Overall mortality for community-dwelling adults over 50 years at risk of malnutrition

It is well reported that malnutrition in acute care is associated with poorer health outcomes including increased mortality. However, the consequences of malnutrition on survival in community settings is uncertain. Malnutrition in people 65 years or over is often cited. Nevertheless, this study includes both middle-aged and older adults as current public health policy is highlighting the need to increase disease-free life years and is moving away from just extending life to increase overall longevity. The aim of this study is to describe the association of the risk of malnutrition using the Malnutrition Universal Screening Tool (MUST) with mortality in community-dwelling middle-aged and older adults.

We used the UK Biobank to investigate the association between those at risk of malnutrition and mortality in participants aged ≥50 years. MUST identified risk of malnutrition and linked data to national death registries confirmed mortality. Years of life lost (YLL) and Cox proportional hazard models with hazard ratios (HR) and confidence intervals (CI) described risk associated with all-cause mortality.

There were 502 408 participants recruited, 117 830 were ≤50 years leaving 384 578 eligible participants. Based on MUST scores 63 495 (16.5%) were at risk of malnutrition with 401 missing some data and excluded. Incidence of mortality for at risk participants was 755 per 100 000 person-years, corresponding to 153 476 YLL. Of those at risk of malnutrition, 9.5% died versus 7.8% at low risk. Initial survival analysis reported an increased risk of mortality (HR 1.29, 95% CI: 1.25 to 1.33) that decreased after adjusting for confounders (HR 1.14, 95% CI: 1.11 to 1.18) in those at risk of malnutrition versus those at low risk.

Risk of malnutrition was associated with increased overall mortality. Modest effect sizes are demonstrated but are supportive of public health policies, which advocate wide-scale community, based nutritional screening for middle-aged and older adults.