Importance: Maintaining competition among hospitals is increasingly seen as important to achieving high-quality outcomes. Whether or not there is an association between hospital market competition and outcomes after high-risk surgery is unknown.
Objective: To evaluate whether there is an association between hospital market competition and outcomes after high-risk surgery.
Design, setting, and participants: We performed a retrospective study of Medicare beneficiaries who received care in US hospitals. Participants were 65 years and older who electively underwent 1 of 10 high-risk surgical procedures from 2015 to 2018: carotid endarterectomy, mitral valve repair, open aortic aneurysm repair, lung resection, esophagectomy, pancreatectomy, rectal resection, hip replacement, knee replacement, and bariatric surgery. Hospitals were categorized into high-competition and low-competition markets based on the hospital market Herfindahl-Hirschman index. Comparisons of 30-day mortality and 30-day readmissions were risk-adjusted using a multivariate logistic regression model adjusting for patient factors (age, sex, comorbidities, and dual eligibility), year of procedure, and hospital characteristics (nurse ratio and teaching status). Data were analyzed from May 2022 to March 2023.
Main outcomes and measures: Thirty-day postoperative mortality and readmissions.
Results: A total of 2 242 438 Medicare beneficiaries were included in the study. The mean (SD) age of the cohort was 74.1 (6.4) years, 1 328 946 were women (59.3%), and 913 492 were men (40.7%). When examined by procedure, compared with low-competition hospitals, high-competition market hospitals demonstrated higher 30-day mortality for 2 of 10 procedures (mitral valve repair: odds ratio [OR], 1.11; 95% CI, 1.07-1.14; and carotid endarterectomy: OR, 1.06; 95% CI, 1.03-1.09) and no difference for 5 of 10 procedures (open aortic aneurysm repair, bariatric surgery, esophagectomy, knee replacement, and hip replacement; ranging from OR, 0.97; 95% CI, 0.94-1.00, for hip replacement to OR, 1.09; 95% CI, 0.94-1.26, for bariatric surgery). High-competition hospitals also demonstrated 30-day readmissions that were higher for 5 of 10 procedures (open aortic aneurysm repair, knee replacement, mitral valve repair, rectal resection, and carotid endarterectomy; ranging from OR, 1.01; 95% CI, 1.00-1.02, for knee replacement to OR, 1.05; 95% CI, 1.02-1.08, for rectal resection) and no difference for 3 procedures (bariatric surgery: OR, 1.03; 95% CI, 0.99-1.07; esophagectomy: OR, 1.02; 95% CI, 0.99-1.06; and pancreatectomy: OR, 1.00; 95% CI, 0.99-1.01). Hospitals in high-competition compared with low-competition markets cared for patients who were older (mean [SD] age of 74.4 [6.6] years vs 74.0 [6.2] years, respectively; P < .001), were more likely to be racial and ethnic minority individuals (77 322/450 404 [17.3%] vs 23 328/444 900 [5.6%], respectively; P < .001), and had more comorbidities (≥2 Elixhauser comorbidities, 302 415/450 404 [67.1%] vs 284 355/444 900 [63.9%], respectively; P < .001).
Conclusions and relevance: This study found that hospital market competition was not consistently associated with improved outcomes after high-risk surgery. Efforts to maintain hospital market competition may not achieve better postoperative outcomes.