title: Meta-analysis of quality-of-life outcomes from physical activity interventions.
abstract: BACKGROUND
  Interventions to increase physical activity among adults with chronic illness are intended to improve quality of life and reduce disease complications or slow disease progression.
  
  
  OBJECTIVE
  The aim of this study was to integrate quality-of-life outcomes from primary research studies testing interventions to increase physical activity among adults with chronic illness.
  
  
  METHODS
  Extensive literature searching strategies were used to locate published and unpublished primary research testing physical activity interventions. Results were coded for studies that had at least 5 participants with chronic illness. Fixed- and random-effects meta-analytic procedures included moderator analyses.
  
  
  RESULTS
  Eighty-five samples from 66 reports with 7,291 subjects were synthesized. The mean quality-of-life effect size for two-group comparisons (treatment vs. control) was.11 (higher mean quality-of-life scores for treatment subjects than for control subjects). The treatment group pre-post comparison effect size was.27 for quality of life. Heterogeneity was modest in two-group comparisons. Most design and sample attributes were unrelated to intervention effects on quality of life. Studies that exclusively used supervised center-based exercise reported larger quality-of-life improvements than did studies that included any educational/motivational content. Effect sizes were larger among unpublished and unfunded studies. The effect size for physical activity did not predict the quality-of-life effect size.
  
  
  CONCLUSIONS
  Subjects experience improved quality of life from exposure to interventions designed to increase physical activity, despite considerable heterogeneity in the magnitude of the effect. Future primary research should include quality-of-life outcomes so that patterns of relationships among variables can be explored further.
authors.affiliation: School of Nursing, University of Missouri, Columbia, MO 65211, USA. conn@missouri.edu
authors.forename: Vicki S
authors.initials: VS
authors.lastname: Conn
authors.forename: Adam R
authors.initials: AR
authors.lastname: Hafdahl
authors.forename: Lori M
authors.initials: LM
authors.lastname: Brown
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001294:Attitude to Health; D002908:Chronic Disease / Q000517:prevention & control / Q000523:psychology; D003627:Data Interpretation, Statistical; D015987:Effect Modifier, Epidemiologic; D015444:Exercise / Q000523:psychology*; D005081:Exercise Therapy / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010549:Personal Satisfaction; D011788:Quality of Life / Q000523:psychology; D012044:Regression Analysis; D012106:Research; D012648:Self Care / Q000379:methods / Q000523:psychology; D016896:Treatment Outcome