JMIR Publications

ABSTRACT

Background:

Smartphone apps are a promising tool for delivering accessible and appealing physical activity interventions.

Objective:

This systematic review and meta-analysis aimed to determine the effectiveness of smartphone apps for increasing objectively measured physical activity in adults.

Methods:

Seven electronic databases (Embase, Emcare, Medline, Scopus, Sport Discus, The Cochrane Library and Web of Science) were searched from 2007 to January 2018. Following the PICOS format, studies were eligible if they were randomised-controlled trials involving adults, used a smartphone app as the primary or stand-alone component of the physical activity intervention, used a no or minimal intervention control condition, and measured objective physical activity either in the form of minutes of moderate to vigorous physical activity (MVPA) or steps. Study quality was assessed using a 25-item tool based on the CONSORT Checklist. A meta-analysis of study effects was conducted using a random-effects model approach. Sensitivity analyses were conducted to examine whether intervention effectiveness differed on the basis of intervention length, target behaviour (physical activity alone, vs physical activity in combination with other health behaviours) or target population (general adult population vs specific health populations).

Results:

Following the removal of duplicates, a total of 6170 studies were identified from the original database search. Nine studies, involving a total of 1740 participants, were identified as meeting eligibility criteria for inclusion in this review. Of these, six studies could be included in a meta-analysis of the effects of physical activity apps on steps/day. In comparison to the control conditions, smartphone apps produced a non-significant (P = .19) increase in participants’ average steps per day, with mean difference between groups of 476.75 steps/day (95% CI = -229.57 to 1183.07). Sensitivity analyses suggested that physical activity programs with a duration < 3 months were more effective than apps evaluated across > 3 months (P = .01) and that physical activity apps that targeted physical activity in isolation were more effective than apps that targeted physical activity in combination with diet (P = .04). Physical activity app effectiveness did not appear to differ on the basis of target population.

Conclusions:

This meta-analysis provides modest evidence supporting the effectiveness of smartphone apps to increase physical activity. To date, apps have been most effective in the short term (e.g. up to 3 months). Future research is needed to understand the time course of intervention effects and to investigate strategies to sustain intervention effects over time.