Understanding the clinical characteristics associated with health care costs and cost savings upon weight reduction in individuals with obesity or overweight

Abstract Aims This study aimed to (1) identify characteristics of people with obesity or overweight that are predictive of health care costs; and (2) identify potential subgroups associated with weight reduction and cost savings following weight reduction interventions. Materials and Methods This retrospective cohort study used the Optum MarketClarity database from 2014 to 2022. The primary objective was assessed among individuals ≥19 years old with obesity/overweight with ≥12 months of continuous medical/pharmacy enrolment (primary cohort; index date: date of body mass index BMI measure ≥27 kg/m 2 closest to December 31, 2022). The secondary objective was assessed among individuals using obesity management medication (OMM cohort)/bariatric surgery (surgery cohort). Generalised linear model (GLM) and random forest (RF) models were fitted to identify covariates predictive of total costs. Logistic regression, RF, and Lasso models were used to identify predictors of cost savings and ≥10% weight reduction. Results Outpatient visits, inpatient days, emergency room visits, and Charlson Comorbidity Index were main drivers of health care costs in GLM and RF models. Obesity‐related complications (ORCs) including gastroesophageal reflux disease, osteoarthritis‐knee and hip, coronary heart disease, hypertension, and heart failure were also influential predictors of cost, associated with approximately 2–4‐fold higher median costs. The strongest predictors of cost savings and ≥10% weight reduction were baseline costs, outpatient visits (OMM cohort) and metabolic syndrome (surgery cohort). Conclusions Findings underscore ORCs as key drivers of health care costs and highlight the need for targeted treatment strategies to effectively manage obesity, reduce the risk and severity of ORCs, and control health care costs. Furthermore, understanding baseline costs and treatment‐related cost trajectories across patient subgroups offers critical insights to inform both clinical decision‐making and health policy design.