Heart failure patients who are still mobile typically estimate that they will live three years longer than standard models predict they will, according to a report in the Journal of the American Medical Association.
“Because differences in perceived survival could affect decision making regarding advanced therapies and end-of-life planning, the causes of these discordant predictions warrant further study,” Dr. Larry A. Allen, from the Duke Clinical Research Institute in Durham, North Carolina, and colleagues conclude.
“Prior studies have looked at end of life issues in heart failure,” Allen told Reuters Health, “but few have looked specifically at the patients’ perceptions of their chances for survival; and none have looked at how patients’ predictions compare (with) statistically based model predictions.”
The new study involved a survey of 122 patients in the Duke Heart Failure Disease Management Program. The subjects were interviewed between July and December 2004 and followed through February 2008.
The average patient age was 62 years and 47 percent of subjects were African American, the report indicates. All of the patients had New York Heart Association class III or IV heart failure, indicating advanced disease.
The average patient-predicted life expectancy was 13 years, while the statistical model predicted that life expectancy was only 10 years. Factors associated with overestimating life expectancy included younger age, increased NYHA class, lower ejection fraction, and less depression.
“Not surprisingly, patients on average predicted that they would live longer than the models predicted,” Allen said. ”Surprisingly, patients with advanced heart failure predicted they would live the same amount of time as patients with mild heart failure, despite the fact that heart failure severity is one of the strongest predictors of life expectancy.”
Twenty-nine percent of patients died during an average follow-up period of 3.1 years, the report indicates. No association was seen between overestimations of survival and actual survival.
This “provocative” study identifies a disconnection between patient-predicted and statistical model-predicted life expectancy among ambulatory patients with heart failure,” Dr. Clyde W. Yancy, from Baylor University Medical Center in Dallas, comments in a related editorial.
In so doing, the study presents challenges to physicians in evaluating the patient’s need to know the prognosis; communicating prognostic information; and anticipating the consequences of such information for a patient with heart failure.