Malnutrition Universal Screening Tool and Patient-Generated Subjective Global Assessment Short Form and their predictive validity in hospitalized patients

Background and aims: Malnutrition screening is a first step in the nutrition care process for hospitalized patients, to identify those at risk of malnutrition and associated worse outcome, preceding further assessment and intervention. Frequently used malnutrition screening tools including the Malnutrition Universal Screening Tool (MUST) mainly screen for characteristics of malnutrition, while the Patient-Generated Subjective Global Assessment Short Form (PG-SGA SF) additionally includes risk factors for development of malnutrition, yielding a higher percentage of patients at risk. To investigate whether this translates into higher risk of worse outcome, we aimed to determine the predictive validity of MUST and PG-SGA SF for prolonged hospitalization >8 days, readmission, and mortality <6 months after hospital discharge.Methods: In this observational study, MUST was performed according to university hospital protocol. Additional screening using PG-SGA SF was performed within 24 h of hospital admission (high risk: MUST ≥ 2, PG_SGA SF ≥ 9). Associations of MUST and PG-SGA SF with outcomes were analyzed by logistic- and Cox PH-regression.Results: Of 430 patients analyzed (age 58 ± 16 years, 53% male, BMI 26.9 ± 5.5 kg/m2), MUST and PG-SGA SF identified 32 and 80 at high risk, respectively. One-hundred-eight patients had prolonged hospitalization, 109 were readmitted and 20 died. High risk by MUST was associated with mortality (HR = 3.9; 95% CI 1.3–12.2, P = 0.02), but not with other endpoints. High risk by PG-SGA SF was associated with prolonged hospitalization (OR = 2.5; 95% CI 1.3–5.0, P = 0.009), readmission (HR = 1.9; 95% CI 1.1–3.2, P = 0.03), and mortality (HR = 34.8; 95% CI 4.2–289.3, P = 0.001), independent of age, sex, hospital ward and previous hospitalization <6 months. In the 363/430 patients classified as low risk by MUST, high risk by PG-SGA SF was independently associated with higher risk of readmission (HR = 1.9; 95% CI 1.0–3.5, P = 0.04) and mortality (HR = 19.5; 95% CI 2.0–189.4, P = 0.01).Conclusions: Whereas high malnutrition risk by MUST was only associated with mortality, PG-SGA SF was associated with higher risk of prolonged hospitalization, readmission, and mortality. In patients considered as low risk by MUST, high malnutrition risk by PG-SGA SF was also predictive of worse outcome. Our findings support the use of PG-SGA SF in routine care to identify patients at risk of malnutrition and worse outcome, and enable proactive interventions.