title: Reliability and Validity of the Commitment to Physical Activity Scale for Adolescents.
abstract: OBJECTIVE
  To examine psychometric properties of a Commitment to Physical Activity Scale for Adolescents (CPASA).
  
  
  METHODS
  Two test-retest studies and a prospective study, approved by a university institutional review board, were conducted in midwestern U.S. urban areas.
  
  
  METHODS
  The first test-retest study occurred in four community centers, the second test-retest study took place in a community school, and the prospective study occurred in eight middle schools.
  
  
  METHODS
  To measure commitment at baseline and 1 week later, 51 girls in the first test-retest study completed an original 26-item scale, and 91 in the second test-retest study completed a revised 11-item scale. In the prospective study, 503 girls completed the 11-item scale.
  
  
  METHODS
  Commitment was measured via the CPASA. After completing the CPASA, girls in the prospective study wore ActiGraph GT3X-plus accelerometers that measured light, moderate, and vigorous physical activity (LMVPA) and moderate to vigorous physical activity (MVPA).
  
  
  METHODS
  Internal consistency and test-retest reliability were estimated. Both exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were conducted to cross-validate the factor structure.
  
  
  RESULTS
  For the 11-item CPASA, Cronbach α ranged from .81 to .82, and test-retest reliability was .88. Both EFA and CFA indicated a single factor. The scale was significantly correlated with LMVPA (r = .10) and MVPA (r = .11).
  
  
  CONCLUSIONS
  The 11-item CPASA demonstrated acceptable reliability and validity with girls.
authors.affiliation: 1 Michigan State University College of Nursing, East Lansing, Michigan.
authors.forename: Lorraine B
authors.initials: LB
authors.lastname: Robbins
authors.affiliation: 1 Michigan State University College of Nursing, East Lansing, Michigan.
authors.forename: Jiying
authors.initials: J
authors.lastname: Ling
authors.affiliation: 1 Michigan State University College of Nursing, East Lansing, Michigan.
authors.forename: Stacey M
authors.initials: SM
authors.lastname: Wesolek
authors.affiliation: 1 Michigan State University College of Nursing, East Lansing, Michigan.
authors.forename: Anamaria S
authors.initials: AS
authors.lastname: Kazanis
authors.affiliation: 1 Michigan State University College of Nursing, East Lansing, Michigan.
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Bourne
authors.affiliation: 2 University of Michigan School of Public Health, Ann Arbor, Michigan.
authors.forename: Ken
authors.initials: K
authors.lastname: Resnicow
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D015444:Exercise / Q000523:psychology*; D005163:Factor Analysis, Statistical; D005260:Female; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D008297:Male; D010465:Perception; D011446:Prospective Studies; D011594:Psychometrics; D015203:Reproducibility of Results; D020377:Self Efficacy; D012959:Socioeconomic Factors
keywords: Female, Exercise, Adolescent, Motivation, Factor analysis, Measures, Prevention Research. Manuscript format: research; Health focus: fitness/physical activity; Outcome measure: cognitive and behavioral; Research purpose: instrument development; Setting: local community and schools; Strategy: skill development/behavior change; Study design: nonexperimental; Target population age: youth; Target population circumstances: education/income level, geographic location, race-ethnicity