title: Mediation of effects of a theory-based behavioral intervention on self-reported physical activity in South African men.
abstract: OBJECTIVE
  Increasing physical activity is an important public-health goal worldwide, but there are few published mediation analyses of physical-activity interventions in low-to-middle-income countries like South Africa undergoing a health transition involving markedly increased mortality from non-communicable diseases. This article reports secondary analyses on the mediation of a theory-of-planned-behavior-based behavioral intervention that increased self-reported physical activity in a trial with 1181 men in Eastern Cape Province, South Africa.
  
  
  METHODS
  Twenty-two matched-pairs of neighborhoods were randomly selected. Within pairs, neighborhoods were randomized to a health-promotion intervention or an attention-matched control intervention with baseline, immediate-post, and 6- and 12-month post-intervention assessments. Theory-of-planned-behavior constructs measured immediately post-intervention were tested as potential mediators of the primary outcome, self-reported physical activity averaged over the 6- and 12-month post-intervention assessments, using a product-of-coefficients approach in a generalized-estimating-equations framework. Data were collected in 2007-2010.
  
  
  RESULTS
  Attitude, subjective norm, self-efficacy, and intention were significant mediators of intervention-induced increases in self-reported physical activity. The descriptive norm, not affected by the intervention, was not a mediator, but predicted increased self-reported physical activity.
  
  
  CONCLUSIONS
  The results suggest that interventions targeting theory-of-planned-behavior constructs may contribute to efforts to increase physical activity to reduce the burden of non-communicable diseases among South African men.
authors.affiliation: Department of Psychiatry, Perelman School of Medicine and Annenberg School for Communication, University of PA, USA. Electronic address: jjemmott@asc.upenn.edu.
authors.forename: John B
authors.initials: JB
authors.lastname: Jemmott
authors.affiliation: Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of PA, USA.
authors.forename: Alisa
authors.initials: A
authors.lastname: Stephens-Shields
authors.affiliation: National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, USA.
authors.forename: Ann
authors.initials: A
authors.lastname: O'Leary
authors.affiliation: School of Nursing, University of PA, USA.
authors.forename: Loretta Sweet
authors.initials: LS
authors.lastname: Jemmott
authors.affiliation: School of Nursing, University of PA, USA.
authors.forename: Anne
authors.initials: A
authors.lastname: Teitelman
authors.affiliation: Department of Anthropology, Haverford College, USA.
authors.forename: Zolani
authors.initials: Z
authors.lastname: Ngwane
authors.affiliation: Faculty of Education, University of Fort Hare, Alice, South Africa.
authors.forename: Xoliswa
authors.initials: X
authors.lastname: Mtose
mesh_terms: D000293:Adolescent; D000328:Adult; D001294:Attitude to Health; D015444:Exercise / Q000523:psychology*; D015438:Health Behavior; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D033182:Intention; D008297:Male; D008875:Middle Aged; D017008:Negotiating; D057566:Self Report; D066269:Social Theory; D013019:South Africa; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Cluster-randomized controlled trial; Intervention study; Mediation; Men; Physical activity; South Africa; Theory of planned behavior