Understanding Hospital Complexity in Public Bariatric Surgery: A 6-Year Population-Based Study in Chile

Background: Obesity represents a growing public health challenge in Latin America, with Chile reporting among the highest regional prevalence rates. Bariatric surgery is a cost-effective intervention for obesity; however, its implementation within public healthcare systems remains underexplored. Objective: To characterize the clinical and demographic profile of bariatric surgery patients in the Chilean public system and to assess the impact of obesity-related comorbidities on hospital complexity using Diagnosis-Related Group (DRG). Methods: A retrospective cross-sectional study analyzed 4,541 bariatric procedures performed between 2019 and 2024 in 72 public hospitals. Cases were identified using ICD-9-CM and ICD-10 codes and stratified by DRG complexity (≤ 1.25 vs. >1.25). Bivariate and multivariate logistic regression models examined associations between patient characteristics and higher DRG complexity. Results: Patients were predominantly female (86.5%) and aged 35–55 years (60.5%). The most frequent comorbidities were hypertension (33.2%) and hepatic steatosis (29.1%). DRG complexity exceeded 1.25 in 26.3% of cases. Independent predictors of higher complexity included age ≥ 35, female sex, hypertension (OR: 1.25), and prolonged medication use (OR: 5.05). In contrast, type 2 diabetes and impaired glucose tolerance were associated with lower complexity. Residence outside the Metropolitan Region also significantly increased complexity (OR: 1.78). Conclusions: Sociodemographic and clinical variables are significantly associated with hospital complexity in bariatric surgery. Incorporating DRG data into policy and planning can improve equity, optimize care pathways, and strengthen resource distribution in public health systems.