Types of anemia and mortality among older disabled women living in the community: the Women's Health and Aging Study I

Abstract

Aims: To classify the different types of anemia among moderately to severely disabled women living in the community and examine the relationship between types of anemia and mortality.

Methods: We studied anemia in 688 women, >or=65 years, in the Women's Health and Aging Study I, a population based study of moderately to severely disabled older women living in the community in Baltimore, Maryland. Anemia was defined by World Health Organization criteria. Causes of anemia were classified as due to nutritional deficiencies (iron, folate, and B12 deficiencies), anemia of chronic inflammation, anemia with renal disease, and unexplained anemia.

Results: 147 of 688 (21.4%) women were anemic (hemoglobin <12 g/dL). Of the 147 anemic women, 22 (15.0%) had anemia due to nutritional causes, 45 (30.6%) had anemia due to chronic inflammation, 29 (19.7%) had anemia and renal disease, and 51 (34.7%) had unexplained anemia. The proportions of those who died over five years among non-anemic women and women with anemia due to nutritional causes, chronic inflammation, renal disease, and unexplained anemia were 26.1%, 18.2%, 38.6%, 64.3%, and 33.3%, respectively (p<0.0001). Compared with non-anemic women, those with anemia and renal disease (HR 1.99, 95% CI 1.18-3.35, p=0.009) and anemia of chronic inflammation (HR 1.69, 95% CI 1.00-2.84, p=0.05) had higher risk of death.

Conclusions: Anemia is common among moderately to severely disabled older women living in the community, and about one-third of the anemia is unexplained. Anemia with renal disease and anemia of chronic inflammation are associated with a higher mortality.

Fig. 1. Classification of anemia among women in the Women's Health and Aging Study I

Fig. 2. Five-year survival of women in the Women's Health and Aging Study I by anemia status