Malnutrition Screening Tool (MST)
Also known as: MST, Malnutrition Screening, Nutritional Risk Screen
The Malnutrition Screening Tool (MST), developed by Michelle Ferguson and colleagues in 1999, is a brief, validated screening instrument designed to identify hospitalized patients at risk for malnutrition. The tool consists of two simple questions about recent unintentional weight loss and reduced food intake, yielding a quick numerical score. Since its publication, the MST has become widely adopted in acute hospitals, residential aged care facilities, and community settings as a rapid, reliable first-line screen for nutritional risk.
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When to use it
Administer the MST to all patients on admission to acute hospitals and to residents on admission to long-term care facilities. Screens are particularly important for: older adults (age ≥65), patients with cancer or other chronic diseases, post-surgical patients, those with feeding difficulties or swallowing disorders, and anyone with visible weight loss or appetite loss. Rescreening at intervals (monthly in hospitals, quarterly in long-term care) or after significant clinical change (new illness, medication change, loss of independence) helps detect emerging nutritional risk.
Strengths & limitations
- Simplicity and speed—only two items, <2 minutes to administer; no calculation or special training required; universally applicable to diverse populations.
- High sensitivity and specificity—identified >95% of malnourished patients in validation studies; good positive predictive value for nutritional risk.
- Evidence-based development—created through systematic comparison to detailed nutritional assessment (anthropometry, biochemistry) and validated in multiple populations.
- Practical and actionable—readily administered at bedside or during admission; results directly guide dietitian referral and intervention intensity.
- Widely accepted—endorsed by major nutrition and healthcare organizations; incorporated into many hospital and care facility admission protocols.
- No copyright restrictions—freely available in the public domain.
- Self-reported weight loss accuracy—patients may not recall weight or appetite changes accurately; older adults with cognitive impairment may provide unreliable responses.
- Does not measure current nutritional status—the MST screens for risk but does not provide detailed assessment of protein, micronutrient, or fluid status; detailed nutritional assessment by dietitian is required for comprehensive evaluation.
- Limited discrimination in acute critical illness—critically ill patients may have altered appetite and reduced intake as normal acute response rather than true malnutrition; MST should be supplemented with anthropometric and biochemical measures in ICU.
- Does not capture all risk factors—causes of malnutrition other than weight loss and appetite (poor dentition, swallowing difficulty, medication effects, food access, cultural preferences) are not explicitly assessed.
Frequently asked
Should all hospitalized patients be screened with the MST?
Yes. The MST is recommended as a universal screening tool on hospital admission for all patients. It takes <2 minutes and has minimal burden, while identifying those at nutritional risk who would benefit from dietitian evaluation. Some hospitals use streamlined or electronic versions to facilitate routine use.
My patient scored MST 2 (at risk). What do I do next?
Refer to a dietitian for comprehensive nutritional assessment, including dietary history, appetite evaluation, swallowing assessment if indicated, and anthropometric/biochemical measures. Based on detailed assessment, the dietitian will recommend interventions: optimized diet, oral supplements, tube feeding, or other modalities. Monitor nutritional intake and reassess regularly.
What if my patient cannot remember weight changes or appetite history?
Interview collateral sources (family member, caregiver, previous medical records) for weight and appetite information. In cognitively impaired patients, caregiver report is often more reliable than patient self-report. Consider supplementing MST with anthropometric measures (current weight, height, BMI) and visual assessment of appetite and intake.
Is MST adequate for detailed nutritional assessment?
No. The MST is a screening tool only; positive screens trigger referral for comprehensive nutritional assessment by a registered dietitian. Detailed assessment includes dietary history, biochemical markers (albumin, prealbumin, hemoglobin), physical examination, functional assessment, and identification of treatable barriers to nutrition (dental problems, medication effects, food access).
Sources
- Ferguson, M., Capra, S., Bauer, J., & Banks, M. (1999). Development of a valid and reliable malnutrition screening tool for adult acute hospital patients. Nutrition, 15(6), 458-464. DOI: 10.1016/S0899-9007(99)00084-2 ↗
- Stratton, R. J., Hackston, A., Longmore, D., Dixon, R., Price, S., Stroud, M., King, B., & Elia, M. (2004). Malnutrition in hospital outpatients and inpatients: prevalence, concurrent validity and ease of use of the 'Malnutrition Screening Tool' (MST) for adults. Br J Nutr, 92(5), 799-808. DOI: 10.1079/BJN20041258 ↗
How to cite this page
ScholarGate. (2026, June 3). Malnutrition Screening Tool (MST). ScholarGate. https://scholargate.app/en/nursing/malnutrition-screening-tool
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