Evaluation of mortality and readmissions following hospitalization with heart failure

Abstract

Objective: To examine the association of patient/clinical characteristics with mortality and readmission following a heart failure (HF)-related hospitalization.

Research design and methods: Claims data, linked to laboratory, race/ethnicity, and mortality data, from a large US health plan were utilized to identify individuals with ≥1 inpatient claim with a diagnosis code for HF (1 January 2008–30 September 2012). Study variables were analyzed using descriptive and multivariable approaches to identify patient/clinical characteristics associated with post-discharge outcomes.

Main outcome measures: Primary outcomes included post-discharge mortality and readmission.

Results: A total of 126,214 individuals were identified with a HF-related hospitalization; 19.1% with data to calculate chronic kidney disease (CKD) stage. For the overall sample, mortality probability was 4.9% and 13.4% at 1 and 6 months post-discharge, respectively (4.5% and 12.4% for subset with calculated CKD stage), while readmission (all-cause) probability was 14.8% and 39.6% at 1 and 6 months post-discharge, respectively (18.4% and 44.5% for subset with calculated CKD stage). Within the subset with calculated CKD stage, mortality and readmission probabilities differed by CKD stage (p < 0.001), with decreased renal function corresponding with increased risk of mortality and readmission. After multivariable adjustment, increasing age was associated with increased risk of mortality, while advancing CKD stage, various index hospitalization variables (i.e., pre-admission emergency room visit, intensive care unit during hospitalization), and baseline all-cause hospitalization were associated with both increased risk of mortality and all-cause 1 month readmission.

Conclusions: Calculated CKD, various index hospitalization variables, and baseline all-cause hospitalization were associated with increased risk of mortality and all-cause 1 month readmission among patients hospitalized with HF. Risk of post-discharge readmission and mortality increased with worse renal function, suggesting that improved management of this subset may reduce the burden and cost of this disease. Key study limitations include those related to retrospective claims-based studies and that renal function data were available for a subset of study patients.

Keywords:

• Heart failure
• chronic kidney disease
• hospitalization
• readmission
• mortality

Transparency

Declaration of funding

This study was supported by Novartis Pharmaceuticals Corp., East Hanover, NJ, USA.

Declaration of financial/other relationships

J.P.S., L.B., C.B.-P., and A.A. have disclosed that they are employees of Optum Inc., a company that received funding from Novartis to help conduct this study. W.C. and K.W.J. have disclosed that they are employees of Novartis Pharmaceuticals Corp.

CMRO peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgments

Medical writing support was provided by Tara Cowling MSc of Medlior Health Outcomes Research Ltd., and Frank G. Bottone Jr. PhD, of Scriptorium Medical Medica Writing Inc.

Previous presentations: Chan W, Swindle JP, Waltman Johnson K, et al. Post-discharge costs in heart failure: kidney disease severity as a key contributor. Poster session presented at: American Heart Association Quality of Care and Outcomes Research Scientific Sessions, 2–4 June 2014, Baltimore, MD, USA. Riedel A, Waltman Johnson K, Chan W, et al. Health outcomes among US managed care enrollees hospitalized with acute heart failure: variations based on age and comorbid atrial fibrillation. Poster session presented at: American Heart Association Scientific Sessions, 16–20 November 2013, Dallas, TX, USA. Swindle J, Chan W, Waltman Johnson K, et al. Renal impairment in acute heart failure: insights from a managed care database. Poster session presented at: American Heart Association Scientific Sessions, 16–20 November 2013, Dallas, TX, USA. Swindle J, Waltman Johnson K, Chan W, et al. Hospitalization characteristics of renally impaired patients admitted with heart failure. Poster session presented at: American College of Cardiology Scientific Session, 29–31 March 2014, Washington, DC, USA.