Clinical Outcomes Associated With Malnutrition Diagnosed by the Academy of Nutrition and Dietetics and American Society for Parenteral and Enteral Nutrition Indicators of Malnutrition: A Systematic Review of Content Validity and Meta-Analysis of Predictive Validity.

Background The Academy of Nutrition and Dietetics-American Society for Parenteral and Enteral Nutrition Indicators of Malnutrition (AAIM) is a tool that uses nutrition assessment parameters to diagnose patients with malnutrition. Evaluation of the content validity of AAIM relative to the Subjective Global Assessment (SGA) or Patient Generated-Subjective Global Assessment (PG-SGA) is needed. Predictive validity of malnutrition diagnosed by AAIM for clinical outcomes in hospitalized adults is also important. Objective The purpose of this systematic review of the published literature was to evaluate the content validity of the AAIM approach relative to SGA/PG-SGA and to determine whether malnutrition diagnosed by AAIM at or near hospital admission is associated with increased mortality, length of stay, hospitalization cost, or readmissions. Methods Observational studies of hospitalized adult patients published in English during 5/1/2012-6/1/2023 were identified using Pubmed, CINAHL, EMBASE or Cochrane Library. The risk of bias of outcome studies was evaluated by the National Institutes of Health quality assessment tool for observational studies. Effect sizes from three or more studies were combined into forest plots using Review Manager 5.0 to produce effect sizes expressed as odds ratios or mean differences with 95% confidence intervals (CI) using the inverse variance method with a random effects model, and computation of the I2 statistic to indicate heterogeneity. Visual examination of funnel plots was used to assess likelihood of publication bias. Results Eighteen studies with data from 14,794 patients were included. In the nine studies that provided content validation data, five did not measure hand grip strength. Nonetheless, AAIM demonstrated 89% sensitivity, 84% specificity, and substantial agreement with the SGA/PG-SGA. Sixteen studies reported clinical outcomes. Malnutrition diagnosed by AAIM was associated with greater OR (95% CI) hospital mortality of 2.37(1.58 to 3.55) and increased OR (95% CI) 30-day readmissions of 2.26 (1.97 to 2.58) than patients without malnutrition. While a specific effect size was not established due to study heterogeneity, longer length of stay was confirmed in five adjusted models. Two studies reported significantly increased costs of hospitalization in patients with malnutrition. Conclusions The AAIM criteria are valid in content relative to SGA/PG-SGA. Malnutrition diagnosed by AAIM identifies patients with greater odds of hospital mortality, and 30-day readmissions as well as longer hospital length of stay.