Understanding the Malnutrition Universal Screening Tool (MUST)
The Malnutrition Universal Screening Tool, or MUST, is a universally recognized, five-step framework developed by the British Association for Parenteral and Enteral Nutrition (BAPEN). It is designed to be a quick, simple, and effective way to identify adults who are malnourished, at risk of malnutrition, or obese across various care settings, including hospitals, community clinics, and care homes. The tool's significance lies in its ability to standardize the approach to nutritional assessment, ensuring that at-risk patients are identified early and receive appropriate care. Early detection of malnutrition can significantly improve patient outcomes, reduce hospital stays, and decrease associated healthcare costs.
The Five-Step Process of a MUST Nutrition Screening
Performing a MUST screening involves a straightforward, methodical approach. The process culminates in a total score that places the patient into a specific risk category, guiding the subsequent course of action.
Step 1: Calculate the BMI Score
The first step requires calculating the patient's Body Mass Index (BMI). Height and weight should be measured using appropriate equipment, though alternative measurements like mid-upper arm circumference (MUAC) can be used if standard measurements are not possible.
- BMI over 20 kg/m$^2$ (over 30 for obese): Score 0.
- BMI between 18.5 and 20 kg/m$^2$: Score 1.
- BMI less than 18.5 kg/m$^2$: Score 2.
Step 2: Note the Weight Loss Score
This step assesses any unplanned weight loss over the last three to six months. Information can be gathered from the patient, a caregiver, or medical records.
- Unplanned weight loss less than 5%: Score 0.
- Unplanned weight loss between 5-10%: Score 1.
- Unplanned weight loss greater than 10%: Score 2.
Step 3: Establish the Acute Disease Effect Score
An acute disease or injury can significantly impact a patient's nutritional status. If a patient is acutely ill and has had, or is likely to have, no nutritional intake for more than five days, a score is added.
- No acute disease effect: Score 0.
- Yes, acute disease effect is present: Score 2.
Step 4: Calculate the Overall Risk Score
The scores from steps 1, 2, and 3 are combined to determine the overall risk of malnutrition. The total score indicates the patient's risk level.
Step 5: Develop and Implement Management Guidelines
Based on the overall risk score, management guidelines are established. These guidelines range from routine clinical care to urgent intervention, including referral to a dietitian or nutritional support team.
Interpreting the MUST Score and Management Guidelines
Interpreting the final score is crucial for dictating the appropriate care plan and monitoring frequency.
- Score 0 (Low Risk): Routine clinical care. Patients should be re-screened periodically, such as weekly in a hospital, monthly in a care home, or annually in the community.
- Score 1 (Medium Risk): Observation is required. Nutritional intake should be documented for three days. If intake is adequate, continue routine care with increased frequency of re-screening. If intake is inadequate, follow local policy and set goals to improve intake.
- Score 2 or more (High Risk): Treat immediately. Refer to a dietitian or nutritional support team to establish an intensive care plan. Review and monitor the care plan regularly.
How Different Healthcare Settings Utilize MUST
The versatility of the MUST tool makes it applicable and valuable across various healthcare environments. The specific application and follow-up procedures often vary based on the setting.
- Hospitals: Patients are typically screened upon admission and then re-screened weekly. This rapid, standardized assessment helps ensure that nutritional deficiencies, which can impact recovery and length of stay, are addressed from the outset.
- Care Homes: Residents are screened upon admission and then typically monthly. Given the prevalence of malnutrition among elderly populations, this routine screening is essential for maintaining residents' health and well-being.
- Community: Screening in the community, often performed during routine health checks, is recommended annually for specific risk groups, such as those over 75 years of age. For medium-risk individuals, re-screening may be conducted every 2-3 months.
Comparison of Nutritional Screening Tools
| Feature | Malnutrition Universal Screening Tool (MUST) | Mini Nutritional Assessment-Short Form (MNA-SF) | Nutritional Risk Screening 2002 (NRS-2002) |
|---|---|---|---|
| Target Population | Adults across all settings | Primarily elderly (65+) | Primarily hospital inpatients |
| Components | BMI, unplanned weight loss, acute disease effect | Appetite, weight loss, mobility, acute stress, neuropsychological issues, BMI | BMI, weight loss, severity of illness |
| Simplicity | High. Uses simple tables and scores. | Moderate. Questionnaire format. | Moderate. Involves initial screening questions. |
| Detection | Undernutrition, obesity | Undernutrition | Undernutrition |
| Developer | BAPEN (British Association for Parenteral and Enteral Nutrition) | European Society for Clinical Nutrition and Metabolism (ESPEN) |
Alternative Measurements When Standard Metrics Are Not Possible
In situations where a patient's height or weight cannot be accurately measured due to physical limitations, alternative methods can be used to estimate nutritional status for the MUST screening.
- Mid-Upper Arm Circumference (MUAC): Measuring the circumference of the mid-upper arm can provide a proxy for BMI. A MUAC less than 23.5cm suggests a BMI of less than 20 kg/m$^2$, while a MUAC greater than 32.0cm suggests a BMI over 30 kg/m$^2$.
- Subjective Clinical Impression: In some cases, a healthcare professional’s clinical judgment based on observing the patient's physical state (e.g., obvious wasting or obesity) may be used to establish a risk level when objective data is unavailable.
- Reported Weight History: If a recent weight from a reliable source is available, or if the patient can credibly report their recent weight, this information can be used to calculate weight loss percentage.
Conclusion: The Impact of Effective Nutrition Screening
Effective nutrition screening using a tool like MUST is a cornerstone of proactive patient care. It provides a structured, evidence-based method for identifying nutritional risk, which is a major factor in patient health outcomes. By moving beyond simple observation to a standardized assessment, healthcare professionals can initiate timely interventions, from basic dietary advice for medium-risk patients to specialized support from dietitians for those at high risk. This process not only addresses current health problems but also prevents the escalation of malnutrition, leading to reduced complications, faster recovery times, and improved overall quality of life for patients. The universal applicability and simplicity of the MUST screening tool make it an invaluable asset in any clinical or care setting.
For more detailed guidance and resources on the MUST tool, visit the BAPEN website.
