title: [Psychometric properties of a self-efficacy scale for physical activity in Brazilian adults].
abstract: 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 1,418 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.
authors: Universidade Estadual de Ponta Grossa, Curitiba, PR, Brasil.
authors: Cassiano Ricardo
authors: CR
authors: Rech
authors: Tais Taiana
authors: TT
authors: Sarabia
authors: Rogério César
authors: RC
authors: Fermino
authors: Pedro Curi
authors: PC
authors: Hallal
authors: Rodrigo Siqueira
authors: RS
authors: Reis