Protein-Energy Undernutrition and the Risk of Mortality Within Six Years of Hospital Discharge

Abstract

Objective: The primary objective was to determine whether protein-energy undernutrition among elderly patients discharged from the hospital remains a significant risk factor for mortality beyond 1 year.

Design: Prospective Survey (cohort study).

Setting: Outpatient follow-up of patients discharged from a Geriatric Rehabilitation Unit (GRU) of a Veterans Administration hospital.

Participants: Of 350 randomly selected admissions to the GRU, 322 were discharged alive from the hospital. These 322 patients represented the study population of whom 99% were male, and 75% were white. The average age of the study patients was 76 (range 58 to 102) years.

Measurements: At admission and again at discharge, each patient completed a comprehensive medical, functional, neuro-psychological, socioeconomic, and nutritional assessment. Subsequent to discharge, each subject was tracked for an average of 6 years. In addition to including serum albumin and other putative nutrition indicators in the data set, a “nutrition-risk” indicator variable was created. Subjects were stratified into the nutrition “high-risk” group if their albumin was less than 30 g/L or BMI was less than 19; and, “low-risk” group if albumin was equal to or greater than 35 g/L and BMI equal to or greater than 22. All others represented the “moderate-risk” group.

Results: Within the 6-year post-hospital-discharge follow-up period, 237 study subjects (74%) died. Based on the Cox proportional hazards survival model, the variable most strongly associated with mortality was discharge “nutrition-risk” followed by the Katz Index of ADL Score, diagnosis of congestive heart failure, discharge location (home vs. institution), age, and marital status. Within the first 4.5 years of follow-up, the relationship between “nutrition-risk” and mortality remained constant. After 4.5 years, the strength of the correlation began to diminish.

Conclusions: Among the elderly, protein-energy undernutrition present at hospital discharge appears to be a strong independent risk factor for mortality during the subsequent 4.5 years or longer.

• mortality
• geriatric
• protein-energy undernutrition

The author is grateful to Ronni Chernoff, PhD, Geriatric Research Education and Clinical Center, John L. McClellan Memorial Veterans Hospital and Department of Geriatrics, University of Arkansas for Medical Sciences, and Cindy Reid, Little Rock, Arkansas for their editorial assistance in preparing this manuscript.

Supported by a grant from the Department of Veteran’s Affairs, Health Services Research and Development Service.