What is the MUST Calculation Tool?
The Malnutrition Universal Screening Tool (MUST) is a validated, five-step screening tool designed for healthcare professionals to identify adults at risk of malnutrition (undernutrition) or obesity. Developed by BAPEN, it is used in various settings, including hospitals, community clinics, and care homes, to ensure consistent nutritional assessment and timely intervention.
The Five Steps of the MUST Calculation
The MUST calculation involves five steps to assess a patient's nutritional status.
Step 1: Body Mass Index (BMI) Score
Step 1 involves calculating BMI from height and weight, with scores assigned based on categories including > 20, 18.5–20, and < 18.5 kg/m². Alternative methods can be used if measurements are not possible.
Step 2: Unplanned Weight Loss Score
Step 2 assesses unplanned weight loss over 3 to 6 months, scoring based on percentages < 5%, 5–10%, or > 10%. Patient records or self-report can be used.
Step 3: Acute Disease Effect Score
Step 3 scores the impact of acute illness on nutritional intake. A score of 2 indicates high risk if acute illness causes no nutritional intake for > 5 days.
Step 4: Overall Risk of Malnutrition
Step 4 sums the scores from Steps 1-3 to categorize risk as Low (0), Medium (1), or High (≥ 2).
Step 5: Management Guidelines
Step 5 involves developing a care plan based on the risk category: Low Risk needs routine care, Medium Risk requires dietary observation, and High Risk necessitates nutritional treatment and referral.
Comparison of MUST and Other Screening Tools
The table below compares key features of the MUST and NRS-2002 tools. {Link: clinicalnutrition.science https://clinicalnutrition.science/en/nutriscreen/}
| Feature | Malnutrition Universal Screening Tool (MUST) | Nutritional Risk Screening (NRS-2002) |
|---|---|---|
| Target Population | Adults in all care settings | Hospitalized adults |
| Key Parameters | BMI, unintentional weight loss, acute disease effect | BMI, recent weight loss, recent food intake, severity of illness, age >70 years |
| Number of Steps | 5 steps | 4-step initial screening + 4-step assessment if risk indicated |
| Focus | Identification of malnutrition, undernutrition, and obesity risk | Detection and quantification of undernutrition risk in hospitals |
| Primary Use | Universal screening, easy to implement | Guiding nutritional support decisions in hospital settings |
Benefits and Limitations of the MUST Tool
Benefits
- Versatility: Applicable across various care settings.
- Simplicity and Speed: Straightforward five-step process.
- Evidence-Based: Validated and nationally recognized.
- Early Intervention: Facilitates timely detection and intervention.
Limitations
- Not a Diagnostic Tool: Screening only, high score needs further assessment.
- Limited Scope: Does not detect specific vitamin or mineral deficiencies.
- Poor Frailty Detection: Low sensitivity for identifying frailty.
- Not for All Populations: Designed for adults; not suitable for children or pregnant/lactating women without consideration.
How to Train Staff in Using the MUST Tool
Effective training is crucial for accurate and consistent MUST implementation. Training should cover theoretical understanding, practical application (including alternative measurements), scenario-based learning, care plan development, and documentation.
Conclusion
The MUST calculation tool is a vital, standardized five-step screening method for identifying adults at risk of malnutrition. By assessing BMI, unplanned weight loss, and the impact of acute illness, it provides a reliable risk score to guide clinical management. Despite limitations, its widespread applicability and ease of use make it essential for healthcare professionals to provide timely nutritional support. For further details and resources, visit the BAPEN website(https://www.bapen.org.uk/).
