What is 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 widely-used, five-step method for identifying adults who are malnourished, at risk of malnutrition, or obese. Its straightforward, systematic approach ensures that nutritional risks are not overlooked, a common issue despite the high prevalence and adverse effects of malnutrition.
The Five Steps of the MUST Assessment
The MUST tool simplifies the assessment of nutritional status by breaking it down into a clear, five-step process that can be performed by any trained healthcare professional:
- BMI Score: The individual's Body Mass Index (BMI) is calculated from their height and weight. If measurements are unavailable, alternative procedures like using ulna length or reported figures can be used. A low BMI is a primary indicator of malnutrition risk.
- Unplanned Weight Loss Score: The percentage of unintentional weight loss over the past 3-6 months is assessed and scored. Significant, unexplained weight loss is a critical indicator of deteriorating nutritional health.
- Acute Disease Effect Score: A score is added if the patient has an acute illness and has had, or is likely to have, no nutritional intake for more than five days. This acknowledges that disease-related inflammation and hypermetabolism can quickly exacerbate nutritional decline.
- Overall Risk Score: The scores from the first three steps are added together to determine the overall risk category: low risk (score 0), medium risk (score 1), or high risk (score 2 or more).
- Management Guidelines: Based on the risk category, appropriate management guidelines are followed to create a tailored care plan. This includes monitoring for low-risk individuals, observing dietary intake for medium-risk patients, and immediate referral to a dietitian for those at high risk.
Why is Universal Screening So Important?
Universal nutritional screening using a standardized tool like MUST is a cornerstone of effective nutritional care. It addresses the issue of undetected malnutrition, which often arises due to a lack of awareness and standardized protocols.
Improved Patient Outcomes
Early detection of malnutrition or risk factors allows for prompt intervention, which directly impacts patient recovery and well-being. The benefits include:
- Reduced Complication Rates: Malnourished patients are more susceptible to infections, pressure ulcers, and other post-operative complications. Timely nutritional support reduces these risks.
- Shorter Hospital Stays: Studies have shown that addressing malnutrition can lead to better recovery rates and shorter lengths of hospital stay.
- Better Recovery and Quality of Life: Proper nutrition is essential for the body's healing processes. Early intervention helps replenish depleted stores, supporting faster recovery and improving overall quality of life. A study in cardiovascular surgery patients found that MUST was the most effective tool for predicting postoperative decline in activities of daily living.
Financial Benefits and Cost-Effectiveness
From a healthcare system perspective, the financial implications of managing malnutrition are significant. Universal screening is a highly cost-effective strategy:
- Lower Overall Costs: By preventing prolonged hospital stays and managing complications, nutritional intervention following screening can lead to substantial reductions in healthcare costs.
- Efficient Resource Allocation: Standardized screening allows resources, such as specialist dietitians, to be targeted towards the patients who need them most, rather than being used for universal assessment. It acts as a triage tool for nutritional support.
Comparison: MUST vs. Other Screening Tools
While several nutritional screening tools exist, MUST is distinguished by its practical application and versatility across different care settings. The following table compares MUST with other common tools.
| Feature | Malnutrition Universal Screening Tool (MUST) | Nutritional Risk Screening 2002 (NRS-2002) | Mini Nutritional Assessment - Short Form (MNA-SF) |
|---|---|---|---|
| Target Population | General adult population across all care settings | Hospitalized patients | Specifically validated for geriatric patients |
| Core Components | BMI, recent unplanned weight loss, acute disease effect | BMI, weight loss, severity of disease, reduced food intake | Food intake, weight loss, mobility, psychological stress, neuropsychological problems |
| Ease of Use | Quick and simple, requiring minimal training | More complex, often requires more training | User-friendly for elderly patients, can use calf circumference if BMI is unavailable |
| Key Strength | Universal applicability and simplicity | Strong correlation with clinical outcomes in hospitalized patients | High sensitivity in its target population |
| Limitations | May not identify malnutrition risk in patients without significant BMI or weight changes | May have lower specificity in some populations compared to MUST | Poor sensitivity in general hospital populations |
Implementing MUST in Practice
Successful implementation of MUST involves a systematic approach and consistent rescreening.
- Hospitals: Patients should be screened upon admission and at least weekly thereafter. This ensures that any acute changes in nutritional status are captured.
- Care Homes: Residents should be screened upon entry and re-screened on a monthly basis, or whenever a clinical concern arises.
- Community: Screening should be opportunistic and conducted periodically, for example, during routine health checks. Low-risk patients can be rescreened annually.
The process requires standardized documentation of the risk category and subsequent care plans. For those at medium risk, dietary intake should be monitored for three days, with action taken if intake is inadequate. High-risk patients require immediate dietary assessment and intervention.
Conclusion
The Malnutrition Universal Screening Tool (MUST) is more than just a procedural checklist; it is a critical instrument for proactive patient care. By systematically and consistently identifying individuals at risk of malnutrition, healthcare providers can initiate early and effective nutritional interventions. This simple but powerful process is fundamental to improving clinical outcomes, enhancing patient recovery, reducing healthcare complications, and controlling costs across all care settings. The universal application of MUST empowers healthcare professionals to provide diligent, compassionate, and effective nutritional support, reinforcing the vital link between good nutrition and good health.
Keypoints
- Early Detection: The Malnutrition Universal Screening Tool (MUST) identifies adults at risk of malnutrition through a systematic five-step process.
- Simplified Assessment: MUST scores are derived from BMI, recent unplanned weight loss, and the effect of acute disease, making it simple to use.
- Improved Outcomes: Universal screening leads to early intervention, reducing complications, shortening hospital stays, and enhancing patient recovery.
- Cost-Effective Care: Proactive identification and management of malnutrition significantly lower overall healthcare costs by preventing costly complications.
- Versatile Application: The tool is validated for use across various settings, including hospitals, care homes, and community-based care.
- Clear Management Guidelines: MUST provides clear, risk-based management strategies, from monitoring for low-risk individuals to immediate dietary intervention for high-risk patients.
Faqs
What are the five steps of the MUST tool? The five steps are: calculating the BMI score, noting the unplanned weight loss score, adding a score for acute disease effect, combining these scores to get the overall risk, and following management guidelines based on the risk category.
Who is the MUST tool intended for? The MUST tool is designed for use with the general adult population, including those in hospitals, care homes, and the community. It is not designed for children.
What is considered a high-risk score on the MUST tool? A score of 2 or more, based on the combined scores of BMI, weight loss, and acute disease effect, indicates a high risk of malnutrition.
Can MUST be used for patients who cannot be weighed? Yes, the tool includes alternative procedures for assessing nutritional risk, such as using estimated height from ulna length or relying on subjective criteria.
How often should a patient be screened with the MUST tool? Screening frequency depends on the setting and risk level. High-risk patients require immediate intervention. Low-risk patients should be rescreened annually in the community, monthly in care homes, and weekly in hospitals.
What happens if a patient scores as medium risk? For a medium-risk score, a patient's dietary intake should be monitored for three days. If intake is adequate and there are no other concerns, they revert to routine care, but if intake is poor, further action is needed.
Does MUST replace a full nutritional assessment by a dietitian? No, MUST is a screening tool, not a diagnostic one. It serves as a triage to identify those who need a full nutritional assessment and intervention by a qualified dietitian.
Is MUST suitable for patients receiving end-of-life care? It is important to note that MUST is not suitable for patients receiving end-of-life care, where nutritional goals may differ.
Citations
Malnutrition Universal Screening Tool "MUST" - Apex Experts. (2024, March 15). Apex Experts. https://www.apexexperts.co.uk/post/malnutrition-universal-screening-tool Malnutrition Universal Screening Tool (MUST) - Geeky Medics. (2025, January 23). Geeky Medics. https://geekymedics.com/malnutrition-universal-screening-tool-must-osce-guide/ Nutritional Assessment - StatPearls - NCBI Bookshelf. (2023, April 10). National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/books/NBK580496/ How to calculate MUST scores - Log my Care. Log my Care. https://www.logmycare.co.uk/blog/how-to-calculate-must-scores Comparison of nutritional screening tools to assess nutritional ... (2020, March 26). BMC Gastroenterology. https://bmcgastroenterol.biomedcentral.com/articles/10.1186/s12876-020-01214-1
