Back to 2019 Posters

---

30-DAY READMISSION AFTER REVISIONAL BARIATRIC SURGERY: INCIDENCE, MORTALITY AND INPATIENT COSTS
Violeta Popov^*1, Christopher C. Thompson^2
1NYU School of Medicine, New York, NY; ²Brighma and Women's Hospital, Boston, MA, MA

Bariatric surgery has been shown to improve obesity-related comorbidities. However, it is associated with weight regain and adverse events that may lead to reoperation. Revisional bariatric procedures have increased from 6% of all bariatric operations in 2011 to 14% in 2017. This may underestimate operations to treat bariatric complications. A review of the bariatric surgery registry suggests a 30-day mortality of approximately 0.12-0.21%.

Aims: To determine the 30-day mortality, causes, and costs of readmission following inpatient revisional bariatric procedures using the largest national readmission database. Secondary aims included evaluating independent risk factors for readmissions.

Methods: This is a retrospective cohort analysis of the 2014 Nationwide Inpatient Readmission (NRD) database. Cases were included if they had an ICD 9 procedure codes during their index admission indicating revisional bariatric surgery. A readmission was defined as the first admission to any hospital for any non-trauma diagnosis within 30 days of the index admission. Same day admissions and discharges were excluded. Any subject that had a diagnosis code of gastrointestinal and hepatobiliary malignancy was excluded, as well as subjects with inflammatory bowel disease. The primary outcomes were 30-day readmission and mortality rates. Secondary outcomes were the most common readmission diagnosis and resource utilization (length of stay and hospitalization total costs). Independent risk factors for readmission were identified using multivariate regression analysis.

Results: A total of 69, 292 patients who underwent bariatric revisional procedures in 2014 were captured in NRD. 4.8% (3295 patients) were readmitted within 30 days. Post-operative inpatient mortality was 0.6% for the index admission, and 1.6 % for the readmission, with a total 30-day mortality of 0.73%. Mean age was 47.4, 77.7 % were female, 4.8 % had an ICU stay, mean LOS was 3.69 days, and with a mean charge per patient of 63,774 USD. The cumulative length of stay of all readmitted patients was 14,328 days, with a total cost of 33 million dollars, and total charges of 123 million dollars. The most common 30-day readmissions were related to dehydration and vomiting, and bariatric complications (Figure 1). Older age, lower income by ZIP code and ICU stay during the index admission were significant predictors of readmission (Table 1).

Conclusion: The 30-day post-operative inpatient mortality rate for revisional bariatric procedures is 0.73%, which is significantly higher than previously thought. The discrepancy between reported surgical registry data mortality (0.12-0.21%) and data recorded in the NRD is worrisome and warrants additional investigations. 30-day readmissions may be preventable such as later discharge for patients after ICU stay and further studies to assess modifiable risk factors are needed.

Table 1. Univariate and multivariate risk factors for 30-day readmission. OR, odds ratio; 95%CI, 95% confidence interval

Factor	Univariate Odds Ratio Mortality			Multivariate Odds Ratio
	OR	95%CI	P	OR	95%CI	P
Age	1.01	1.005,1.02	<0.001	1.01	1.004,1.02	<0.001
Female	0.87	0.7, 1.01	0.06
Income by ZIP code (highest quartile vs. lowest quartile)	0.7	0.6, 0.8	0.001	0.8	0.6, 0.9	0.003
ICU stay on index admission	3.2	2.3, 4.4	<0.001	2.6	1.7, 3.8	<0.001
Shock on index admission	2.8	1.7, 4.8	<0.001	1.5	0.8, 2.7	0.2
Hospital bedsize (largest vs others)	0.99	0.9, 1.5	0.7
Teaching vs nonteaching hospital	1.04	0.9,1.2	0.6

Significant univariate predictors were used in the multivariate model


Figure 1. Most common 30-day readmission diagnoses after revisional bariatric procedures

---

Back to 2019 Posters