Chronic Disease: Life Expectancy vs Survival Rate
Patients with chronic diseases may have life expectancy rates that exceed predicted survival rates for these diseases
Patients with chronic disease—including chronic obstructive pulmonary disease (COPD), heart failure, end-stage renal failure, and chronic kidney disease—may have perceived life expectancy rates that differ from the predicted survival rate for these diseases, researchers reported in BMJ Open.
Drs Barnaby Hole, from Southmead Hospital, and Joseph Salem, from the University of Bristol, UK, evaluated what is known about how long patients with non-cancer chronic disease expect to live and how these estimates compare with other methods of predicting survival and measured outcomes.
The researchers used a systematic search of 6837 documents containing information about patient life expectancy. Nine documents from the UK, Netherlands, and United States contained the pre-specified criteria for inclusion. A total of 729 participants were included: 573 identified with heart failure, 89 had COPD, 62 had end-stage renal failure, and 5 had chronic kidney disease. Study sizes ranged from 20 to 135 patients. The mean age of participants ranged from 58 to 75.
The most common measure of life expectancy was in the form of interviews with participants. Patients were asked to indicate how long they expected to live by selecting from vignette answers, giving a verbal response, and/or by using a Visual Analogue Scale. Self-estimates of life expectancy were compared with predictions from clinical risk calculators, clinician-estimated life expectancy, and observed survival. Follow-up periods ranged from 1 to 3 years, and the majority of patients were alive at the end of the studies.
Overall, self-estimated life expectancy exceeded observed survival. Among patients with heart failure, median self-estimated life expectancy was 40% longer than predicted by a validated model. Outpatients receiving hemodialysis for chronic kidney disease were more optimistic about prognosis than their nephrologists and overestimated their chances of surviving 5 years. Patients with heart failure and COPD were approximately 3 times more likely to die in the next year than they predicted. The only example of self-estimated life expectancy consistent with survival was 1-year mortality in patients with ESRF.
The study shows that individuals with chronic disease may have unrealistically optimistic expectations of their prognosis, according to the authors, who noted that these expectations might lead some patients to make health decisions and life choices that they would not if their predictions were more realistic. According to the researchers, “A better understanding is needed of the interaction between survival expectations and behavior in chronic disease.”
- Hole B, Salem J. How long do patients with chronic disease expect to live? A systematic review of the literature. BMJ Open. 29 December 2016. doi: 10.1136/bmjopen-2016-012248.