Undernutrition and risk of mortality in elderly patients within 1 year of hospital discharge

Background. The importance of undernutrition as a determinant of postdischarge mortality among hospitalized elderly people remains controversial. The purpose of this study was to investigate this issue. Methods. The study included 660 elderly patients (85% white, 98% men, average age 73 [+ or -] 6 years) discharged from a university-affiliated Department of Veterans Affairs Hospital, who were followed for 1 year. Associations between patient characteristics at hospital discharge and mortality were identified utilizing Cox Proportional Hazards Regression analysis. Results. In the year following hospital discharge, 85 subjects (13%) died. After adjusting for illness severity (Acute Physiology and Chronic Health Evaluation II score) and functional status (Katz Index of Activities of Daily Living score), a body mass index (BMI) [less than or equal to] 20 kg/[m.sup.2] was strongly associated with mortality (adjusted relative risk, [95% confidence interval] 1.83 [1.17-2.85]), as was more than 10% weight loss in the prior year (2.31 [1.35-3.94]), and weight as percent of usual weight (WPU) [less than or equal to] 85% (1.78 [1.14-2.77]). Albumin [less than or equal to] 30 g/l was only weakly associated with mortality (1.10 [0.67-1.81]). When all of the putative nutrition variables were included in a multivariable analysis with the two control variables, only BMI followed by WPU [less than or equal to] 85% entered the model. Utilizing this model, the predicted probabilities of death at 1 year were calculated for the study subjects and for a hypothetical group of patients who were identical to the study subjects except they were assigned a BMI of 28 kg/[m.sup.2] and their WPU was 100%. Compared to 24% of the actual subjects, only 7% of the hypothetical well-nourished patients would have been classified as being at high risk for mortality (a 71% relative reduction). Conclusions. Older patients who have evidence of chronic body mass depletion are at significantly increased risk of mortality within the year following hospital discharge.