Association of anemia with health-related quality of life and survival: a large population-based cohort study

Abstract

Anemia is highly prevalent, especially in older individuals. In selected populations, anemia has been reported to be associated with impaired survival and health-related quality of life. However, data on this impact in the general population are rare. Furthermore, discussions on the optimal definition of anemia have not been conclusive. We investigated these issues using survival data, scores from a health-related quality of life questionnaire (RAND-36), and hemoglobin concentration from 138670 subjects, aged 18-93 years, participating in the Lifelines cohort. Anemia was defined according to World Health Organization criteria and was further subclassified in participants over 60 years old. Anemia was present in 5510 (4.0%) of all 138670 subjects and 516 (2.8%) in the 18667 individuals older than 60 years. Anemia had no impact on overall survival and limited impact on health-related quality of life in individuals less than 60 years old. In contrast, in individuals over 60 years old anemia significantly impaired overall survival and health-related quality of life. The lower health-related quality of life was mainly observed in subscales representing physical functioning. Although consensus on the subclassification of anemia is lacking, our data suggest that particularly anemia of chronic inflammation was associated with worse overall survival and decreased health-related quality of life. Multivariate models confirmed that anemia was an independent risk factor for decreased health-related quality of life in older individuals. Finally, women with a hemoglobin concentration between 12.0-13.0 g/dL (considered anemia in men, but not in women) experienced a significantly lower health-related quality of life. This large, prospective, population-based study indicates that anemia is associated with worse overall survival and health-related quality of life in older individuals, but not in younger individuals. The findings of this study challenge the definition of anemia in women over 60 years old, and suggest that the optimal definition of anemia, in the perspective of health-related quality of life, in women over 60 years old should be altered to a hemoglobin concentration below 13.0 g/dL (8.0 mmol/L), which is comparable to that in men.

Figure 1.

Prevalence of anemia and overall survival in individuals younger and older than 60 years. (A) The prevalence of anemia as a function of sex and age. (B) Overall survival of non-anemic and anemic individuals younger than 60 years. (C) Overall survival of non-anemic and anemic individuals older than 60 years.

Figure 2.

Percentages of individuals, divided according to age group, with scores below the sex- and age-specific cut-off values for the different subscales of the RAND-36 health survey. An asterisk indicates a significantly (P-value <0.01) larger percentage below the sex- and age-specific cut-off value in anemic individuals compared with non-anemic individuals. PF: physical functioning; SF: social functioning; RF: physical role functioning; RE: emotional role functioning; MH: mental health; VT: vitality; BP: bodily pain; GH: general health.

Figure 3.

Kaplan-Meier curves of survival of individuals with different types of anemia.

Figure 4.

Risk of having a lower total health-related quality of life score than the (sex- and age-specific) 25^th percentile cut-off according to hemoglobin concentrations. The red rectangles indicate a hemoglobin concentration below the currently used World Health Organization definition of anemia. 95% CI: 95% confidence interval.