Care fragmentation and readmission mortality and length of stay before and during the COVID-19 pandemic: data from the National Readmissions Database, 2018–2020

Abstract Importance A quarter of all 30-day readmissions involve fragmented care, where patients return to a different hospital than their original admission; these readmissions are associated with increased in-hospital mortality and longer lengths-of-stay (LOS). The stress on healthcare systems at the beginning of the COVID-19 pandemic could worsen care fragmentation and related outcomes. Objective To compare fragmented readmissions in 2020 versus 2018–2019 and assess whether mortality and LOS in fragmented readmissions differed in the two time periods. Design Observational study Setting National Readmissions Database (NRD), 2018–2020 Participants All adults (> 18 y/o) with 30-day readmissions Main outcomes and measures We examined the percentage of fragmented readmissions over 2018–2020. Using unadjusted and adjusted logistic and linear regressions, we estimated the associations between fragmented readmissions and in-hospital mortality and LOS. Results 24.0–25.7% of readmissions in 2018–2020 and 27.3%-31.0% of readmissions for COVID-19 were fragmented. 2018–2019 fragmented readmissions were associated with 18–20% higher odds of in-hospital mortality compared to nonfragmented readmissions. Fragmented readmissions for COVID-19 were associated with an 18% increase in in-hospital mortality (AOR 1.18, 95% CI 1.12, 1.24). The LOS of fragmented readmissions in March-November 2018–2019 were on average 0.81 days longer, while fragmented readmissions between March-November of 2020 were associated with a 0.88–1.03 day longer LOS. Conclusions and relevance A key limitation is that the NRD does not contain information on several patient/hospital-level factors that may be associated with the outcomes of interest. We observed increased fragmentation during COVID-19, but its impact on in-hospital mortality and LOS remained consistent with previous years.