JMIR Publications

ABSTRACT

Background:

Obesity affects over 890 million adults worldwide and traditional lifestyle interventions often lack long-term success. While GLP-1 receptor agonists have shown strong weight loss outcomes, access to specialist care is limited by cost and capacity.

Objective:

This study evaluated the effectiveness, feasibility, acceptability, and potential cost-effectiveness of a 12-month remote GLP-1RA-supported weight management program, comparing outcomes between tirzepatide and semaglutide.

Methods:

This retrospective analysis included 339 participants (82% women) who completed a 12-month remote weight management program with either tirzepatide (n=209) or semaglutide (n=130) between February and June 2024. The program combined medication, app-based behavioral support, coaching from registered dietitians/nutritionists, and clinical oversight. It featured five phases with evidence-based behavior change techniques, monthly monitoring, and safety protocols. Primary outcomes were mean weight change and proportions achieving ≥10% and ≥15% weight loss. Secondary outcomes included behavioral changes, side effects, acceptability, feasibility, and estimated cost-effectiveness compared to NHS care.

Results:

Mean weight change at 12 months was -22.9 kg (-22.1% of baseline weight, SD=8.0, P<0.05) in the tirzepatide cohort and -18.1 kg (-17.1% of baseline weight, SD=8.1, P<0.05) in the semaglutide cohort. Achievement of ≥10% weight loss occurred in 95.2% of tirzepatide participants and 83.1% of semaglutide participants, while ≥15% weight loss was achieved by 83.7% and 56.2%, respectively. The proportion of inactive participants (no weekly exercise) decreased substantially in both cohorts (tirzepatide: 14.8% to 6.7%; semaglutide: 22.3% to 5.4%, P<0.05). Side effects decreased significantly over the 12-month period, with participants reporting no side effects increasing from 41.6% to 60.3% (tirzepatide) and from 53.8% to 67.7% (semaglutide), while common initial side effects including constipation, nausea, and fatigue showed significant reductions (p < 0.05). Economic modelling suggested a 60-70% cost saving compared to specialist weight management services and a 10-60% cost saving compared to primary care services in the NHS.

Conclusions:

This real-world evaluation demonstrates that remotely delivered, GLP-1RA-supported weight management programs can achieve weight loss outcomes that align closely with clinical trial results while potentially reducing healthcare costs by 10-70% compared to traditional UK services. Both tirzepatide and semaglutide cohorts exceeded clinically significant weight loss thresholds with acceptable safety profiles and positive behavioural changes. These findings support the feasibility and effectiveness of digital delivery models for expanding access to specialist obesity treatment within resource-constrained healthcare systems, with outcomes that compare favourably to pharmacological intervention alone.