Racial variation in the relationship of anemia with mortality and mobility disability among older adults

Abstract

Anemia is more common among older blacks than older whites. However, it is unclear whether anemia predicts adverse events similarly in both races. Data on 1018 black and 1583 white adults aged 71 to 82 years were analyzed. Anemia, as defined by World Health Organization (WHO) criteria, was used to predict mortality over 6 years and incidence of mobility disability over 4 years. In proportional hazards models of mortality in whites, the age-adjusted hazard ratio (HR) for anemia in men was 1.96 (95% confidence interval [CI]: 1.35, 2.83) and in women was 2.86 (95% CI: 1.69, 4.82). In contrast, anemia was not associated with mortality in black men (HR = 1.15 [95% CI: 0.77, 1.72]) or women (HR = 1.39 [95% CI: 0.91, 2.14]). Higher mortality rate was observed only in black men with hemoglobin values more than 20 g/L (2.0 g/dL) below the WHO cutoff, whereas mortality rates were elevated in white men with hemoglobin values 1 to 10, 11 to 20, and more than 20 g/L below the WHO cutoff. In conclusion, anemia was significantly associated with increased risk of death and mobility disability in community-dwelling older whites. Conversely, older blacks classified as anemic by WHO criteria were not at risk for adverse events, indicating that alternative criteria are warranted.

Figure 1

Kaplan-Meier survival curves by WHO-defined anemia status among race-sex subgroups of older adults.

Figure 2

Cumulative incidence of mobility disability by WHO-defined anemia status among race-sex subgroups of older adults.