Digital Health Nudging to increase physical activity in pediatric patients with congenital heart disease: A randomized controlled trial.

Background: Digital nudging is a modern e-health approach to increase physical activity (PA) in younger age groups. As activity promotion is particularly important in adolescents with congenital heart disease (CHD) this randomized-controlled trail examines if Digital Health Nudging via daily smartphone messages increases PA, activity-related self-efficacy (ArSE) and health-related quality of life (HrQoL) in adolescents with CHD.

Methods: From May 2021 to April 2022, 97 patients (15.1 ± 2.0 years, 50% girls) with moderate or severe CHD were randomly allocated 1:1 to intervention (IG) or control group (CG). Daily PA was objectively assessed in minutes of moderate-to-vigorous PA (MVPA) by the wearable "Garmin Vivofit jr. 2" over the entire study period. The IG received daily smartphone messages based on Bandura's social cognitive theory on the subject of PA over a period of 12-weeks.

Results: According to the linear mixed model, the change of MVPA over the study period did not significantly differ between IG and CG when taking baseline MVPA into account (b = 0.136, 95%-CI [-0.355; 0.627], P = .587). Activity level was comparably high and showed only minor variability in both groups with 73.7 [62.3; 78.8] min/day in IG and 78.4 [66.6; 93.9] min/d in CG throughout the whole 12-weeks. Emotional well-being significantly increased over the study period in the IG (IG: Δ1.60 [-0.2; 6.3] vs CG: Δ0.0 [-12.5; 6.3], P = .043), but not total HrQoL (P = .518) and ArSE (P = .305).

Conclusions: 12-weeks, of Digital Health Nudging did not increase PA, but improved feelings of emotional well-being in adolescents with CHD.

Trial Registration: Clinical Trials Identifier NCT04933786.