The MUST calculator, standing for the Malnutrition Universal Screening Tool, is a vital instrument for healthcare professionals. Its purpose is to efficiently and effectively screen adults to identify those who are malnourished, at risk of malnutrition, or obese. This process involves a systematic five-step procedure that combines several key nutritional indicators into a single, conclusive risk score. The subsequent steps guide clinical teams in developing appropriate care plans and interventions.
The Five Steps of the MUST Calculator
Step 1: Calculating the Body Mass Index (BMI) Score
The first step requires calculating the patient's BMI using their current weight and height. A BMI chart is then used to assign a corresponding score:
- A BMI of >20 kg/m² (>30 for obese) receives a score of 0.
- A BMI between 18.5 and 20 kg/m² scores 1.
- A BMI of <18.5 kg/m² receives a score of 2. In cases where objective measurements are not possible, subjective criteria based on clinical impression can be used to estimate a BMI category.
Step 2: Assessing Unplanned Weight Loss
This step evaluates the patient's unplanned weight loss over the past 3 to 6 months. This information may be obtained from patient records or, if necessary, from the patient themselves. The percentage of weight loss determines the score:
- Weight loss of <5% scores 0.
- Weight loss between 5% and 10% scores 1.
- Weight loss of >10% scores 2. Healthcare providers may also use physical signs, like loose-fitting clothing or jewellery, as an indicator.
Step 3: Scoring for Acute Disease Effect
This step checks for the impact of acute illness on nutritional intake. A score of 2 is given if the patient is acutely ill and has had, or is likely to have, little to no nutritional intake for more than five consecutive days. This is particularly relevant for critically ill patients or those with swallowing difficulties.
Step 4: Determining the Overall Risk Score
All the scores from the previous three steps are added together to produce an overall MUST score. The final score places the patient into one of three risk categories:
- Low Risk (Score 0): The patient is not malnourished and no immediate action is needed, although routine monitoring should continue.
- Medium Risk (Score 1): The patient is at risk of malnutrition. Their dietary intake should be monitored and a care plan established.
- High Risk (Score 2 or more): The patient is at high risk of malnutrition and requires immediate intervention. This typically includes a referral to a dietitian.
Step 5: Developing a Management Plan
Based on the overall risk category, a management plan is developed and implemented according to local policy. This can range from providing dietary advice and fortified food for medium-risk patients to a comprehensive nutritional support program for those at high risk.
Objective vs. Subjective Assessment
| Assessment Method | Details | Use Case | Accuracy | Scoring | Limitations |
|---|---|---|---|---|---|
| Objective Measurements | Uses standard physical measurements like height and weight. BMI is calculated directly. | Recommended whenever possible, using clinical scales and stadiometers. | High, based on specific data points. | Generates a specific numerical score. | Not always feasible for immobile patients or those with amputations. |
| Subjective Criteria | Based on clinical impression, observation of physical wasting, and patient history. | Used when objective measurements are unreliable or impossible to obtain. | Reliant on assessor's judgement, provides an estimate. | Establishes a risk category (e.g., low, medium, high), not a specific score. | Can be less precise than objective data. |
The Role and Importance of a MUST Calculator
The implementation of a MUST calculator ensures that nutritional screening is standardized and systematically carried out, which leads to more consistent care. It is a proactive tool designed to prevent the adverse health effects associated with malnutrition, such as impaired wound healing, reduced immunity, and increased hospital stays. The tool's flexibility, allowing for subjective assessment when objective data is unavailable, makes it widely applicable across a range of clinical settings. By providing clear management guidelines, it promotes a multidisciplinary approach to nutritional care involving doctors, nurses, and dietitians. Further details on its application and resources can be found on the BAPEN website.
Conclusion
In summary, a MUST calculator is a systematic, five-step assessment tool that determines an adult's risk of malnutrition or obesity by evaluating their BMI, recent weight loss, and the impact of acute illness. This powerful, validated screening instrument facilitates early identification of nutritional risk, enabling healthcare professionals to implement targeted interventions. The process culminates in a specific care plan tailored to the patient's individual needs, ultimately improving health outcomes and quality of life in both hospital and community settings.
