UWL: Screening and Assessment Methods (2009)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

The aim of this study was to test the validity of the Mini Nutritional Assessment Short Form (MNA-SF) as a screening tool for malnutrition in elderly medical patients.

Inclusion Criteria:
  • 70 years of age or older
  • Length of stay in hospital of more than three days
  • Able to communicate verbally
  • Willing to give informed consent.
Exclusion Criteria:
  • Severe dementia
  • Terminal disease.
Description of Study Protocol:


  • Patients were from the general unit
  • Recruited between January 1, 2000 and October 31, 2001
  • Informed consent was obtained.


  • Cross-sectional study comparing the MNA-SF to the clinical nutritionist's assessment
  • The MNA-SF was performed by a study nurse
  • A clinical nutritionist performed a nutritional assessment of the same patient within three days of the nurse's assessment.

Blinding Used

The clinical nutritionist was blinded to the results of the MNA-SF scored by the nurse.

Statistical Analysis

  •  Results of the MNA-SF were compared with the clinical nutritionist's assessment:
    • Sensitivity
    • Specificity
  • Correlation analysis on MNA-SF items (polychoric and polyserial)
  • Logistic regression to identify independent items in clinical nutritionist's assessment
  • All analyses conducted by SPSS (version 11.0).
Data Collection Summary:

Timing of Measurements

  • When a patient met the inclusion criteria, the nurse performed and scored the MNA-SF
  • The clinical nutritionist assessed the same patients within three days of the completion of the MNA-SF.

Dependent Variables

MNA-SF completed by the nurse.

Independent Variables

Nutritional assessment completed by the clinical nutritionist, and was considered to be "gold standard" by researchers conducting the study.

Description of Actual Data Sample:
  • Initial N: 94 patients
  • Attrition (final N): 69 patients (final population only included the patients that the clinical nutritionist could assess)
  • Age: 81.5±5.6 years (mean ±SD).

Other Relevant Demographics

  • Reason for admission
    • 38% cardiac problems (included heart failure and chest pain with suspected or known coronary artery disease)
    • 25% geriatric syndromes (included falls, dehydration and delirium)
    • 12% infections
    • 11% chronic obstructive pulmonary disease
    • 3% malignancies
  • Average length of stay: 10.6±6.5 days
  • Serum albumin: 36.2±5.1g per L
  • C-reactive protein: 42.5±56.8mg per L


  • Weight: 62.9±14.7kg
  • Height: 164.5±8.6cm
  • BMI: 23.2±4.9kg/m2
  • Triceps skinfold: 15.5±7.6mm
  • Mid-arm muscle circumference: 23.0±3.4cm


Department of General Internal Medicine, Ullevaal University Hospital, Olso, Norway.

Summary of Results:





Correctly Classified Subjects

MNA-SF less than 11 correctly identifying clinical malnutrition




BMI less than 23 correctly identifying clinical malnutrition




MNA-SF and BMI less than 23 correctly identifying clinical malnutrition





Other Findings

  • 21 patients (30%) were scored as clinically malnourished by the clinical nutritionist
  • 51 patients (74%) were scored as malnourished or at risk of malnutrition by the MNA-SF
  • MNA-SF mean, 7.8±2.9 (range two to 12)
  • Correlational analyses (polychoric and polyserial) of BMI, weight loss, mobility, neuropsychological problems and food intake produced poor correlations (coefficients 0.07 to 0.34); therefore a factor analysis was not completed
  • Logistic regression analysis demonstrated that BMI was the best item to explain the "gold standard" (clinical nutritionist's assessment). BMI functioned best when dichotomized between highest value (BMI more than 22) and the remaining values.
Author Conclusion:
  • The MNA-SF can be used to screen elderly acute medical patients in general wards for malnutrition or risk of malnutrition
  • The method has a high sensitivity, reproducibility and inter-observer agreement when used by nurses and is easy and not too time-consuming to perform
  • If the aim is to screen patients for a poor nutritional status, BMI less than 23 may be a better method, but will give no additional information about possible causes for the compromised nutritional status
  • The authors recommend that a positive score of BMI less than 3 should be followed by MNA-SF when the aim is to identify poor nutritional status in elderly acute medical patients in a general ward.
Funding Source:
Other: Unknown
Reviewer Comments:
  • This appears to be a well-conducted study that clearly defines inclusion and exclusion criteria for the population utilized
  • Use of the term "gold standard" for the clinical nutritionist's assessment could be misleading.
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? Yes
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) Yes
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? Yes
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? Yes
5. Was blinding used to prevent introduction of bias? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? Yes
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? Yes
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? Yes
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? No
  6.6. Were extra or unplanned treatments described? No
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  6.8. In diagnostic study, were details of test administration and replication sufficient? Yes
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? No
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? No
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? N/A
  8.6. Was clinical significance as well as statistical significance reported? No
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes