Table 4.

Study characteristics for the use of tailored text/phone calls.

Year/Study	Participants	Digital Health Solution	Outcomes
2016 [78]	n = 228 Intervention aged 55.5 ± 12.3 years and BMI 29.3 ± 5.8 kg/m2; Control aged 51.2 ± 11.9 years and BMI 29.6 ± 6.3 kg/m2 67% female	Intervention—Get Healthy, Stay Healthy (GHSH; via individually tailored text messages, with data collected during two telephone calls with goal setting and targets consistent with national guidelines) Control—brief written feedback of results following each assessment, no other contact	Significant intervention effects on weight loss at 6-months (p = 0.003), moderate PA sessions/week (p = 0.008), and accelerometer-assessed MVPA (p = 0.007) No difference in waist circumference, dietary outcomes, and other PA outcomes between groups
2015 [79]	n = 196 males Intervention aged 41.02 ± 6.82 years and BMI 28.0 ± 2.15 kg/m2; Control aged 41.55 ± 6.98 years and BMI 27.6 ± 2.5 kg/m2 0% female	Intervention—6-month programme including tailored text message reminders every other day, plus four offline education sessions and brief counselling with monthly weight checks by nurses for weight control Control—four offline education sessions and brief counselling with monthly weight checks by nurses about weight control	Both groups significantly reduced their body weight compared with baseline (1.71 kg intervention vs. 1.56 kg control). At 1 month, weight loss was significant between groups (p = 0.01) but at 6 months, weight loss between groups was not significant (p = 0.78) There was no significant difference between groups for % body fat (p = 0.60) and PA min/wk (p = 0.14) at 6 months
2021 [80]	n = 459 aged 23.3 ± 4.4 years; BMI 31.2 ± 4.4 kg/m2 79% female	Targeted—Facebook content and generic daily text messages to reinforce self-monitoring and provide tips. The intervention was weight loss focussed including content adapted from the Diabetes Prevention Programme with calorie, weight loss, and PA goals Tailored—Facebook content and 6 tailored text messages/wk—specific prompts for self-monitoring weight, PA, with additional personal and generic messages for feedback, tips and reminders. Intervention was weight loss focussed including content adapted from the Diabetes Prevention Programme with calorie, weight loss, and PA goals Control—Facebook delivery component. Wellness content related to healthy body weight (e.g., sleep, stress, body image). The content was educational rather than focussing on specific behaviour change	No overall effect of the treatment group on 6, 12, and 18-month weight loss Subset engagement analysis: engagement in ≥66% of the personalised intervention (Tailored) lost more weight vs. the control group at 6 months (p = 0.004), with the trend continuing at 12 months (p = 0.05), but disappearing by 18 months Participants in the lowest BMI category (25–27.5 kg/m2) in the Tailored group lost 2.27 kg more than the control (p = 0.006) and those in the Targeted group lost 1.72 kg more than the control (p = 0.02) after adjusting for covariates at 6 months
2014 [81]	n = 185 aged 35.4 ± 5.5 years; BMI 30.2 ± 2.5 kg/m2 100% female	Shape programme (12 months)—behaviour change goals to promote weight loss, self-monitoring via weekly interactive voice response (IVR) calls, tailored skills training materials, monthly dietitian calls, 12-month YMCA membership Control—usual care (routine standard of care from providers)	IVR completion rate at 12 months was 71.6 ± 28.1% (weekly range from 52–96%) and 52% had an IVR completion rate of ≥80% with two-thirds completing at least 60% of IVR calls At 12 months, IVR call completion was significantly correlated with weight loss (p = 0.04) and those with ≥80% IVR completion rate had greater weight loss vs. those who had <80% IVR completion rate (p = 0.01), with similar outcomes for BMI (mean difference −0.94 kg m2; p = 0.009) (−0.70 ± 0.25 kg/m2 ≥80% IVR completion rate vs. 0.25 ± 0.25 kg/m2 <80% IVR completion rate)
2015 [82]	n = 67 aged 48.2 ± 11.7 years; BMI 31.0 ± 3.7 kg/m2 91% female	Intervention—self-monitoring with Fitbit One tracker + SMS-based PA prompts Control—self-monitoring with Fitbit One only	Significant between-group differences in PA change from baseline to week 1 for steps (p = 0.01), fairly/very active minutes (p < 0.01), and total active minutes (p = 0.02), but these changes in PA were the short-term and not maintained through weeks 2–6 Significant within-group increase of +4.3 ±2.0 min/week of MVPA from baseline to 6 weeks follow up in the control group (p = 0.04), but no group differences across PA levels
2018 [83]	n = 191 aged 49 ± 10.5 years; BMI 36.7 ± 4.3 kg/m2 92% female	Participants had lost at least 5 kg during the first 4–6 months in the WW programme and then recruited to one of three arms for 6 months, followed by passive monitoring for months 7–12; Direct—WW + direct monetary incentive + daily self-weighing and text messaging feedback Lottery—WW + additional lottery-based monetary incentive + daily self-weighing and text messaging feedback Control—daily self-weighing and text messaging feedback	Weight loss pre-trial before randomisation was 11.4 ± 4.7 kg Maintenance of weight loss occurred across all arms (direct −2.8 ± 5.8 kg, lottery −3.0 ± 5.8 kg, control −1.4 ± 5.8 kg), significant in the two intervention arms (p < 0.001) but not control. There was no significant difference between arms for weight loss at 12 months (p > 0.1) and changes in self-reported PA and eating behaviours did not differ across arms Participants who maintained their weight loss (defined as gaining ≤1.36 kg) at 6 months—lottery 79%, direct 76%, control 67% (p > 0.1); 12 months p > 0.1