Understanding the Malnutrition Universal Screening Tool (MUST)
The Malnutrition Universal Screening Tool (MUST) is a five-step, evidence-based screening tool developed by the British Association for Parenteral and Enteral Nutrition (BAPEN). It is the nationally recognized standard for nutritional screening in the UK and is used by all NHS staff across hospitals, care homes, and community settings. The tool's primary purpose is to help healthcare professionals quickly and reliably identify adults who are malnourished, at risk of malnutrition, or obese. Its five distinct steps simplify a complex assessment into a clear, actionable process, ensuring patients receive appropriate nutritional support.
The Five Steps of the MUST Tool
- Calculate the Body Mass Index (BMI) Score: The first step involves calculating the patient's BMI using their current weight and height. A score is assigned based on the result. If a patient is obese (BMI > 30), this is also noted. If height and weight cannot be measured, alternative methods, such as Mid Upper Arm Circumference (MUAC), are used to estimate BMI.
- Determine the Weight Loss Score: This step assesses the percentage of unintentional weight loss over the past 3 to 6 months. Information is gathered from the patient, their carers, or from documented medical records. A higher percentage of unplanned weight loss results in a higher score.
- Assess the Acute Disease Effect Score: This step is crucial for patients with acute illnesses. A score is added if the patient has been acutely ill and has had, or is likely to have, no nutritional intake for more than five days. Acute illness can include conditions like critical illness, stroke, or gastrointestinal surgery.
- Calculate the Overall Risk Score: The scores from the first three steps are added together to determine the patient's overall risk of malnutrition.
- Develop a Care Plan Based on Guidelines: The final step involves creating a management plan based on the total risk score. The guidelines provided by MUST ensure that appropriate actions are taken, from routine monitoring for low-risk individuals to immediate referral to a dietitian for high-risk patients.
Why MUST is essential in the NHS
Malnutrition is a serious issue that adversely affects clinical outcomes, increasing the risk of complications, prolonging hospital stays, and impacting overall recovery. By providing a standardized, easy-to-use screening tool, MUST helps ensure that nutritional concerns are not overlooked. Early identification allows for timely intervention, such as implementing food fortification, offering oral nutritional supplements, or involving specialist dietetic teams. This proactive approach is not only vital for patient wellbeing but also contributes to greater cost-effectiveness within the healthcare system by reducing complications and readmissions.
Comparison of MUST Risk Categories and Actions
The actions required following a MUST assessment are directly determined by the patient's total score. The table below outlines the management guidelines for each risk category within the NHS.
| MUST Score | Risk Category | Required Actions | Re-screening Frequency |
|---|---|---|---|
| 0 | Low Risk | Routine clinical care. Record risk category. | Weekly (hospital), Monthly (care home), Annually (community) |
| 1 | Medium Risk | Document dietary intake for 3 days. Implement actions to improve intake if inadequate. Consider referral to a dietitian. | Weekly (hospital), Monthly (care home), Every 2-3 months (community) |
| ≥2 | High Risk | Refer to a dietitian or nutritional support team immediately. Implement and monitor care plan to improve intake. | Weekly (hospital) or as clinically indicated |
Implementation and limitations of MUST
While the MUST tool is highly effective and widely adopted, its implementation and interpretation require care. Training is essential to ensure staff are competent in its use. The tool relies on accurate measurements and reporting, and clinical judgment should always be used alongside the score. For example, in special circumstances like end-of-life care, the tool’s output should not override the patient's wishes. Another limitation is that the tool may underestimate malnutrition risk in overweight or obese patients, as its scoring is heavily influenced by low BMI. For these reasons, continuous training, regular audits, and awareness of the tool's limitations are vital for ensuring its effectiveness within the NHS.
Conclusion
The Malnutrition Universal Screening Tool (MUST) is a cornerstone of nutritional care within the NHS. Its systematic five-step process enables healthcare staff to efficiently screen, assess, and manage the nutritional status of adult patients in a variety of settings. By standardizing the identification of malnutrition risk, the MUST tool facilitates early intervention, improving patient outcomes, reducing hospital stays, and ensuring that those in need receive appropriate dietary support. Its widespread use, supported by clear management guidelines, demonstrates its vital role in delivering high-quality, patient-centered care. For more in-depth guidance on MUST and related nutritional care standards, the National Institute for Health and Care Excellence (NICE) website provides valuable resources.
A practical list of the 5 MUST steps
- Step 1: Calculate BMI Score: Measure height and weight to get the BMI. Assign 0 points if BMI is >20, 1 point if 18.5–20, and 2 points if <18.5.
- Step 2: Note Weight Loss Score: Record percentage of unplanned weight loss in the past 3-6 months. Score 0 for <5%, 1 for 5–10%, and 2 for >10%.
- Step 3: Establish Acute Disease Effect Score: Check for acute illness with likely or actual no nutritional intake for >5 days. Assign 2 points if yes, 0 if no.
- Step 4: Sum the Scores: Add the scores from steps 1, 2, and 3 to find the total malnutrition risk score.
- Step 5: Refer to Management Guidelines: Use the total score to follow the corresponding care plan, which may include monitoring, dietary changes, or dietitian referral.
