Long-Term Effectiveness of a Smartphone App for Improving Healthy Lifestyles in General Population in Primary Care: Randomized Controlled Trial (Evident II Study)

Background: Information and communication technologies are currently among the supporting elements that may contribute to improving health and changing lifestyles.

Objective: The aim of this study was to evaluate the long-term effectiveness of adding an app to standardized counseling in order to increase physical activity (PA) and adherence to the Mediterranean diet and to analyze the effects of app adherence in lifestyle changes.

Methods: A randomized, multicenter clinical trial with a 12 month-follow up was conducted, involving 833 participants recruited by random sampling in 6 primary Spanish care centers (415 vs 418). Counseling on PA and the Mediterranean diet was given to both groups by a research nurse; however, the counseling + app group (intervention group) received additional training in the use of an app that was designed to promote the Mediterranean diet and PA over a 3-month period. Main outcomes and measures included PA by accelerometer and the 7-day Physical Activity Recall (PAR) questionnaire and adherence to the Mediterranean diet by an adherence screener questionnaire. We considered adherence to the app to be high when it was used for more than 60 days.

Results: The mean age was 51 years (SD 12) in the intervention group and 52.3 years (SD 12.0) in the counseling-only group; females predominated in both groups (60.0%, 249/415 and 64.1%, 268/418, respectively). PA by accelerometer declined in both groups at 12 months (P value for tendency in moderate to vigorous PA, [MVPA]=.15). The intervention subgroup with high app adherence had better behavior than the low adherence subgroup (P value for tendency in MVPA=.001). PA analyzed by 7-day PAR did not show changes at 12 months in any of the groups (P value for tendency=.25). In the Mediterranean diet, an increase in adherence was observed in both groups at 12 months with no differences between them (P value for tendency=.46). In these two cases, the group with high app adherence also had better behavior, although without reaching significance for the tendency (P>.05).

Conclusions: The participants with strongest app adherence showed better outcomes in terms of maintenance of healthy lifestyles at 12 months than those with weaker adherence. Overall, however, we found no differences between intervention group and counseling-only group in PA increase and adherence to the Mediterranean diet in the long term.