Patients with heart failure often overestimate life expectancy

Many patients with heart failure have survival expectations that are significantly greater than clinical predictions, with younger patients and those with more severe disease more likely to overestimate their remaining life span, according to a study in the June 4 issue of JAMA.

Heart failure accounts directly for 55,000 deaths and indirectly for an additional 230,000 deaths in the United States each year. Despite advances in care, the prognosis for patients with symptomatic heart failure remains poor, with median (50 percent of patients still alive) life expectancy of less than 5 years, according to background information in the article. For those with the most advanced disease, 1-year mortality rates approach 90 percent. Prognosis is dependent on various patient characteristics, and a number of prognostic models have been developed to help predict survival in patients with heart failure.

The extent to which patients with heart failure understand their prognosis is not clear. “Patient perception of prognosis is important because it fundamentally influences medical decision making regarding medications, devices, transplantation, and end-of-life care,” the authors write.

Larry A. Allen, M.D., M.H.S., of the Duke Clinical Research Institute, Durham, N.C., and colleagues conducted a study to determine the personal predictions of life expectancy of 122 patients with heart failure (who were not bed-ridden) and compared those with each of their model-estimated life expectancy predictions. The patients (average age 62 years; 47 percent African American; 42 percent New York Heart Association [NYHA] class III or IV [more severe heart failure]) were surveyed regarding their predicted life expectancy. Model-predicted life expectancy was calculated using the Seattle Heart Failure Model (SHFM).

On average, patients overestimated their life expectancy relative to model-predicted life expectancy (median patient-predicted life expectancy, 13.0 years; model-predicted expectancy, 10.0 years). The majority of patients (77 [63 percent]) overestimated their life expectancy when compared with that predicted by the SHFM. The median life expectancy ratio (LER; i.e., ratio of patient-predicted to model-predicted life expectancy) was 1.4, meaning the median overestimation of predicted future survival in the population was 40 percent. There was no association between higher LER and improved survival. Thirty-five patients (29 percent) died over a median follow-up period of 3.1 years.

There was little relationship between patient-predicted and model-predicted life expectancy. Patient predictions of life expectancy were more similar to those predicted by empirically derived actuarial life tables based on age and sex alone, without regard for the presence of heart failure. Patient characteristics that were predictive of overestimation of life expectancy included younger age, more severe disease and less depression.

“The exact reasons for this incongruity are unknown but they may reflect hope or may result from inadequate communication between clinicians and their patients about prognosis. Because differences in expectations about prognosis could affect decision making regarding advanced therapies and end-of-life planning, further research into both the extent and the underlying causes of these differences is warranted. Whether interventions designed to improve communication of prognostic information between clinicians and patients would improve the process of care in heart failure should be tested in appropriately designed clinical trials,” the authors conclude.

(JAMA. 2008;299[21]:2533-2542. Available pre-embargo to the media at www.jamamedia.org)

Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

In an accompanying editorial, Clyde W. Yancy, M.D., of the Baylor University Medical Center, Dallas, writes that questions remain regarding the accuracy of clinical prediction models.

“Currently, there is insufficient precision in the prognostication of heart failure, and decision making at the end of life is perhaps the most personalized of all decision making in medicine. Although well-intended and carefully constructed tools and awareness of the natural history of disease are helpful, it is the primacy of the patient-physician interface that must prevail. Until these questions are fully addressed, it is best to avoid adopting an imprecise method, instead continuing to embrace the individualized decision-making process guided by physician judgment that incorporates all patient care considerations.”

(JAMA. 2008;299[21]:2566-2567. Available pre-embargo to the media at www.jamamedia.org)

Editor’s Note: Please see the article for additional information, including financial disclosures, funding and support, etc.