Efficacy of theory-informed workplace physical activity interventions: a systematic literature review with meta-analyses.

This review aimed to assess the efficacy of workplace physical activity interventions; compare the efficacy of those that were and were not informed by behaviour change theory, and outline the effectiveness of different intervention components. A search was undertaken in Medline, Embase, PsycINFO, Ovid Emcare (previously CINAHL) and SportDiscus. Randomised, non-randomised and cluster-controlled trials with objectively measured physical activity and/or measured or predicted maximal oxygen uptake (VO_2max) as outcomes were included in the review (83 papers from 79 trials). Random-effects meta-analyses of mean differences were undertaken. Workplace physical activity programmes demonstrated positive overall intervention effects for daily step counts (814.01 steps/day; CI: 446.36, 1181.67; p < 0.01; i² = 88%) and measured VO_2max (2.53 ml kg^-1 min^-1; CI: 1.69, 3.36; p < 0.01; i² = 0%) with no sub-group differences between theory- and non-theory informed interventions. Significant sub-group differences were present for predicted VO_2max (p < 0.01), with a positive intervention effect for non-theory informed studies (2.11 ml.kg^-1 min^-1; CI: 1.20, 3.02; p < 0.01; i² = 78%) but not theory-informed studies (-0.63 ml kg^-1 min^-1; CI: -1.55, 0.30; p = 0.18; i² = 0%). Longer-term follow-ups ranged from 24 weeks to 13 years, with significant positive effects for measured VO_2max (2.84 ml kg^-1 min^-1; CI: 1.41, 4.27; p < 0.01; i² = 0%). Effective intervention components included the combination of self-monitoring with a goal, and exercise sessions onsite or nearby. The findings of this review were limited by the number and quality of theory-informed studies presenting some outcomes, and confounding issues in complex interventions. Future researchers should consider rigorous testing of outcomes of theory-informed workplace physical activity interventions and incorporate longer follow-ups.