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Malnutrition in Hospitalized Adults

Systematic Review

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Main Points

  • Association Between Malnutrition and Clinical Outcomes
    • Patients requiring intensive care unit (ICU) care and diagnosed with malnutrition (using Subjective Global Assessment [SGA]) may have higher hospital mortality compared to well-nourished patients requiring ICU care.
    • Patients requiring ICU care and diagnosed with malnutrition (using SGA) are likely to experience prolonged hospital length of stay compared to well-nourished patients requiring ICU care.
    • Patients requiring ICU care and diagnosed with malnutrition (using Mini Nutritional Assessment [MNA]) may experience more hospital acquired complications compared to well-nourished patients requiring ICU care.
    • Patients hospitalized due to traumatic injury and screened at risk of malnutrition (using Nutritional Risk Screening [NRS]-2002) may experience more hospital acquired conditions compared to well-nourished patients.
    • Patients hospitalized with heart failure and diagnosed with malnutrition (using several different measurement tools) may have higher mortality compared to well-nourished patients with heart failure.
    • Patients hospitalized with cancer and diagnosed with malnutrition (using SGA) may experience prolonged hospital length of stay compared to well-nourished patients.
    • Patients hospitalized with cirrhosis awaiting transplantation and diagnosed with malnutrition (using SGA) may have higher pre-transplant mortality compared to well-nourished patients.
  • Effectiveness of Screening on Clinical Outcomes
    • No studies met inclusion criteria to address effectiveness of screening or diagnostic assessment on clinical outcomes, primarily because studies lacked an appropriate control group.
    • This evidence gap underscores the need for future research that addresses the effectiveness of various measurement tools for malnutrition on clinical outcomes. Such research is vital to standardize malnutrition assessment and further understand its downstream implications on patient-relevant outcomes.
  • Effectiveness of Hospital-Initiated Interventions for Malnutrition
    • Hospital-initiated malnutrition interventions (i.e., specialized nutrition care, protein/calorie supplementation) likely decrease mortality compared to usual care.
    • Hospital-initiated malnutrition interventions may improve quality of life compared to usual care.
    • No difference was observed between hospital-initiated malnutrition interventions and usual care for length of stay, readmission rates, and hospital acquired conditions compared to usual care.
    • Evidence was insufficient to address the effect of hospital-initiated malnutrition interventions on activities of daily living and discharge disposition compared to usual care.

Structured Abstract

Objectives. To review the association between malnutrition and clinical outcomes among hospitalized patients, evaluate effectiveness of measurement tools for malnutrition on clinical outcomes, and assess effectiveness of hospital-initiated interventions for patients diagnosed with malnutrition.

Data sources. We searched electronic databases (Embase®, MEDLINE®, PubMed®, and the Cochrane Library) from January 1, 2000, to June 3, 2021. We hand-searched reference lists of relevant studies and searched for unpublished studies in ClinicalTrials.gov.

Review methods. Using predefined criteria and dual review, we selected (1) existing systematic reviews (SRs) to assess the association between malnutrition and clinical outcomes, (2) randomized and non-randomized studies to evaluate the effectiveness of malnutrition tools on clinical outcomes, and (3) randomized controlled trials (RCTs) to assess effectiveness of hospital-initiated treatments for malnutrition. Clinical outcomes of interest included mortality, length of stay, 30-day readmission, quality of life, functional status, activities of daily living, hospital acquired conditions, wound healing, and discharge disposition. When appropriate, we conducted meta-analysis to quantitatively summarize study findings; otherwise, data were narratively synthesized. When available, we used pooled estimates from existing SRs to determine the association between malnutrition and clinical outcomes, and assessed the strength of evidence.

Results. Six existing SRs (including 43 unique studies) provided evidence on the association between malnutrition and clinical outcomes. Low to moderate strength of evidence (SOE) showed an association between malnutrition and increased hospital mortality and prolonged hospital length of stay. This association was observed across patients hospitalized for an acute medical event requiring intensive care unit care, heart failure, and cirrhosis. Literature searches found no studies that met inclusion criteria and assessed effectiveness of measurement tools. The primary reason studies did not meet inclusion criteria is because they lacked an appropriate control group. Moderate SOE from 11 RCTs found that hospital-initiated malnutrition interventions likely reduce mortality compared with usual care among hospitalized patients diagnosed with malnutrition. Low SOE indicated that hospital-initiated malnutrition interventions may also improve quality of life compared to usual care.

Conclusions. Evidence shows an association between malnutrition and increased mortality and prolonged length of hospital stay among hospitalized patients identified as malnourished. However, the strength of this association varied depending on patient population and tool used to identify malnutrition. Evidence indicates malnutrition-focused hospital-initiated interventions likely reduce mortality and may improve quality of life compared to usual care among patients diagnosed with malnutrition. Research is needed to assess the clinical utility of measurement tools for malnutrition.

Citation

Uhl S, Siddique SM, McKeever L, Bloschichak A, D’Anci K, Leas B, Mull NK, Tsou AY. Malnutrition in Hospitalized Adults: A Systematic Review. Comparative Effectiveness Review No. 249. (Prepared by the ECRI–Penn Medicine Evidence-based Practice Center under Contract No. 75Q80120D00002.) AHRQ Publication No. 21(22)-EHC035. Rockville, MD: Agency for Healthcare Research and Quality; October 2021. DOI: 10.23970/AHRQEPCCER249. Posted final reports are located on the Effective Health Care Program search page.