Free tool for APDs
Which screening tool fits which setting, what each one actually measures, and what to do with a positive result. Includes a live MST calculator. Screening only, not a diagnosis.
Screening only, not diagnostic or clinical advice.
A screening result is not a diagnosis. Confirm any positive screen with a full nutrition assessment and follow your local policy. This tool runs entirely in your browser and no data is sent anywhere.
MST — Ferguson M, Capra S, Bauer J, Banks M, Nutrition 1999;15(6):458–464. 'MUST' is © BAPEN; we describe it here but do not reproduce it — use BAPEN's own calculator. Instruments named on this page remain their authors' work. See our Attributions and Data Sources.
MST is a two-question screen. It adds an appetite score and an unintentional weight loss score.
MST result
Enter the details to see the risk category and guidance.
These are all validated screens, and the differences between them are mostly about what you can measure rather than how well they work. If your health service mandates one, use that one — consistency across a service is worth more than the margin between validated tools.
MST
Malnutrition Screening Tool
MUST
Malnutrition Universal Screening Tool
MNA-SF
Mini Nutritional Assessment – Short Form
NRS-2002
Nutritional Risk Screening 2002
We reproduce MST above because we can attribute it precisely. For the others, use the publisher's own version — it is the current, correct scoring, and it is what your audit trail should point at.
Screening exists to divide a caseload into "needs a full nutrition assessment" and "does not, for now". It is built to be sensitive rather than precise, so it will flag people who turn out to be adequately nourished. That is the design working, not the tool failing.
Malnutrition itself is diagnosed on assessment, against criteria such as GLIM, by a dietitian. A screening score is never the diagnosis and should not be recorded as one.
Nutritional risk moves. A screen taken on admission says nothing about the same patient after a week of poor intake, a new acute illness, or a change in swallowing or appetite. Most policies set re-screening at a fixed interval for exactly this reason.
Re-screen sooner when the clinical picture changes rather than waiting for the interval to come round.
Spend the time on the patient
Screening, assessment, PES diagnosis, meal plans and chart-ready notes for Australian dietitians. Start your 14-day free trial.
FAQ
Screening is a short, standardised check that sorts people into "needs a full nutrition assessment" and "does not, for now". It is deliberately quick and deliberately blunt: a screen is designed to be sensitive rather than precise, so it will flag people who turn out to be well nourished, and that is the correct trade-off. A screen never diagnoses malnutrition. Diagnosis needs a full nutrition assessment against criteria such as GLIM, carried out by a dietitian.
It depends on what you can measure and who you are screening. MST asks two questions about appetite and unintentional weight loss, needs no measurements, and is widely used in Australian acute care. MUST adds measured BMI and an acute disease effect, so it suits settings where height and weight are already recorded. MNA-SF is designed for older adults. NRS-2002 is common in European hospital practice. Your health service almost certainly mandates one of them, and consistency across a service matters more than the choice between validated tools.
BAPEN publishes MUST, the MUST Explanatory Booklet and an official online calculator on its own site, and that is the authoritative source. We do not reproduce the MUST instrument here. BAPEN sets the terms on which MUST may be reproduced and asks to be approached about incorporating it into electronic systems, so using their published version means you are working from the current, correct scoring.
MST adds an appetite score (1 if appetite has decreased, otherwise 0) and a weight loss score (0 for none, 1 for 1 to 5 kg, 2 for 6 to 10 kg or if unsure, 3 for 11 to 15 kg, 4 for more than 15 kg). A total of 2 or more means the person is at risk of malnutrition and should be referred to a dietitian for a comprehensive nutrition assessment. Screening only, follow your local policy.
Act rather than observe. Refer to a dietitian or nutrition support team, or start your local nutrition pathway, agree explicit intake goals, and review progress against them at a stated interval. The screen has done its job at that point; what changes outcomes is the assessment and the plan that follow it. Record the screening result and the action taken, since an unactioned positive screen is a documented risk rather than a managed one.
Follow your local policy, which usually sets screening on admission and then at a fixed interval, commonly weekly for inpatients and at each review in the community. Nutritional risk is not static, and a negative screen only describes the day it was taken. Re-screen sooner if the clinical picture changes, particularly after a period of poor intake, a new acute illness, or a change in swallowing or appetite.
Every answer is general information only. MUST and MST are screening tools, not diagnostic tools. Confirm a positive screen with a full nutrition assessment and follow your local policy.