploratory factor analyses revealed two independent factors: self-efficacy for walking and self-efficacy for moderate and vigorous PA (MVPA). Together, these two factors explained 65.4% of the total variance of the scale (20.9% and 44.5% for walking and MVPA, respectively). Cronbach's alpha values were 0.83 for walking and 0.90 for MVPA, indicating high internal consistency. Both factors were significantly and positively correlated (rho > 0.17, P < 0.001) with quality of life indicators (health perception, self-satisfaction, and energy for daily activities), indicating an adequate construct validity. CONCLUSIONS: The scale's validity, internal consistency, and reliability were adequate to evaluate self-efficacy for PA in Brazilian adults.
Keywords : Motor Activity; exercise; psychometrics; self-efficacy; Brazil.