This study was sponsored by Amgen through a contract to the Kaiser Permanente Northwest Center for Health Research. The contract guaranteed publication rights to the authors. Amgen had the right to review and comment on the paper, but the study design, analysis, interpretation, writing and final decisions over content rested with the investigators, not the sponsor. The manuscript contains analyses of the costs and natural history of heart failure. The work is not product-specific as no pharmaceutical agents or other medical products are compared or described. The authors declare that they have no competing interests.
DS, EJ, MT, DB and KC participated in the design of the study and interpretation of analyses. DB carried out the statistical analysis. XY and AP extracted data from KPNW files and participated in the interpretation of the analysis. DS and EJ drafted the manuscript, and all authors read and approved the final manuscript.
Identifying heart failure patients most likely to suffer poor outcomes is an essential part of delivering interventions to those most likely to benefit. We sought a comprehensive account of heart failure events and their cumulative economic burden by examining patient characteristics that predict increased cost or poor outcomes.
We collected electronic medical data from members of a large HMO who had a heart failure diagnosis and an echocardiogram from 1999–2004, and followed them for one year. We examined the role of demographics, clinical and laboratory findings, comorbid disease and whether the heart failure was incident, as well as mortality. We used regression methods appropriate for censored cost data.
Of the 4,696 patients, 8% were incident. Several diseases were associated with significantly higher and economically relevant cost changes, including atrial fibrillation (15% higher), coronary artery disease (14% higher), chronic lung disease (29% higher), depression (36% higher), diabetes (38% higher) and hyperlipidemia (21% higher). Some factors were associated with costs in a counterintuitive fashion (i.e. lower costs in the presence of the factor) including age, ejection fraction and anemia. But anemia and ejection fraction were also associated with a higher death rate.
Close control of factors that are independently associated with higher cost or poor outcomes may be important for disease management. Analysis of costs in a disease like heart failure that has a high death rate underscores the need for economic methods to consider how mortality should best be considered in costing studies.