GLP-1-Based Therapies for Obesity in Real-World Settings: A Multicountry Cohort Study Using Standardized EHR Data
Author(s)
Milou Brand, PhD1, Atif Adam, MPH, PhD, MD2, Eva Oakkar, PhD3, Mui Van Zandt, BS4.
1Senior Data Scientist, IQVIA, London, United Kingdom, 2IQVIA, Somerville, MA, USA, 3IQVIA, Washington, DC, USA, 4IQVIA, Wayne, PA, USA.
1Senior Data Scientist, IQVIA, London, United Kingdom, 2IQVIA, Somerville, MA, USA, 3IQVIA, Washington, DC, USA, 4IQVIA, Wayne, PA, USA.
OBJECTIVES: GLP-1 receptor agonists have transformed obesity management, with clinical trials reporting 10-15% weight loss. However, it is unclear if these outcomes are replicated in routine clinical practice across diverse healthcare systems. This study utilizes a federated, multi-country network of real-world databases to: (1) evaluate real-world effectiveness of GLP-1 therapies for obesity, (2) assess country-level variability in outcomes, and (3) demonstrate the feasibility of large-scale, privacy-preserving comparative effectiveness research.
METHODS: A retrospective cohort study was conducted using four large-scale EHR databases standardized to the OMOP Common Data Model in UK, France, Germany, and US. Adults with BMI ≥30 kg/m² and baseline and 12-month follow-up BMI measurements after GLP-1 initiation were included. Primary outcome was percentage BMI change at 12 months. Secondary analyses examined treatment persistence and longitudinal BMI trajectories.
RESULTS: Among 7,203 patients (median baseline BMI 35-37.8 kg/m²), change in BMI was substantially lower than clinical trial outcomes. Average BMI reductions ranged from 2.2-3.1% across countries—approximately 3-5 times lower than trial-reported weight loss. The proportion of patients achieving ≥5% BMI reduction ranged from 13.7% in the US to 17.7% in the UK. Significant country-specific heterogeneity emerged: UK showed highest reductions (2.8%, SD=6.3%), US lowest (1.5%, SD=4.8%), with France and Germany intermediate (2.0-2.2%). All reductions were statistically significant (p<.001) but clinically modest compared to expectations based on trial results.
CONCLUSIONS: This federated network analysis reveals a substantial efficacy-effectiveness gap for GLP-1 therapies in real-world obesity management. The marked regional variability highlights how healthcare systems, prescribing practices, adherence patterns, and patient selection critically influence outcomes. Building on the demonstrated feasibility of conducting large-scale, privacy-preserving comparative effectiveness research for obesity management, future research will expand this work to explore additional clinical outcomes and identify key determinants of treatment success across global populations.
METHODS: A retrospective cohort study was conducted using four large-scale EHR databases standardized to the OMOP Common Data Model in UK, France, Germany, and US. Adults with BMI ≥30 kg/m² and baseline and 12-month follow-up BMI measurements after GLP-1 initiation were included. Primary outcome was percentage BMI change at 12 months. Secondary analyses examined treatment persistence and longitudinal BMI trajectories.
RESULTS: Among 7,203 patients (median baseline BMI 35-37.8 kg/m²), change in BMI was substantially lower than clinical trial outcomes. Average BMI reductions ranged from 2.2-3.1% across countries—approximately 3-5 times lower than trial-reported weight loss. The proportion of patients achieving ≥5% BMI reduction ranged from 13.7% in the US to 17.7% in the UK. Significant country-specific heterogeneity emerged: UK showed highest reductions (2.8%, SD=6.3%), US lowest (1.5%, SD=4.8%), with France and Germany intermediate (2.0-2.2%). All reductions were statistically significant (p<.001) but clinically modest compared to expectations based on trial results.
CONCLUSIONS: This federated network analysis reveals a substantial efficacy-effectiveness gap for GLP-1 therapies in real-world obesity management. The marked regional variability highlights how healthcare systems, prescribing practices, adherence patterns, and patient selection critically influence outcomes. Building on the demonstrated feasibility of conducting large-scale, privacy-preserving comparative effectiveness research for obesity management, future research will expand this work to explore additional clinical outcomes and identify key determinants of treatment success across global populations.
Conference/Value in Health Info
2025-11, ISPOR Europe 2025, Glasgow, Scotland
Value in Health, Volume 28, Issue S2
Code
RWD89
Topic
Clinical Outcomes, Epidemiology & Public Health, Real World Data & Information Systems
Topic Subcategory
Distributed Data & Research Networks, Reproducibility & Replicability
Disease
Diabetes/Endocrine/Metabolic Disorders (including obesity)