The Malnutrition Universal Screening Tool (MUST)
Developed by the British Association for Parenteral and Enteral Nutrition (BAPEN), the Malnutrition Universal Screening Tool (MUST) is a five-step process designed to identify adults who are malnourished or at risk of malnutrition. The tool is straightforward and effective, making it suitable for use across hospitals, care homes, and community settings by various healthcare professionals. It uses three primary criteria to calculate a score: Body Mass Index (BMI), recent unplanned weight loss, and the effect of an acute disease.
The calculation of a patient's MUST score is a systematic process:
- BMI Score: Assign a score based on the patient's Body Mass Index ($kg/m^2$). A BMI of >20 (>30 for obese) scores 0, a BMI of 18.5–20 scores 1, and a BMI of <18.5 scores 2. If BMI cannot be calculated, alternative methods like mid-upper arm circumference (MUAC) or subjective criteria can be used to estimate the risk.
- Weight Loss Score: Assess unplanned weight loss over the past 3 to 6 months. A weight loss of <5% scores 0, 5–10% scores 1, and >10% scores 2.
- Acute Disease Effect Score: Check for an acute illness where there has been, or is likely to be, no nutritional intake for more than five days. A 'yes' adds a score of 2, while a 'no' adds 0.
- Add Scores: The scores from the three steps are added together to provide an overall MUST score, which can range from 0 to 6.
- Determine Risk Category: The total score is used to determine the patient's malnutrition risk category: low, medium, or high.
Detailing What are three levels of risk in MUST?
Once the overall MUST score is calculated, healthcare providers can interpret the results to place the individual into one of three risk categories, each with its own set of management guidelines.
Low Risk (Score = 0)
An individual with a MUST score of 0 is at a low risk of malnutrition. This does not mean that no nutritional care is needed, but rather that a more aggressive approach is not immediately necessary. The standard management for this group includes routine clinical care and continued screening at regular intervals, which vary by setting (e.g., annually for at-risk groups in the community, monthly in care homes, and weekly in hospitals). It is also important to record the patient's risk category and treat any underlying medical conditions.
Medium Risk (Score = 1)
A MUST score of 1 indicates a medium risk of malnutrition. For these individuals, a period of observation is recommended to confirm nutritional status. This typically involves documenting dietary intake over a three-day period. If dietary intake is found to be adequate, the patient can return to routine clinical care with repeat screening. However, if intake is inadequate or there are other nutritional concerns, a more proactive plan, often following a 'Food First' approach, is initiated. This involves enriching meals with higher calorie and protein options and providing nourishing drinks and snacks between meals.
High Risk (Score ≥ 2)
An overall MUST score of 2 or more places an individual in the high-risk category for malnutrition. This score requires immediate and active intervention. Management for high-risk patients involves commencing nutrition therapy and often requires a referral to a dietitian or nutritional support team for a comprehensive nutritional assessment and a detailed care plan. This plan will include strategies such as providing high-calorie, high-protein fortified diets, nourishing drinks, and snacks. Nutritional therapy is regularly reviewed to monitor progress and adjust the diet as needed.
Management Strategies for Different MUST Risk Levels
The transition from risk identification to practical dietary management is crucial for improving patient outcomes. The table below compares the management guidelines associated with each risk level based on the MUST score.
| Feature | Low Risk (Score 0) | Medium Risk (Score 1) | High Risk (Score ≥ 2) |
|---|---|---|---|
| Action | Routine clinical care. | Observe and document dietary intake for 3 days. | Treat. Commence nutrition therapy. |
| Dietary Intervention | Treat underlying conditions; record dietary details. | Provide 'Food First' dietary advice, offering high-calorie/protein foods, nourishing drinks, and snacks if intake is poor. | Active nutrition therapy, often including oral nutritional supplements and fortified food. |
| Referral | No automatic referral needed. | Refer to dietitian or nutritional team if intake is inadequate during observation. | Refer to a dietitian or nutritional support team (NST) for assessment and care plan. |
| Review Frequency | Re-screen regularly (e.g., weekly in hospital, monthly in care homes). | Re-screen monthly or more often if clinically indicated. | Monitor and review nutrition care plan regularly, often weekly in hospital. |
The Broader Context of Nutrition
While the MUST focuses on protein-energy status, it is part of a larger nutritional picture. Proper nutrition is critical for protecting against various noncommunicable diseases, including diabetes, heart disease, and some cancers. Malnutrition itself can refer to both undernutrition (deficiency) and overnutrition (excess), both of which can have adverse effects on health. Tools like MUST help healthcare professionals to accurately screen and intervene for undernutrition, which often goes undetected despite its high prevalence. By identifying at-risk individuals, it enables tailored nutrition diets that address specific deficiencies and promote recovery and well-being. Proper nutritional care can prevent deterioration of physical function, reduce complications, and shorten convalescence.
Conclusion
The Malnutrition Universal Screening Tool is a vital component of nutritional care, providing a systematic approach to identifying and managing malnutrition risk. The clarity provided by the three risk levels—low, medium, and high—allows healthcare professionals to implement targeted and appropriate dietary interventions. From routine monitoring for low-risk individuals to intensive nutritional therapy for high-risk patients, the MUST guides the development of effective nutrition diets to improve patient outcomes and overall health. Regular screening and diligent follow-up based on these risk levels are key to combating malnutrition in various care settings.
