Change in Comorbidity Prevalence with Advancing Age Among Persons with Heart Failure

BACKGROUND: Comorbidity-a condition that co-exists with a primary illness-is common among older persons with heart failure and can complicate the overall management of this population. OBJECTIVES: To determine the relationship between advancing age and the prevalence and patterns of comorbidity among older persons with heart failure. DESIGN: Retrospective longitudinal cohort study PARTICIPANTS: A total of 201,130 Medicare beneficiaries with heart failure stratified into three age strata in 2001: 66-75, 76-85, and 86+ years, and followed over 5 years. MEASUREMENTS: (1) Prevalence of 19 conditions as identified by the Chronic Conditions Warehouse from Medicare claims data, characterized as concordant (related to heart failure) or discordant (unrelated to heart failure), and (2) overall comorbidity burden, defined as count of conditions. RESULTS: The median number of comorbidities rose from four (IQR: 2-5) to five (IQR: 4-7) among the young-old, and from 4 (IQR: 3-6) to 6 (IQR: 5-8) among the middle-old and oldest-old between 2001 and 2006. In 2001, the majority of concordant conditions were more prevalent among the youngest than oldest beneficiaries (e.g., diabetes 46.2% vs 26.9%; kidney disease 21.8% vs 18.4%), while the majority of discordant conditions were more prevalent among the oldest-old than youngest-old beneficiaries (e.g., dementia 39.6% vs 9.9%; hip fracture 9.5% vs 1.9%). Discordant conditions increased in prevalence faster among the oldest than youngest beneficiaries (e.g., dementia 13% points versus 9% points). CONCLUSION: Among older Medicare beneficiaries with heart failure, there is a higher overall burden of comorbidity and greater prevalence of discordant comorbidity among the oldest old. Comorbidity prevalence increases over time, with discordant comorbidity increasing at the fastest rate among the oldest old. This comorbidity burden highlights the challenge of effectively treating heart failure while simultaneously managing co-existing and unrelated conditions.