Assessment of Hospital Readmissions From the Emergency Department After Implementation of Medicare's Hospital Readmissions Reduction Program.

Importance: The Medicare Hospital Readmissions Reduction Program (HRRP) is associated with reduced readmission rates, but it is unknown how this decrease occurred. Objective: To examine whether the HRRP was associated with changes in the probability of readmission at emergency department (ED) visits after hospital discharge (ED revisits) overall and depending on whether admission is typically indicated for the patient's condition at the ED revisit. Design, Setting, and Participants: This retrospective cohort study used hospital and ED discharge data from California, Florida, and New York from January 1, 2010, to December 31, 2014. A difference-in-differences analysis examined change in readmission probability at ED revisits for recently discharged patients; ED revisits with clinical presentations for which admission is typically indicated vs those for which admission is more variable (ie, discretionary) were examined separately. Inclusion criteria were Medicare patients 65 years and older who revisited an ED within 30 days of inpatient discharge. Data were analyzed from December 18, 2018, to September 11, 2019. Exposures: Before and after HRRP implementation among patients initially hospitalized for targeted vs nontargeted conditions. Main Outcomes and Measures: Thirty-day unplanned hospital readmissions at the ED revisit. Results: A total of 9 914 068 index hospitalizations were identified in California, Florida, and New York from 2010 to 2014. Of 2 052 096 discharges in 2010, 1 168 126 (56.9%) discharges were women and 566 957 discharges (27.6%) were among patients older than 85 years. Among 1 421 407 patients with an unplanned readmission within 30 days of discharge, 1 266 107 patients (89.1%) were admitted through the ED. A total of 1 906 498 ED revisits were identified. After adjusting for patient demographic and clinical characteristics from the index hospitalization, HRRP implementation was associated with fewer readmissions from the ED, with a difference-in-difference estimate of -0.9 (95% CI, -1.4 to -0.4) percentage points (P < .001), or a 1.4% relative decrease from the 65.8% pre-HRRP readmission rates. Implementation of the HRRP was associated with fewer readmissions at the ED revisit involving clinical presentations for which admission is typically indicated (difference-in-differences estimate, -1.1 [95% CI, -1.6 to -0.6] percentage points; P < .001), or a 1.2% relative decrease from the 93.6% pre-HRRP rate. These results appear to be associated with patients presenting at the ED revisit with congestive heart failure (difference-in-difference estimate, -1.2 [95% CI, -2.0 to -0.4] percentage points; P = .003). Conclusions and Relevance: These findings suggest that implementation of the HRRP was associated with a lower likelihood of readmission for recently discharged patients presenting to the ED, specifically for congestive heart failure. This highlights the critical role of the ED in readmission reduction under the HRRP and suggests that patient outcomes after HRRP implementation should be further studied.