Long-term association between malnutrition and all-cause mortality among older adults: A 10-years follow-up study

Abstract

Prior studies have shown an association between malnutrition and mortality. However, it is uncertain whether malnutrition assessed with the Mini Nutritional Assessment (MNA) instrument is suitable for providing long-term prognostic information regarding older adults admitted to hospital. The aim of the present study was to examine if MNA-assessed malnutrition was associated with long-term mortality in older adults admitted to hospital and for how long the association persisted. 1768 older adults (≥65 years old) admitted to a Swedish hospital were assessed with the 18-item MNA during 2008-2009 and followed-up after 10 years. All-cause mortality (ACM) was analyzed separately for the five follow-up periods 0 to ≤2 years, >2 to ≤4 years, >4 to ≤6 years, >6 to ≤8 years, and >8 to ≤10 years using Cox regression models adjusted for important demographic, nutritional, and clinical confounders. The participants were on average 78.1 years old at baseline, with 56.0% being females. At 10 years follow-up, 174 (94.1%) malnourished patients, 757 (75.9%) patients at risk of malnutrition, and 297 (50.7%) well-nourished patients had died. For all follow-up periods, malnourished patients and patients at risk of malnutrition had significantly higher risks of early death in the adjusted regression analyses when compared with well-nourished patients (all P<0.05), with the highest risk observed for malnourished patients. For patients still alive at 8 years, the risk of death during the following two years was 2.7 times higher for patients being malnourished at baseline (P=0.013) and 1.9 times higher for patients being at risk of malnutrition at baseline (P=0.001), compared with patients being well-nourished at baseline. MNA-assessed malnutrition is an important independent predictor of long-term mortality in older adults admitted to hospital and the association is consistent over 10 years of follow-up. In clinical practice, MNA may provide long-term prognostic information to rule out those at low risk of mortality and therefore in less need of further assessment and intervention, such that the resources can focus on those in actual need of nutritional support.