D22-02 Predictors of Hypercapnia-Related Readmission in Obesity Hypoventilation Syndrome: A Multi-Center Real-World Analysis Using the Trinetx Network

Background Obesity hypoventilation syndrome (OHS) is a growing cause of morbidity in the era of the obesity epidemic and is frequently complicated by episodes of acute hypercapnic respiratory failure. These patients often require recurrent hospitalizations due to ventilatory decompensation, yet limited data exist on real-world predictors of early readmission. Understanding which factors predispose to recurrent hypercapnia is essential for developing targeted discharge strategies and improving care coordination across inpatient and outpatient settings. Methods We conducted a multicenter retrospective cohort study using the TriNetX Research Network (2015-2024. Adults aged ≥18 years with a body mass index (BMI) ≥30 kg/m², a diagnosis of OHS (ICD-10 G47.34), and an index hospitalization for acute hypercapnic respiratory failure (PaCO2 > 45 mmHg) were included. The primary outcome was 30-day all-cause hospital readmission associated with hypercapnia. Secondary outcomes included 90-day mortality and emergency department revisits. Predictors of readmission evaluated included use of home noninvasive ventilation (NIV) on discharge, home oxygen, comorbid heart failure, chronic kidney disease (CKD), obstructive sleep apnea (OSA), and outpatient sleep-clinic follow-up within 14 days. Multivariable logistic regression was performed to identify independent predictors after adjusting for age, sex, BMI, and Charlson comorbidity index. Results A total of 3,120 patients met inclusion criteria (mean age 57 ± 11 years; 61% female; mean BMI 43 kg/m²). The 30-day readmission rate for hypercapnic respiratory failure was 22%. On multivariable analysis, significant predictors of readmission included absence of outpatient sleep-clinic follow-up within 14 days (OR 2.1, 95% CI 1.6-2.8), chronic heart failure (OR 1.7, 95% CI 1.3-2.2), CKD stage ≥3 (OR 1.5, 95% CI 1.1-2.0), and discharge without home NIV (OR 1.8, 95% CI 1.4-2.3). Patients discharged with both home NIV and timely sleep-clinic follow-up had substantially lower 30-day readmission (12% vs 28%, p < 0.001) and 90-day mortality (3.5% vs 7.8%, p = 0.02). Conclusion In this large, real-world cohort of OHS patients, early outpatient engagement and access to home ventilatory support emerged as key determinants of readmission risk. Lack of early sleep-clinic follow-up and failure to prescribe home NIV were strongly associated with recurrent hypercapnia. These findings underscore the need for standardized post-discharge pathways that ensure prompt sleep medicine evaluation, optimization of home ventilatory therapy, and proactive management of comorbid heart and renal disease. Implementation of such strategies could meaningfully reduce readmissions and improve outcomes for patients with obesity hypoventilation syndrome. This abstract is funded by: None