Transferrin Saturation and Hospital Length of Stay and Mortality in Medicare Beneficiaries


Address correspondence to Arch G. Mainous III, Department of Family Medicine, Medical University of South Carolina, 295 Calhoun St., Charleston, SC 29425. E-mail:



To evaluate in a large, nationally representative cohort the association between high serum transferrin saturation (TS) and hospital length of stay and mortality in older adults.


Prospective cohort.


Longitudinal analyses of the Third National Health and Nutrition Examination Survey linked to Medicare claims from 1991 through 2006.


Medicare beneficiaries aged 65 and older at baseline.


Transferrin saturation collected on each participant at baseline was characterized as <20.0%, 20.0% to 54.9%, and 55.0% and greater. Length of stay in the hospital and death in the hospital were primary outcomes. Analyses were adjusted for age, sex, race and ethnicity, education, and severity of illness.


Individuals hospitalized during the study period (79.4%) with high (odds ratio (OR) = 2.54, 95% confidence interval (CI) = 1.05–6.12) or low (OR = 1.31, 95% CI = 1.07–1.62) TS had a significantly greater risk of death than those with moderate TS. Individuals with high TS had longer average length of stay per hospitalization (11.1 days, (standard error, SE 1.7 days), P = .01) than those with moderate TS (8.4 (0.3) days). Individuals with high TS also had more hospital days per year (8.6 (2.0) days, P = .04) than those with moderate TS (6.7 (0.5) days).


High TS is associated with longer length of stay and death in the hospital (unweighted N = 3,847, weighted N = 28,395,464).