Standardising and simplifying the Global Leadership Initiative on Malnutrition (GLIM) for its more general application.

Background: Malnutrition is present in 20-50% of hospital patients but its recognition is often neither timely nor complete. The Global Leadership Initiative on Malnutrition (GLIM) aims to improve this, but its successful implementation may be compromised by its dependence on (a choice of) prior screening tools and difficulties in consistent assessment of muscle mass.

Aims: To explore different approaches to screening and muscle assessment in GLIM and to offer simpler choices for its more widespread application.

Methods: (1) Data from 300 consenting in-patients provided Nutritional Risk Screening (NRS-2002), Malnutrition Universal Screening Tool (MUST), and Subjective Global Assessment (SGA) scores. GLIM scoring was preceded by NRS-2002 or MUST (using threshold scores of 1 or 2 for MUST), or no prior screening. The results of GLIM scoring preceded by different screening approaches were compared with those of SGA. (2) The literature on mid-upper arm circumference (MUAC) and calf circumference (CC) as simple, non-invasive, objective methods of muscle assessment methods was reviewed (3) The cumulative times taken to obtain GLIM scores were measured and corrected for the different screening strategies.

Results: (1) Participants' mean age was 60 years, 157 (52%) were female and mean BMI was 27.8 kg/m. In comparison with SGA, GLIM with no prior screening had the highest sensitivity (65%) and negative predictive value (NPV) (76%), but the lowest specificity (90%) and positive predictive value (PPV) (84%). The equivalent figures for GLIM with prior MUST "1" were 62%, 75%, 93% and 88%; with prior NRS-2002, 55%∗, 73%, 98%∗ and 95%∗; and with prior MUST "2", 44%∗, 69%∗, 98%∗, 95%∗. The area under an ROC curve was the highest (0.78) when GLIM was performed without screening or with prior MUST "1". (2) Being less affected by oedema and gender differences than calf circumference, MUAC could serve as a standard globally accessible muscle mass assessment method which can be supplemented by technical approaches if available and deemed necessary. (3) The overall per-capita time requirement of GLIM was 240-245 s without prior screening, and was increased by 2-3% with prior MUST "1", by 27-29% with prior NRS-2002 and decreased by 8-9% with prior MUST "2".

Conclusions: Preceding GLIM by screening can decrease its sensitivity and increase overall time utilisation; "gold standard" muscle assessment is not globally accessible. Our results therefore support considering using GLIM as a combined screening and assessment tool, with MUAC as the method of muscle assessment which can be supplemented by technical approaches if available and deemed necessary. This could potentially both simplify the use of GLIM and improve the early detection of malnutrition. ∗Indicates statistically significant difference from use of GLIM without prior screening.