Effectiveness of remote feedback on physical activity in persons with type 2 diabetes: A systematic review and meta-analysis of randomized controlled trials

Objectives The objective of this systematic review and meta-analysis was to examine the effectiveness of remote feedback intervention compared with standardized treatment on physical activity levels in persons with type 2 diabetes. Further, to investigate the influence of the length of intervention, number of contacts, study size, delivery of feedback, and preliminary face-to-face sessions. Methods A systematic literature search was conducted in May 2017, with a priori defined eligibility criteria: randomized controlled trials investigating remote feedback interventions in adult persons with type 2 diabetes, using physical activity as outcome. The effect size was calculated as standardized mean difference (SMD) and was pooled in a meta-analysis using a random-effects model. Meta-regression analyses were performed to examine if the observed effect size could be attributed to study- or intervention characteristics using these as covariates. Results The literature search identified 4455 articles of which 27 met the eligibility criteria. The meta-analysis including a total of 4215 participants found an overall effect size in favour of remote feedback interventions compared to standardized treatment, SMD = 0.33 (95% CI: 0.17 to 0.49), I2 = 81.7%). Analyses on study characteristics found that the effect on physical activity was only influenced by study size, with a larger effect in small studies. Conclusion Adding remote feedback to standardized treatments aimed at increasing physical activity in persons with type 2 diabetes showed a small to moderate additional increase in physical activity levels. Systematic review registration: PROSPERO CRD42016033479.