Smartphone apps help kids to be more active

Smartphone-based interventions, such as apps and text messaging, helps promote exercise among kids and teens, according to a new meta-analysis.

“The findings of this meta-analysis indicated that interventions based on smartphone may be a promising strategy to increase the number of steps and total physical activity (TPA) of children and adolescents,” the researchers said, noting that the impact on moderate-to-vigorous PA (MVPA) remains to be seen.

From an initial pool of 3,263 studies retrieved from online databases, nine studies were eligible for inclusion in the analysis. Of these, four assessed app interventions, three looked at short messaging services (SMS), and two employed a combination. Together, the studies yielded a sample of 558 participants, with an average age of 13.2 years.

Overall, smartphone-based interventions led a significant improvement in PA relative to controls (standardized mean difference [SMD], 0.44, 95 percent confidence interval [CI], 0.11–0.77; p=0.009). [JMIR Mhealth Uhealth 2021;9:e22601]

However, heterogeneity of evidence was high and significant (p<0.001), and meta-regression analysis identified duration as a potential explanation for such heterogeneity, prompting subsequent subgroup analyses.

Stratifying participants according to intervention revealed that apps could significantly improve PA among children and adolescents (SMD, 0.76, 95 percent CI, 0.23–1.30), whereas SMS could not (SMD, 0.18, 95 percent CI, –0.06 to 0.42). Similarly, interventions lasting for ≤8 weeks were effective (SMD, 0.76, 95 percent CI, 0.23–1.30), while those extending beyond were not (SMD, 0.14, 95 percent CI, –0.07 to 0.36).

“The advantage of apps lies in their convenience and novelty. Through the app, you can receive feedback in real time, communicate, and self-monitor, among other possibilities,” the researchers said, adding that the impact of shorter-term interventions “may be attributed to the curiosity of the participants in the early stages of the intervention, and that they are willing to participate in the implementation.”

“Over time, the decline in the interest and compliance of the participants led to the intervention effect not being maintained,” they said.

The effectiveness of smartphone-based interventions was also significant when measured objectively (SMD, 0.50, 95 percent CI, 0.09–0.91), rather than subjectively (SMD, 0.22, 95 percent CI, –0.08 to 0.51).

Children (SMD, 0.64, 95 percent CI, 0.10–1.18) also stood to gain more from such interventions, as opposed to adolescents (SMD, 0.32, 95 percent CI, –0.12 to 0.75).

Notably, the interventions were only effective when looking at the participants’ TPA (weighted mean difference [WMD], 32.35, 95 percent CI, 10.36–54.33) and number of steps (WMD, 1,185, 95 percent CI, 303–2,068), but not when considering MVPA (WMD, 3.91, 95 percent CI, –1.99 to 9.81).

“To extend the promise of smartphone intervention, [there is a need for] comparative trials among different smartphone technologies,” the researchers said. “Moreover, additional studies are needed to determine the effects on different participants, such as for children who are overweight and obese, and low-income people.”