Prevalence of anemia in hospitalized internal medicine patients: Correlations with comorbidities and length of hospital stay

Background: Several studies have documented a linear growth of the prevalence of anemia with aging. Especially in hospitalized elderly patients, anemia can aggravate the course of chronic disorders, and ultimately get worse the clinical outcomes. Methods: To evaluate the distribution, the main causes, and the possible correlations of anemia with comorbidities and length of hospitalization in a population of internal medicine inpatients, we carried out an observational study on a cohort of 923 consecutive admissions relative to 856 subjects. Results: Anemia was observed in 58.4% of patients, with an increase of the prevalence with increasing age regardless gender difference. In more than one-half of anemic patients, anemia was mild. Chronic inflammation and chronic renal failure were the most frequent causes of anemia in our population, and in > 35% of patients a multifactorial anemia was diagnosed. Age, chronic renal failure, chronic liver disease, hematological malignancies, solid tumors, and antiplatelet therapy showed a significantly independent association with the presence of anemia. Hemoglobin levels were influenced by the presence of chronic lung disease, chronic renal failure, hematological malignancies, solid tumors, and antiplatelet therapy. The presence and the degree of anemia also correlated with a significantly longer hospital stay. Conclusions: Our data confirm the high prevalence of anemia in patients hospitalized in an Internal Medicine Department, with a remarkable burden of mild forms, and of chronic inflammation's pathogenic mechanism. Correlations with comorbidities and duration of hospital stay highlight the crucial part played by anemia in determining the clinical complexity of such patients.