Malnutrition Universal Screening Tool

Abstract

The Malnutrition Universal Screening Tool (MUST) is a validated, quick, five-step screening checklist designed to identify adults who are malnourished, or at risk of malnutrition, across various care settings. The tool incorporates three primary criteria: calculation of the patient’s Body Mass Index (BMI), assessment of recent unintentional weight loss, and evaluation of the acute effects of disease on nutritional intake. Each component is scored on a two- or three-point scale, resulting in a total score that dictates the appropriate level of nutritional intervention and monitoring required for the patient. The assessment process is rapid, typically requiring less than five minutes per patient, making it highly effective for routine clinical screening.

Keywords

Malnutrition, Nutritional Screening, MUST, Nutritional Assessment, BMI, Older Adults, Food Intake, Acute Disease, Clinical Risk Assessment.

Authors

Elia M (2003), Stuurgroep ondervoeding (Malnutrition Steering Group) (Dutch version).

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Purpose

The primary purpose of the Malnutrition Universal Screening Tool (MUST) is to facilitate the systematic identification and classification of adults in clinical and community settings who are at risk of, or currently experiencing, poor nutritional status. By providing a clear, evidence-based scoring system, MUST enables healthcare professionals to determine the severity of nutritional risk—categorized as low, medium, or high—and subsequently implement timely and appropriate nutritional care plans and interventions.

This systematic approach ensures that resources are allocated efficiently, prioritizing patients with the greatest need for nutritional support. The tool is designed for ease of use by all members of the healthcare team, including nurses, dietitians, and general practitioners, thereby promoting universal application of nutritional screening protocols.

Construct

The MUST tool measures the construct of nutritional risk, which is operationalized through three key independent indicators that strongly predict adverse health outcomes associated with malnutrition. These core components address different facets of nutritional status deterioration.

• BMI Score: Assesses current body size and weight relative to height, serving as a fundamental indicator of chronic energy balance.
• Weight Loss Score: Measures the history and degree of unintentional weight loss over the preceding three to six months, reflecting recent catabolic processes or inadequate intake.
• Acute Disease Score: Evaluates the presence of an acute illness or physiological stress that has resulted in, or is likely to cause, a significant reduction in food intake for five or more days.

Validity

The MUST scale possesses strong evidence of validity, particularly in its ability to discriminate between patients who are well-nourished and those who are nutritionally compromised. Studies have established high concurrent validity when comparing MUST scores against more comprehensive and time-intensive nutritional assessments, such as Subjective Global Assessment (SGA) and detailed anthropometric measurements. This indicates that the MUST accurately reflects true nutritional status.

Furthermore, the tool demonstrates robust predictive validity. High MUST scores have been repeatedly linked to clinically significant adverse outcomes, including increased length of hospital stay, higher rates of complications, reduced quality of life, and elevated mortality rates across different adult populations, particularly among the elderly and those with chronic diseases.

Reliability

The reliability of the Malnutrition Universal Screening Tool is generally considered excellent, largely due to its objective and standardized format. The reliance on measurable data points, such as BMI calculation and defined criteria for weight loss, ensures high levels of inter-rater reliability. This means that different clinicians assessing the same patient at the same time are highly likely to derive identical or near-identical scores, minimizing subjective bias.

In settings where the patient’s nutritional status remains stable, the tool also exhibits good test-retest reliability. The clear, step-by-step guidance provided by the scoring algorithm minimizes ambiguity in interpretation, which is essential for a tool intended for universal application by staff with varying levels of nutritional expertise.

Factor Analysis

As a pragmatic, additive screening tool, the MUST does not typically undergo complex exploratory or confirmatory factor analysis in the way multi-item psychological inventories do. The structure of MUST is based on established clinical consensus regarding the core, independent risk factors for malnutrition (BMI, weight loss, acute illness). The tool sums the scores of these three conceptually distinct factors to yield a single, unified measure of overall nutritional risk. Therefore, the structure is accepted as criterion-referenced, reflecting the cumulative burden of nutritional deficits rather than latent psychological dimensions.

Instrument

Test Type: Nutritional Clinical assessment, Screening Tool, Checklist

Format: Structured observation and calculation based on patient data (BMI), interview (weight loss history), and medical record review (acute illness).

Language Available: English (Original), Dutch, and numerous other translations used globally.

Population Group: Clinical and Community settings.

Age Group: Adults, including Older Adults and Geriatrics.

Population Details: Applicable to all adult patients (over 18 years) in hospitals, long-term care facilities, and primary care settings, regardless of medical diagnosis.

Test Methodology: Five-step process involving anthropometric measurement, calculation, history taking, scoring, and determination of management category. Administration time is typically less than 5 minutes.

Keywords

Nutritional Risk, Clinical Intervention, Weight Loss, Hospital Care, BAPEN, Anthropometry, Screening Protocol, Public Health.

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Authors

Author ORCID Identifier: Not publicly specified for primary author Elia M.

Affiliation Email addresses: Information not provided in source.

Correspondence Address: Information not provided in source.

Permissions & Fee and Test Year

The Malnutrition Universal Screening Tool was originally developed by M. Elia in 2003 on behalf of the British Association for Parenteral and Enteral Nutrition (BAPEN). The tool is generally made available for free use in clinical practice, provided that its application adheres to the official guidelines and protocols established by BAPEN. The primary development year is 2003.

Reference’s

Elia M (2003). The Malnutrition Universal Screening Tool (‘MUST’) for adults: a multipurpose screening tool, developed for use in all settings. BAPEN.

Stuurgroep ondervoeding (Dutch version developers).

The original Dutch Explanation Form (Toelichtingsformulier) can be downloaded here: Toelichtingsformulier PDF.

The original Dutch Measurement Instrument (Meetinstrument) can be downloaded here: Meetinstrument PDF.

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Items of the Malnutrition Universal Screening Tool

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

The source content provided the domains of the MUST tool but did not include the specific scoring items or thresholds. The domains are:

1. BMI (Body Mass Index) Score
2. Unintentional Weight Loss Score (Voedselinname)
3. Acute Disease Effect Score (acute ziekte)