Abstract and Introduction
Background: there is little research how older people's will-to-live predicts their survival.
Objective: to investigate how many years home-dwelling older people wish to live and how this will-to-live predicts their survival.
Methods: as a part of the Drugs and Evidence-Based Medicine in the Elderly (DEBATE) study, 400 home-dwelling individuals aged 75–90 were recruited into a cardiovascular prevention trial in Helsinki. In 2000, a questionnaire about the wishes of their remaining life was completed by 283 participants. Participants were inquired how many years they would still wish to live, and divided into three groups according to their response: group 1: wishes to live <5 years, group 2: 5–10 years, group 3: >10 years. Mortality was confirmed from central registers during a 10-year follow-up. The adjusted Cox proportional hazard model was used to determine how will-to-live predicted survival.
Results: in group 1 wishing to live less than 5 years, the mean age and the Charlson comorbidity index were the highest, and subjective health the poorest. There were no differences between the groups in cognitive functioning or feeling depressed. Mortality was the highest (68.0%) among those wishing to live <5 years compared with those wishing to live 5–10 years (45.6%) or over 10 years (33.3%) (P < 0.001). With group 1 as referent (HR: 1.0) in the Cox proportional hazard model adjusting for age, gender, Charlson comorbidity index and depressive feelings, HR for mortality was 0.66 (95% CI: 0.45–0.95) (P = 0.027) and 0.47 (95% CI: 0.26–0.86) (P = 0.011) in groups 2 and 3, respectively.
Conclusion: the will-to-live was a strong predictor for survival among older people irrespective of age, gender and comorbidities.
Will-to-live (WTL) has been defined as a psychological expression of the striving for life, including both rational and instinctual underpinning. WTL is a person's subjective perception and it can be described only by the individual experiencing it. It depends on meaningfulness and quality of life as well as motivation and other less rational instincts. The loss of WTL is an entity distinct from depression, despair, grief or sadness. A person may suffer from severe depression but WTL may be strong.
The concept of WTL has connections with such concepts as subjective life expectancy or self-rated health (SRH). However, there are also distinctions between these concepts. Subjective life expectancy has been shown to correspond well with actuarial estimates of survival. However, subjective life expectancy is an estimation of the length of own life having a rational base, whereas WTL may include more motivational dimensions. When estimating their subjective life expectancy, many people judge their possibilities to longevity according to their parents' length of life.[6,7] For decades, several follow-up studies all over the world have found that SRH is a strong predictor of survival.[5,8–10] The origins of SRH lie in an active cognitive process combining numerous aspects of clinical, physiological, functional and, to a smaller extent, psychological dimensions of health. SRH reflects a person's evaluation of his/her current state of health. Although it has been shown to predict survival, the subject does not per se evaluate life expectancy. In WTL, evaluations of one's own health, estimation of individual life expectancy and motivation and current quality-of-life may have influence on the years a person wants to live.
WTL has been studied among cancer and HIV patients, and among patients in palliative care approaching death.[11–13] The focus of these studies has mainly been on how final stages of illness, its symptoms and psychosocial aspects have effect on WTL among dying patients,[11,12,14,15] or how very ill, hospitalised patients would trade off time to better quality of life. However, recently WTL has also been explored at the population level among healthy older people as a construct affecting the length of life.
The predictors and associates of WTL have been explored in a few studies.[1,2] During terminal illness certain symptoms, such as depression, anxiety, shortness of breath and sense of well-being, were associated with WTL. In addition, feelings of hopelessness, being burden to others and dignity were associated with WTL among patients approaching death. Social aspects such as satisfaction with social support from family, friends and health-care providers may play an important role in WTL. Also religious patients seem to sustain a high WTL during a terminal illness.[14,16] However, less is known about the associates of WTL among healthy older populations. Carmel showed that strong WTL is associated with male gender, younger age, having less symptoms, living with a partner, high self-esteem and fear of death.
One study has showed that WTL predicts survival among 70+ women at a population level, but we are aware of no other longitudinal prospective trials concerning WTL and survival among older people. We investigated this in our cohort aged 75–90 years and living independently at the baseline.
Age Ageing. 2012;41(6):789-794. © 2012 Oxford University Press
Copyright 2007 British Geriatrics Society. Published by Oxford University Press. All rights reserved.