Prior Hospitalization Burden and the Relatedness of 30-Day Readmissions in Patients Receiving Hemodialysis

Significance Statement Patients receiving hemodialysis have a high 30-day readmission rate after hospitalization, and Medicare financially penalizes providers with rates that are higher than expected. However, quality measures currently do not account for whether 30-day readmissions are indeed related to the cause for the index hospitalization. This study demonstrates that Medicare patients receiving hemodialysis are significantly more likely to experience an unrelated 30-day readmission if they have a high baseline hospitalization rate, which itself is associated with having more comorbidities and Medicaid status. A related 30-day readmission is most likely to follow cardiac index hospitalizations and least likely to follow renal index hospitalizations. The authors suggest that Medicare consider incorporating prior hospitalization burden and clinical relatedness to improve the clinical meaningfulness of its 30-day readmission quality metrics. Background Thirty-day readmissions are common in patients receiving hemodialysis and costly to Medicare. Because patients on hemodialysis have a high background hospitalization rate, 30-day readmissions might be less likely related to the index hospitalization than in patients with other conditions. Methods In adults with Medicare receiving hemodialysis in the United States, we used multinomial logistic regression to evaluate whether prior hospitalization burden was associated with increased 30-day readmissions unrelated to index hospitalizations with a discharge date from January 1, 2013 to December 31, 2014. We categorized a hospitalization, 30-day readmission pair as “related” if the principal diagnoses came from the same organ system. Results The adjusted probability of unrelated 30-day readmission after any index hospitalization was 19.1% (95% confidence interval [95% CI] 18.9% to 19.3%), 22.6% (95% CI, 22.4% to 22.8%), and 31.2% (95% CI, 30.8% to 31.5%) in patients with 0–1, 2–4, and ≥5 hospitalizations, respectively. Cardiovascular index hospitalizations had the highest adjusted probability of related 30-day readmission: 10.4% (95% CI, 10.2% to 10.7%), 13.6% (95% CI, 13.4% to 13.9%), and 20.8% (95% CI, 20.2% to 21.4%), respectively. Renal index hospitalizations had the lowest adjusted probability of related 30-day readmission: 2.0% (95% CI, 1.8% to 2.3%), 3.9% (95% CI, 3.4% to 4.4%), and 5.1% (95% CI, 4.3% to 5.9%), respectively. Conclusions High prior hospitalization burden increases the likelihood that patients receiving hemodialysis experience a 30-day readmission unrelated to the index hospitalization. Health care payers such as Medicare should consider incorporating clinical relatedness into 30-day readmission quality measures.