Health-related quality of life and predicting survival in cancer: not a simple matter

Excerpt

The wish to know what the future holds must be as old as the development of self-consciousness in mankind. When we are faced with uncertainties in life, particularly as related to an illness, we wish to know how to predict the course of our illness and its eventual outcome. Although we will generally turn to our physicians or other health care professionals for reassurance and a prognosis, it seems that self-rating our health also provides meaningful predictions of mortality and length of survival. Numerous studies have been published on the value of self-rated health (SRH) as a predictor of mortality after discounting other health status indicators and relevant covariates known to predict mortality [18, 20]. In the general population, self-rated global health is a strong predictor of survival and is associated with socioeconomic status and educational level, whereas gender and race/ethnicity appear to act separately [15]. However, there are several controversies. For example, the role of depression is not clear; it apparently was predictive in some studies and not in others [13, 17, 22]. In a study of 1,355 Israeli men and women, SRH appeared to be predictive of mortality in the short-term (within 4 years of death), but not in the longer term, and the association was stronger in an older age group (ages 85–94) than in younger people [1]. The effect of gender is controversial, with some studies claiming that the association is stronger in men than women [19] and others that it is the opposite [1]. In another study, the effect of gender apparently disappeared by late adulthood [21]. These examples illustrate the complexity of studying the association of SRH and mortality; many factors must be accounted for in the analyses. Nevertheless, the association between SRH and mortality seems to be true not only for the general population but also for many diseases, e.g., diabetes, infectious and respiratory diseases, heart disease, stroke, and cancer [2]. …