Association of mild anemia with hospitalization and mortality in the elderly: the Health and Anemia population-based study

1 Laboratory of Geriatric Neuropsychiatry, Istituto di Ricerche Farmacologiche "Mario Negri", Milan 2 Laboratory for Medical Research & Consumer Involvement, Istituto di Ricerche Farmacologiche "Mario Negri", Milan 3 Laboratory of Translational and Outcome Research in Oncology, Istituto di Ricerche Farmacologiche "Mario Negri", Milan 4 Laboratory of Analysis, Ospedale degli Infermi, Biella 5 County Cancer Registry, Local Health Authority, ASL BI, Biella 6 Department of Oncology, Ospedale degli Infermi, Biella 7 Department of Medicine & Geriatrics, Ospedale degli Infermi, Biella 8 Community Medicine, Local Health Authority, ASL BI, Biella, Italy Correspondence: Ugo Lucca, Laboratory of Geriatric Neuropsychiatry, Istituto di Ricerche Farmacologiche "Mario Negri", via La Masa 19, 20156 Milano, Italy. E-mail: lucca{at}marionegri.it Background: Mild anemia is a frequent laboratory finding in the elderly usually disregarded in everyday practice as an innocent bystander. The aim of the present population-based study was to prospectively investigate the association of mild grade anemia with hospitalization and mortality. Design and Methods: A prospective population-based study of all 65 to 84 year old residents in Biella, Italy was performed between 2003 and 2007. Data from a total of 7,536 elderly with blood tests were available to estimate mortality; full health information available to evaluate health-related outcomes was available for 4,501 of these elderly subjects. Mild grade anemia was defined as a hemoglobin concentration between 10.0 and 11.9 g/dL in women and between 10.0 and 12.9 g/dL in men. Results: The risk of hospitalization in the 3 years following recruitment was higher among the mildly anemic elderly subjects than among subjects who were not anemic (adjusted hazard ratio: 1.32; 95% confidence interval: 1.09–1.60). Mortality risk in the following 3.5 years was also higher among the mildly anemic elderly (adjusted hazard ratio: 1.86; 95% confidence interval: 1.34–2.53). Similar results were found when slightly elevating the lower limit of normal hemoglobin concentration to 12.2 g/dL in women and to 13.2 g/dL in men. The risk of mortality was significantly increased in mild anemia of chronic disease but not in that due to β-thalassemia minor. Conclusions: After controlling for many potential confounders, mild grade anemia was found to be prospectively associated with clinically relevant outcomes such as increased risk of hospitalization and all-caus