Association of Changing Hospital Readmission Rates With Mortality Rates After Hospital Discharge

Key Points

Question

Have hospital readmission reductions associated with the Affordable Care Act had the unintended consequence of increasing mortality after hospitalization?

Findings

In this cohort study of more than 5 million Medicare fee-for-service hospitalizations for heart failure, acute myocardial infarction, and pneumonia from 2008 to 2014, reductions in hospital 30-day readmission rates were weakly but significantly correlated with reductions in 30-day mortality rates after hospital discharge (correlation coefficients, 0.066, 0.067, and 0.108, respectively).

Meaning

These findings do not support increasing postdischarge mortality related to reducing hospital readmissions.

Abstract

This cohort study examines whether reductions in hospital readmission rates following hospitalizations for heart failure, acute myocardial infarction, and pneumonia are associated with mortality rates after hospital discharge among Medicare fee-for-service beneficiaries.

Abstract

Importance

The Affordable Care Act has led to US national reductions in hospital 30-day readmission rates for heart failure (HF), acute myocardial infarction (AMI), and pneumonia. Whether readmission reductions have had the unintended consequence of increasing mortality after hospitalization is unknown.

Objective

To examine the correlation of paired trends in hospital 30-day readmission rates and hospital 30-day mortality rates after discharge.

Design, Setting, and Participants

Retrospective study of Medicare fee-for-service beneficiaries aged 65 years or older hospitalized with HF, AMI, or pneumonia from January 1, 2008, through December 31, 2014.

Exposure

Thirty-day risk-adjusted readmission rate (RARR).

Main Outcomes and Measures

Thirty-day RARRs and 30-day risk-adjusted mortality rates (RAMRs) after discharge were calculated for each condition in each month at each hospital in 2008 through 2014. Monthly trends in each hospital’s 30-day RARRs and 30-day RAMRs after discharge were examined for each condition. The weighted Pearson correlation coefficient was calculated for hospitals’ paired monthly trends in 30-day RARRs and 30-day RAMRs after discharge for each condition.

Results

In 2008 through 2014, 2 962 554 hospitalizations for HF, 1 229 939 for AMI, and 2 544 530 for pneumonia were identified at 5016, 4772, and 5057 hospitals, respectively. In January 2008, mean hospital 30-day RARRs and 30-day RAMRs after discharge were 24.6% and 8.4% for HF, 19.3% and 7.6% for AMI, and 18.3% and 8.5% for pneumonia. Hospital 30-day RARRs declined in the aggregate across hospitals from 2008 through 2014; monthly changes in RARRs were −0.053% (95% CI, −0.055% to −0.051%) for HF, −0.044% (95% CI, −0.047% to −0.041%) for AMI, and −0.033% (95% CI, −0.035% to −0.031%) for pneumonia. In contrast, monthly aggregate changes across hospitals in hospital 30-day RAMRs after discharge varied by condition: HF, 0.008% (95% CI, 0.007% to 0.010%); AMI, −0.003% (95% CI, −0.005% to −0.001%); and pneumonia, 0.001% (95% CI, −0.001% to 0.003%). However, correlation coefficients in hospitals’ paired monthly changes in 30-day RARRs and 30-day RAMRs after discharge were weakly positive: HF, 0.066 (95% CI, 0.036 to 0.096); AMI, 0.067 (95% CI, 0.027 to 0.106); and pneumonia, 0.108 (95% CI, 0.079 to 0.137). Findings were similar in secondary analyses, including with alternate definitions of hospital mortality.

Conclusions and Relevance

Among Medicare fee-for-service beneficiaries hospitalized for heart failure, acute myocardial infarction, or pneumonia, reductions in hospital 30-day readmission rates were weakly but significantly correlated with reductions in hospital 30-day mortality rates after discharge. These findings do not support increasing postdischarge mortality related to reducing hospital readmissions.