Thirty-Day Readmission After Bariatric Surgery: Causes, Effects on Outcomes, and Predictors.

BACKGROUND: Bariatric surgery (BSx) is one of the most common surgical procedures in North America. Readmissions may be associated with a high burden to the healthcare system. METHODS: Retrospective study of the 2016 National Readmission Database of adult patients readmitted within 30 days after an index admission for BSx. Outcomes were: 30-day readmission rate, mortality, healthcare-related utilization resources, and independent predictors of readmission. Comparison groups were index admission, readmitted, and non-readmitted patients. RESULTS: A total of 161,141 patients underwent BSx. The 30-day readmission rate was 3.3%. Main causes for readmission were dehydration, acute kidney injury, venous thromboembolism events, and sepsis. Readmitted patients were more likely to develop shock (0.5% vs. 0.1%; P < 0.01) with no differences in mechanical ventilation (1.9% vs. 2.0%; P = 0.83) during index admission compared to non-readmitted patients. Readmission was associated with higher in-hospital mortality rate (1.5% vs. 0.1%; P < 0.01) and prolonged length of stay (4.6 vs. 2.4 days; P < 0.01). The total in-hospital economic burden of readmission was $234 million in total charges and $58.7 million in total costs. Independent predictors of readmission were: Charlson comorbidity index of ≥ 3, longer length of stay, admission to larger bed size hospitals, discharge to nursing home, and acute kidney injury. Medicaid, private insurance, BMI of 30-39 kg/m2, and 40-44 kg/m2 were associated with lower odds for readmission. CONCLUSION: Readmissions after BSx are associated with higher in-hospital mortality rate and pose a high healthcare burden. We identified risk factors that can be targeted to decrease readmissions after BSx, healthcare burden, and patient morbidity and mortality.