Evaluating the Impact of the StandUPTV Intervention on Proximal Mediators and Self-reported Outcomes

Recreational sedentary screen time (rSST) is associated with increased risk for cancer, cardiovascular disease, diabetes, and all-cause mortality, but there is a lack of efficacious interventions to reduce rSST among adults. The StandUPTV mHealth intervention was developed to determine the best strategies to reduce rSST in adults, and using a 23 full factorial trial, achieved a significant reduction in rSST by an average of 75 minutes per day over a 16-week period. PURPOSE: The purpose of the present study is to examine changes in social cognitive theory (SCT) derived mediators (e.g., self-efficacy outcome expectations and motivation), rSST-related habits, and self-reported health outcomes (e.g., sleep, SF-12) among participants in the StandUPTV trial. METHODS: Eligible participants provided informed consent and completed 11 questionnaires through the REDCap platform at three assessment timepoints (baseline, 8, and 16 weeks). Linear mixed effects models were used to assess changes in scores at baseline, 8 weeks, and 16 weeks for each survey. RESULTS: Participants (N=110) had a mean age of 41 (11.7) y and BMI of 29.7 (7.8) kg/m2 at baseline. At baseline compared to 16 weeks, there were significant decreases in screen time self-efficacy scores (53.8 [2.5] vs 47.5 [2.8], p<0.05) and motivation (20.3 [0.41] vs 18.2 [0.46], p<0.001), and became more conscious of screen usage (16.9 [0.39] vs 14.7 [0.44], p<0.001). Overall sleep quality improved from baseline to 16-weeks (7.5 [0.31] vs 6.7 [0.33], p<0.001) and improvements in mental function (39.5 [0.70] to 40.6 [0.79], p<0.001). CONCLUSION: These findings indicate that StandUPTV increased awareness of rSST behaviors. Interestingly, scores for SCT-related mediators did not change significantly, except for motivation and self-efficacy which worsened. Future research is needed to understand if different intervention strategies differentially impact proximal mediators and reductions in rSST. The intervention to reduce rSST did result in improvements in sleep quality and mental but not physical function.