From measured BMI to documented obesity in hospitalized adults: a decade-long analysis and implications for cardiometabolic care

Obesity contributes substantially to cardiometabolic and overall morbidity and mortality, yet remains underdiagnosed in clinical practice. We aimed to assess discharge documentation rates of obesity among hospitalized patients with elevated body mass index (BMI) and compare these with coding rates of other cardiometabolic risk factors. We conducted a cross-sectional analysis of adults hospitalized between 2013 and 2023 with BMI ≥ 30 kg/m² and no prior coded obesity or bariatric surgery. Obesity and metabolic comorbidities were identified via ICD-9 codes. Among 42,243 eligible adults (mean age 60.9 ± 16.9 years; 49.7% women; mean BMI 33.9 ± 3.9 kg/m²), only 10.6% had obesity documented at discharge. The likelihood of coding increased by 17% for each additional BMI unit (OR 1.17, 95% CI 1.16–1.18). Documentation was associated with higher utilization of obesity-related care, including metabolic clinic attendance (OR 2.26, 95% CI 2.05–2.49), bariatric surgery (OR 3.51, 95% CI 2.74–4.51), and GLP-1 receptor agonist prescriptions (OR 3.44, 95% CI 2.76–4.28). In comparison, diabetes was documented in 59.7% of patients with HbA1c ≥ 6.5%, and severe dyslipidemia in 39.0% of those with LDL-C ≥ 190 mg/dL. Despite being objectively measurable, obesity remains substantially underdocumented compared with other cardiometabolic risk factors. Documentation was associated with greater uptake of metabolic clinic visits, bariatric surgery, and GLP-1 receptor agonist therapy. As effective obesity treatments become routine practice, closing this documentation gap is a prerequisite for translating measured BMI into actionable care.