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Article Excerpt
Research shows that anemia in the older adult is a common problem as the prevalence of the disease increases with each decade of life once individuals reach age 70 (Beghe, Wilson, & Ershler, 2004; Bhat, Kirmani, & Raw, 2008; Guralnik, Ershler, Schrier, & Picozzi, 2005). From 2000 to 2004, anemia was the cause of death for about 10% of Americans age 65 and older, or over 3.6 million persons (National Center for Health Statistics [NCHS], 2007). With the size of the aging population expected to more than double, reaching 71.5 million by 2030 (MetLife Mature Market Institute, 2008), the prevalence of anemia is likely to increase substantially in the near future. Anemia in the older adult has been reported to have reached crisis levels as anemia is associated with changes in the quality of life, decreased cognition and functional ability, and an increased risk for falls, infections, morbidity, and mortality (Bhat et al., 2008; Guralnik et al., 2005). The prevalence, etiology, classification, and diagnosis of anemia in older adults are reviewed and collaborative interventions identified for its management.
Prevalence
Research investigating the prevalence of anemia in older adults has shown mixed results due to variations in study designs, sample size, population characteristics, and even criteria used to define anemia. The majority of studies (Beghe et al., 2004; Dharmarajan, Avula, & Norkus, 2006) use hemoglobin concentration to define anemia, with separate threshold values for women and men as established by the World Health Organization (WHO) (<12.0 g/dL for women and <13.0 g/dL for men) (Beghe et al., 2004; Dharmarajan et al., 2006). Hematocrit values, alone or along with hemoglobin concentration, also were used to assess anemia's prevalence (Beghe et al., 2004; Thomas, 2004). Study populations also vary, with some healthy and living at home and others living in institutionalized settings (Guralnik, Eisenstaedt, Ferrucci, Klein, & Woodman, 2004). In spite of these variations, however, consistent patterns have emerged.
A systematic review of 71 studies investigating the prevalence of anemia in adults age 65 and older, found the prevalence of the disease to be 3.3%-41% among women and 2.9%-61% among men (Beghe et al., 2004). The wide range found in this study illustrates the difficulty with absolute assessment of prevalence of anemia among older adults. The most unswerving finding of this systematic review was the strong positive relationship of anemia with age: the higher the age, the higher the prevalence of the disease. The greatest prevalence occurred after age 85, when individuals have anemia 2-3 times more often than the younger cohorts. In addition, the highest rates for both men and women occurred among hospitalized older adult in acute-geriatric units, and those living in institutional settings such as nursing homes. By contrast, the lowest rates were among those living independently.
The most comprehensive studies investigating the prevalence of anemia in older adults were reported by Guralnik and colleagues (2004, 2005). Both studies used data from the Third National Health and Nutrition Examination Survey (NHANES) (NCHS, 1996). The original NHANES III data (Guralnik et al., 2004) were obtained from 39,695 persons, 5,252 of whom were community-dwelling persons age 65 and older. Blood tests identified anemia using the hemoglobin results defined by WHO. Data on co-morbidities, race, gender, and ethnicity also were collected. This large study found the overall prevalence of anemia in the population age 65 or older to be 10.6%, with a prevalence of 11% for men and 10.2% for women. The slightly higher overall prevalence of anemia in men was attributed to the higher threshold set for them. More significant, however, was the pronounced increase in the prevalence of anemia by age; among those age 85 and older, 26% of men and 20% of women (see Figure 1) were anemic, a disparity that continues into advanced age brackets. Moreover, substantial differences existed in the prevalence of anemia by race and ethnicity: non-Hispanic Whites 9%, Mexican-Americans 10.4%, and non-Hispanic Blacks 27.8%, nearly a three-fold increase in this group (see Table 1). Other researchers corroborated these findings in ethic differences. In their sample of 1,744 men and women age 71 or older and living at home, Denny, Kuchibhatla, and Cohen (2006) found that anemia was three times more prevalent among African Americans than their Caucasian counterparts. Other similar results also had been reported (Salive et al., 1992). In summary, studies show that anemia is more prevalent among those over age 70, are male, are non-Hispanic Blacks, and live in institutional settings.
Etiology and Pathophysiology
Three broad etiologies of anemia in the older adult have been proposed (Guralnik et al., 2004; Joosten et al., 1992). These are anemias due to blood loss/nutritional deficiencies, anemias due to chronic illness/inflammation or chronic kidney disease (CKD), and those due to unexplained etiologies.
Anemias due to blood loss/nutritional deficiencies. This type of anemia in older adults accounts for 34% of all the cases (Guralnik et al., 2005; Spivak, 2000) and is related to either insufficiency of raw material to produce erythrocytes or excessive loss of the erythrocytes. Nutritional deficiencies are...
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