JMIR Publications

ABSTRACT

Background:

Although mobile phone-based interventions (mHealth) have demonstrated effectiveness in modifying one or two health risk behaviors at a time, there is a knowledge gap regarding the effects of stand-alone mHealth interventions on multiple health risk behaviors.

Objective:

To estimate the effectiveness of an mHealth intervention (LIFE4YOUth) targeting alcohol, diet, physical activity, and smoking among Swedish high school students.

Methods:

A 2-arm parallel group, single-blind randomized controlled trial (1:1) was conducted from 2020 to 2023 to estimate the 2- and 4-month effectiveness of LIFE4YOUth compared with a waiting-list control group on high school students’ health risk behaviors. Paper and digital advertisement were used to recruit students from high schools in Sweden, covering north, middle and southern areas. Students (n = 756) aged 15-20 years (mean 17.1, SD 1.2; 69% females, 31% males) who met the eligibility criteria of not adhering to ≥1 of 6 guidelines related to the outcomes were included in the trial. All participants received a hyperlink to general health information. The intervention group additionally had 4-month access to LIFE4YOUth: a fully automated intervention including recurring screening, text message services, and an online interactive dashboard. Effects were estimated through self-reported data on weekly alcohol consumption, heavy episodic drinking, fruit and vegetables consumption, sugary drinks consumption, moderate to vigorous physical activity, and smoking cessation.

Results:

In total, 69% and 54% responded to the 2- and 4-month follow-up survey. The intention-to-treat analysis showed similar results from imputed and complete case data. At 2 months, the between-group differences were 0.32 portions/day of fruit and vegetable consumption (95% CI = 0.13; 0.53, probability of effect = 99.9%, P=.001), 50 min/week of physical activity (95% CI = -0.19; 99.73, probability of effect = 97.4%, P=.05), and an incidence rate ratio for heavy episodic drinking of 0.77 (95% CI = 0.55; 1.07, probability of effect = 93.6%, P=.14). At 4 months, a remaining effect was observed on physical activity only. There was no evidence of an effect on smoking. Fifty-eight percent (n = 219) of participants in the intervention group engaged with the LIFE4YOUth intervention at least once.

Conclusions:

The LIFE4YOUth intervention had a modest short-term effect primarily on physical activity and fruit and vegetable consumption. Our results align with previous research on mHealth, suggesting that a multiple behavior approach shows potential in addressing physical inactivity and unhealthy diets, but may not effectively influence adolescents’ alcohol consumption and smoking behaviors.

Conclusions:

The LIFE4YOUth intervention had a modest short-term effect primarily on physical activity and fruit and vegetable consumption. Our results align with previous research on mHealth, suggesting that a multiple behavior approach shows potential in addressing physical inactivity and unhealthy diets, but may not effectively influence adolescents’ alcohol consumption and smoking behaviors. Clinical Trial: ISRCTN (ISRCTN34468623)