Malnutrition Universal Screening Tool (MUST)

What is MUST?

The Malnutrition Universal Screening Tool (MUST) is a validated, fivestep screening instrument designed to identify adults at risk of malnutrition, to prompt appropriate clinical action, and to monitor the effectiveness of interventions. Developed by the British Association for Parenteral and Enteral Nutrition (BAPEN), it is widely used in hospitals, community settings, care homes, and increasingly in primary care.

Why screening matters

Malnutrition is associated with higher rates of infection, delayed wound healing, reduced functional capacity, longer hospital stays, and increased mortality. Early identification allows healthcare professionals to:

• Implement nutrition support before clinical deterioration.
• Prioritise resources for those most at risk.
• Track outcomes and improve quality of care.

The Five Steps of MUST

1. Calculate BMI

Measure the individuals height and weight and calculate Body Mass Index (BMI). The BMI score is assigned as follows:

2. Assess Unplanned Weight Loss

Determine the percentage of weight loss over the past 36 months (or longer if the loss is recent). Scoring:

3. Acute Disease Effect

If the patient is acutely ill and there is no nutritional intake for more than 5 days, add a score of 2. This step reflects the rapid catabolic stress placed on the body.

4. Add the Scores

The total MUST score is the sum of the three components (BMI, weight loss, acute disease). Scores are interpreted as:

• 0 Low risk
• 1 Medium risk
• 2 High risk

5. Management Plan

Based on the risk category, the tool guides the next steps:

How to Use MUST in Practice

Below is a simple workflow for incorporating MUST into routine assessments:

1. Gather data: Weight, height, recent weight history, and current intake.
2. Calculate scores: Use the tables above or an online calculator.
3. Document: Record the total score, risk category, and any immediate actions taken.
4. Implement interventions: Nutrition counseling, oral nutritional supplements, or referral for enteral/parenteral feeding when indicated.
5. Monitor: Reassess according to the recommended intervals and adjust the care plan as needed.

Key Points for Different Settings

Hospital Inpatient Units

Screen within 24hours of admission and repeat at discharge or if clinical status changes.

Community and Primary Care

Screen during routine visits, especially for older adults, those with chronic disease, or postoperative patients.

Care Homes

Perform baseline screening on admission and at least annually thereafter.

Limitations and Considerations

While MUST is robust, it is not without constraints:

• Accuracy of weight data: Inaccurate or missing weights can skew results. Use calibrated scales and consider alternative measurements (e.g., midupper arm circumference) when weight cannot be obtained.
• Population specificity: The tool was developed for adults; pediatric populations require different screening methods.
• Cultural and linguistic barriers: Ensure the questionnaire is available in the patients primary language and culturally appropriate.

Resources and Further Reading

For more detailed guidance, visit the following sources:

• BAPEN MUST Official Page
• NICE Clinical Guideline on Nutrition Support
• WHO Guidelines on the Management of Malnutrition

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