Laranjo, LilianaDing, DingHeleno, BrunoKocaballi, BakiQuiroz, Juan CTong, Huong LyChahwan, BahiaNeves, Ana LuisaGabarron, EliaDao, Kim PhuongRodrigues, DavidNeves, Gisela CostaAntunes, Maria Da LuzCoiera, EnricoBates, David W2020-12-262020-12-262021-04Laranjo L, Ding D, Heleno B, Kocaballi B, Quiroz JC, Antunes ML, et al. Do smartphone applications and activity trackers increase physical activity in adults? Systematic review, meta-analysis and metaregression. Br J Sports Med. 2021;55(8):422-32.http://hdl.handle.net/10400.21/12519Objective: To determine the effectiveness of physical activity interventions involving mobile applications (apps) or trackers with automated and continuous self-monitoring and feedback. Design: Systematic review and meta-analysis. Data sources: PubMed and seven additional databases, from 2007 to 2020. Study selection: Randomised controlled trials in adults (18-65 years old) without chronic illness, testing a mobile app or an activity tracker, with any comparison, where the main outcome was a physical activity measure. Independent screening was conducted. Data extraction and synthesis: We conducted a random-effects meta-analysis and all effect sizes were transformed into a standardized difference in means (SDM). We conducted exploratory metaregression with continuous and discrete moderators identified as statistically significant in subgroup analyses. Main outcome measures: Physical activity: daily step counts, min/week of moderate-to-vigorous physical activity, weekly days exercised, min/week of total physical activity, metabolic equivalents. Results: Thirty-five studies met inclusion criteria and 28 were included in the meta-analysis (n=7454 participants, 28% women). The meta-analysis showed a small-to-moderate positive effect on physical activity measures (SDM 0.350, 95% CI 0.236 to 0.465, I2=69%, T 2=0.051) corresponding to 1850 steps per day (95% CI 1247 to 2457). Interventions including text-messaging and personalization features were significantly more effective in subgroup analyses and metaregression. Conclusion: Interventions using apps or trackers seem to be effective in promoting physical activity. Longer studies are needed to assess the impact of different intervention components on long-term engagement and effectiveness.engAccelerometerAppBehaviourEffectivenessPhysical activityjournal article10.1136/bjsports-2020-102892