A comparison of rates and predictors of hospital readmission: Outpatient versus inpatient mastectomy for breast cancer.

Abstract

116 Background: The odds of readmission have been reported to be slightly higher with outpatient (OP) compared to inpatient (IP) mastectomy, although overall rates are low. While OP mastectomy procedures have become more common, predictors of readmission and current rates are unknown. Methods: Observational study of women 18+ years who underwent mastectomy in California from 2005-2009 from the Healthcare Cost and Utilization Project (HCUP) linked state database. Associations of readmission and post-mastectomy complications with length of stay (LOS) were assessed using Jonkheere – Terpstra test for trend. Multivariate logistic regression was used to test the association of LOS with readmission to hospital within 30 days, adjusting for patient, clinical, and hospital factors. Results: Readmission rates for OP compared to IP mastectomy was 3.3 % vs. 5.6% (p<0.0001). OP mastectomy had the highest hematoma/seroma and chemotherapy related anemia/ neutropenia readmissions (19% p=0.0112; 2.9% p=0.0009). Readmits for cardiopulmonary events were higher for the longest LOS. Multivariate analysis showed increased readmission rates by LOS, race, payer, comorbidities (all p-values <0.0001). Odds of readmission were higher with increasing LOS vs. OP (1d OR 1.13 95% CI 0.99-1.3; 2d OR 1.6 95%CI 1.4-1.8; ≥3d OR 3.0 95%CI 2.6-3.4). Increased odds of readmission was associated with African-Americans (OR 1.5 95%CI 1.2-1.9) and Whites (OR 1.4 95%CI 1.2-1.7) vs. Asians. Revisit rates were higher with Medicare (OR 1.7 95%CI 1.4-1.9) and Medicaid (OR 1.6 95%CI 1.3-1.8) compared to private insurance. The highest readmission rates were ≥ 3 comorbidities (OR 2.7 95%CI 2.2-3.2). Conclusions: In California, readmission rates increase with increasing LOS. Risks of readmission following IP mastectomy are higher compared to OP. Low readmission rates suggest appropriate selection of patients for OP mastectomy. However, subsets of patients are at higher risk of readmission. Additional studies of patients with extended LOS; racial disparities in access to services; and evaluation of payer policies are needed to improve care and decrease hospital readmissions.