A recent systematic review sought to determine the effect of interventions using activity trackers on physical activity levels and mobility compared with usual care or another physical activity intervention in older people. The review searched eight databases to identify randomised controlled trials involving participants aged 60 years and older. Trials enrolling healthy older adults or older adults with health conditions were eligible. The primary outcome was physical activity quantified as steps per day and measured using an activity tracker or accelerometer. Other types of objective measures of physical activity (e.g., time in moderate-to-vigorous physical activity) or self-reported physical activity measures were excluded. Secondary outcomes included mobility. The methodological quality of the trials was measured with the PEDro scale. The quality of the evidence was assessed with the GRADE approach.

Twenty-three randomised trials including 2,766 participants, with publication dates ranging from 2003 to 2017, were included in the review. There is low quality evidence that participants allocated to activity tracker interventions increased their physical activity levels by 1,558 steps per day (95% confidence interval (CI) 1,099 to 2,018) more than control participants after the intervention. At 12 months post-intervention, the differences between activity tracker and control interventions were not sustained (1 trial, 571 participants; mean difference 210 steps 95% CI -148 to 567). There was moderate quality evidence that activity tracker interventions improved mobility compared to control interventions (3 trials, 218 participants, standardised mean difference 0.61, 95% CI 0.31 to 0.90). Meta-regression did not find any differences in physical activity levels between: trials conducted in healthy populations (9 trials, standardised mean difference 0.61, 95% CI 0.25 to 0.96) versus populations with health conditions (14 trials, standardised mean difference 0.54, 95% CI 0.25 to 0.82)); trials using accelerometers (7 trials, standardised mean difference 0.24; 95% CI -0.15 to 0.63) versus trials using pedometers (16 trials, standardised mean difference 0.69; 95% CI 0.45 to 0.93); or trials with small (< 100 participants) sample sizes (15 trials, standardised mean difference 0.72; 95% CI 0.42 to 1.01) versus large sample sizes (8 trials, standardised mean difference 0.40; 95% CI 0.10 to 0.70). In contrast, a significant interaction between intervention duration and effect size was found, with longer interventions (12 or more weeks) having a larger impact on increasing physical activity levels (18 trials, standardised mean difference 0.70, 95% CI 0.47 to 0.93) compared to shorter interventions (5 trials, standardised mean difference 0.14; 95% CI -0.26 to 0.54).

Oliveira JS, et al. Effect of interventions using physical activity trackers on physical activity in people aged 60 years and over: a systematic review and meta-analysis. Br J Sports Med 2019 Aug 9:Epub ahead of print

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