Coronary artery bypass grafting at safety-net versus non–safety-net hospitals

Open AccessPublished:January 23, 2023DOI:
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      Safety-net hospitals (SNHs) provide essential services to predominantly underserved patients regardless of their ability to pay. We hypothesized that patients who underwent coronary artery bypass grafting (CABG) would have inferior observed outcomes at SNHs compared with non-SNHs but that matched cohorts would have comparable outcomes.


      We queried the Nationwide Readmissions Database for patients who underwent isolated CABG from 2016–2018. We ranked hospitals by the percentage of all admissions in which the patient was uninsured or insured with Medicaid; hospitals in the top quartile were designated as SNHs. We used propensity-score matching to mitigate the effect of confounding factors and compare outcomes between SNHs and non-SNHs.


      A total of 525,179 patients underwent CABG, including 96,133 (18.3%) at SNHs, who had a greater burden of baseline comorbidities (median Elixhauser score 8 vs 7; P =.04) and more frequently required urgent surgery (57.1% vs 52.8%; P <.001). Observed in-hospital mortality (2.1% vs 1.8%; P =.004) and major morbidity, length of stay (9 vs 8 days; P <.001), cost ($46,999 vs $38,417; P <.001), and readmission rate at 30 (12.4% vs 11.3%) and 90 days (19.0% vs 17.7%) were greater at SNHs (both P <.001). After matching, none of these differences persisted except length of stay (9 vs 8 days) and cost ($46,977 vs $39,343) (both P <.001).


      After matching, early outcomes after CABG were comparable at SNHs and non-SNHs. Improved discharge resources could reduce length of stay and curtail cost, improving the value of CABG at SNHs.

      Graphical abstract


      Abbreviations and Acronyms:

      AHRQ (Agency for Healthcare Research and Quality), CABG (Coronary artery bypass grafting), CI (Confidence interval), HCUP (Healthcare Cost and Utilization Project), LOS (Length of stay), NRD (Nationwide Readmissions Database), OR (Odds ratio), SNH (Safety-net hospital)