BMI-reliant screening tool underestimates malnutrition risk

The Patient-Generated Subjective Global Assessment Short Form (PG-SGA SF) seems to be a better screening tool for malnutrition risk than the body mass index (BMI)-reliant Malnutrition Universal Screening Tool (MUST), a recent study has found.

A total of 430 adult patients (mean age 58.4±16.2 years, 53.0 percent male) participated in the study and were enrolled at hospital admission. Increased malnutrition risk was defined as MUST score ≥1 or PG-SGA SF score ≥4. Thirty-five percent (n=150) of participants were overweight, while 25 percent (n=108) were deemed obese.

According to MUST, 16 percent of the total study sample were at increased risk of malnutrition, a trend that differed significantly according to BMI group (p<0.001). In particular, all patients (100 percent) in the low BMI category (<18.5 kg/m²) were at risk; in contrast, such risk was much lower in the overweight (5 percent) and obese (6 percent) groups.

Malnutrition risk was much more common when assessed by PG-SGA SF, which found that 42 percent of participants were at risk. Prevalence of such risk likewise differed significantly according to BMI (p=0.001), peaking at 91 percent in the low-BMI group and dropping to 31 percent and 42 percent in overweight and obese participants.

“Increased malnutrition risk is prevalent on hospital admission across the BMI scale, including more than one-third of patients in the overweight or obese range. Among the latter, only a small minority is identified by the currently used MUST,” the researchers said.

“Alternative tools, less dependent on BMI, such as the PG-SGA SF, should be considered for initial malnutrition screening, and additional nutrition assessment is recommended, to prevent malnutrition from being undetected and untreated in all patients, regardless of their BMI,” they added.