S. Hinks1, S. Sakowitz1, E. Aguayo1, T. Coaston1, S. Mallick1, S.S. Ali1, P. Benharash1,2 2David Geffen School Of Medicine, University Of California At Los Angeles, Center For Advanced Surgical & Interventional Technology, Los Angeles, CA, USA 1David Geffen School Of Medicine, University Of California At Los Angeles, Cardiovascular Outcomes Research Laboratories (CORELAB), Los Angeles, CA, USA
Introduction:
Prior work has considered the impact of patient and hospital factors on unplanned readmission following cardiac surgery. Yet the impact of neighborhood-level socioeconomic vulnerability remains to be elucidated. Using a multi-institutional database from a state-wide collaborative, we analyzed the association of greater social vulnerability with 30-day readmission.
Methods:
The 2018-2023 University of California Consortium Society of Thoracic Surgeons Adult Cardiac Database was queried to identify all adult patients (≥18 years) undergoing elective or emergent coronary artery bypass grafting and/or valve procedures. The Haversine formula was applied to compute the distance between patient residence and operating hospital. Structural vulnerability was assessed using the well-validated social vulnerability index (SVI). Briefly, this index evaluates neighborhood-level vulnerability across four domains (socioeconomic status, housing and transportation, race and ethnicity, and household composition), and ranks communities from 0 (least vulnerable) to 1 (most vulnerable). Following prior methodology, SVI was stratified into quartiles, with those of Least Vulnerable (LV) and Most Vulnerable (MV) compared in a pairwise approach. Kaplan Meier time-to-event analyses and Cox proportional hazard models were utilized to assess non-elective readmission within 30-days.
Results:
Among 1,731 patients, 629 (36%) were Most Vulnerable and 1,102 (64%) Least Vulnerable. On average when compared to LV, the MV cohort was similar in age (63 [53-70] vs. 63 [53-70] years, P=0.66), more often of female sex (32.7 vs 27.4%, P=0.02), and less commonly of white race (56.9 vs. 62.0%, P<0.001). In addition, such patients had a higher direct cost (111,475 vs. $91,685, P=0.03), preprocedural length of stay (LOS) (4.9 vs. 4.2 days, P=0.01), and lower mean distance to the index hospital (179.0 vs. 268.9 kilometers, P<0.001). After multivariable adjustment, MV was significantly associated with an increment in index hospitalization costs (β= + $9,643, 95% CI [$866 – $18,421]) and increased odds of 30-day readmission (adjusted odds ratio 1.70, 95% CI [1.03-2.81]) (Figure).
Conclusion:
Compared to patients with a low social vulnerability index, patients in the highest SVI quartile experienced a higher rate of index hospitalization costs and 30-day readmissions. The incorporation of SVI into risk stratification may improve perioperative outcomes.