Malnutrition is a common and often unrecognized condition that significantly impacts patient recovery and overall health outcomes. Data suggests that nearly 30% of patients admitted to hospitals in the United Kingdom may be at risk, highlighting the widespread nature of the problem. The effects of poor nutrition are far-reaching, contributing to weakened immune systems, slower wound healing, and longer hospital stays. Identifying individuals at risk early through a standardized approach is an important step toward implementing effective nutritional support. The complexity of assessing nutritional status across diverse healthcare settings necessitates a simple, validated, and universally applicable screening tool.
Defining the Malnutrition Universal Screening Tool
The need for a quick and consistent method led to the development of the Malnutrition Universal Screening Tool, commonly known as ‘MUST’. This five-step process was created by the Malnutrition Advisory Group, which operates as a standing committee of the British Association for Parenteral and Enteral Nutrition (BAPEN). The fundamental goal of MUST is to accurately identify adults who are already malnourished, are at risk of undernutrition, or who are obese.
MUST is designed to be rapid, non-invasive, and suitable for use by all care workers, not just specialist dietitians. Its structure promotes ease of use and reproducibility, which helps in standardizing nutritional care across different environments. The tool has been regularly reviewed since its launch in 2003 and provides a consistent framework for initial assessment.
Calculating the Screening Score
The core of the MUST process involves following five distinct steps to calculate a final score that corresponds to a level of nutritional risk. The first three steps involve assigning numerical scores based on specific clinical parameters, which are then summed to determine the overall risk category.
Step 1: Body Mass Index (BMI)
The first parameter assessed is the Body Mass Index (BMI), calculated from the individual’s height and current weight. A BMI greater than 20 kg/m² results in a score of 0 points. A BMI between 18.5 and 20 kg/m² is assigned 1 point. Individuals with a BMI below 18.5 kg/m² receive the highest score of 2 points, indicating a greater baseline risk.
Step 2: Unintentional Weight Loss
The second step assesses recent unintentional weight loss over the past three to six months. If the patient has lost less than 5% of their body weight, they receive 0 points. A loss between 5% and 10% is assigned 1 point, and a weight loss exceeding 10% warrants a score of 2 points.
Step 3: Acute Disease Effect
The third component evaluates the effect of acute disease on nutritional intake. This step assigns a score of 2 points if the patient is acutely ill and has had little or no nutritional intake for five or more consecutive days. This factor recognizes that inability to feed due to illness can rapidly escalate the risk of malnutrition. This scoring step is primarily relevant in hospital or acute care settings.
Step 4 & 5: Total Score and Risk Category
The fourth step requires adding the three individual scores (BMI, weight loss, and acute disease effect) to obtain the total MUST score. The final step uses this sum to establish the overall risk category for malnutrition. A total score of 0 indicates Low Risk, a score of 1 indicates Medium Risk, and any score of 2 or more places the individual in the High Risk category.
Developing a Care Plan Based on Risk
The overall risk category determined by the MUST score directly dictates the specific management guidelines and intervention strategies.
Low Risk (Score 0)
Individuals assessed as Low Risk require routine clinical care. This group still requires re-screening, with the frequency varying by setting. The primary focus for this low-risk group is to maintain their current nutritional status and prevent future decline.
Medium Risk (Score 1)
Patients in the Medium Risk category require a more active level of observation and assessment. The initial step is to formally observe and document the patient’s dietary intake over a three-day period, particularly in hospital or care home environments. If this observation reveals adequate intake, the care plan may focus on continued monitoring and re-screening. If the intake is inadequate or there is clinical concern, a localized care plan must be implemented to improve nutritional consumption.
High Risk (Score 2 or More)
The High Risk category demands immediate and comprehensive intervention to treat the malnutrition. This typically involves an immediate referral to a specialist, such as a dietitian or a dedicated Nutritional Support Team, for a detailed assessment and individualized care plan. Actions include setting clear nutritional goals and implementing strategies like providing high-protein, high-calorie fortified foods and drinks. The care plan for high-risk patients requires frequent monitoring and review.
For all risk levels, a foundational step involves treating any underlying medical conditions that contribute to the nutritional decline and providing advice on food choices. Re-screening frequency varies significantly depending on the environment:
- In hospital settings, re-screening should occur weekly.
- In care home settings, re-screening should occur at least monthly.
- In community settings, re-screening should occur every two to three months for medium risk patients.
- In community settings, re-screening should occur annually for low risk patients.
Widespread Application and Context
The Malnutrition Universal Screening Tool is widely utilized across various healthcare environments due to its adaptability and simplicity. It is successfully applied in diverse settings, including acute care hospitals, long-term care facilities like nursing homes, and primary care or community services. This universality allows for a seamless transition of care and consistent nutritional assessment regardless of where the patient is being treated. Its widespread adoption makes it the most commonly used nutritional screening tool within the UK and many other countries.
The tool’s role in standardizing care is supported by major clinical guidance bodies. Guidelines from the National Institute for Health and Care Excellence (NICE) recommend that a validated screening tool be used to assess Body Mass Index and unintentional weight loss, citing BAPEN’s MUST as a suitable example. This endorsement highlights its evidence-based foundation and effectiveness in supporting accuracy and consistency across different health and social care providers.