UWL: Screening and Assessment Methods (2009)

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

To determine whether the Mini Nutritional Assessment (MNA) can predict hospital stay outcomes in older individuals.

Inclusion Criteria:
  • Patients admitted to a tertiary-care geriatric hospital between February 1996 and January 1998
  • Patients who had a complete MNA on admission.
Exclusion Criteria:

None specifically mentioned.

Description of Study Protocol:


Patients were admitted to a tertiary-care geriatric hospital between February 1996 and January 1998. 1,145 out of 4,677 admissions to the hospital had an MNA completed (24% of the admissions).


Prospective cohort.


Assessment was done on admission and studied in relation to length of stay and in-hospital mortality for all patients, and discharge to a nursing home for those living at home before admission. The MNA was administered by the physician, except for the dietary questionnaire, which was completed by dietitians. The MNA has a maximum possible score of 30 points; patients are classified as well-nourished (score of 24 to 30), at risk for malnutrition (17 to 23.5), or malnourished (less than 17).

Statistical Analysis

  • Frequencies were analyzed using the Chi-square test
  • Means were compared using analysis of variance when the continuous variables were normally distributed. Otherwise, groups were compared using Kruskal-Wallis test.
  • Linear regression was used to evaluate the relation between MNA scores and age
  • Bonferroni's correction for multiple comparisons was applied when assessing the relationship between outcomes and the 18 individual items of the MNA; thus, the P threshold value was set to 0.00028 for these analyses (0.05 divided by 18).
Data Collection Summary:

Timing of Measurements

Patients admitted between February 1996 and January 1998. Assessment was done on admission and studied in relation to length of stay and in-hospital mortality for all patients, and discharge to a nursing home for those living at home before admission. 

Dependent Variables

  • Length of stay
  • In-hospital mortality
  • Discharge to nursing home.

Independent Variables

MNA, comprised of 18 items, including anthropometric measurements, global assessment, dietary questionnaire and subjective assessment.


Description of Actual Data Sample:

Initial N: 1,319 patients

Attrition (final N): 1,319 patients, 70% women. 1,145 complete assessments were available for analysis

Age: Mean age, 84.2 years

Ethnicity: Not mentioned

Anthropometrics: Patients in the groups with and without an available complete MNA were similar in terms of sex distribution, age, marital status and percentage discharged to a nursing home. However, there were more hospital deaths and a slightly shorter length of stay in the group without an MNA.

Location: Switzerland.

Summary of Results:



MNA<17 (n=213) MNA 17 to 23.5 (n=688) MNA>24 (n=244) All (n=1,145) P value

In-hospital death, %

11.3 6.8 3.7 80 <0.01

Mean length of stay, days


50.4±42.0 40.7±36.1



Median length of stay, days 42.0 36.5 30.5 36 ---

Other Findings

Of the 1,145 patients with a completed MNA, 7.0% died in the hospital, and 12.8% were discharged to a nursing home.

MNA scores averaged 19.9±3.8 with a range of 8.0 to 27.5 and a median of 20.5.

A score less than 17, corresponding to malnutrition, was associated with an almost threefold increase in mortality and in the rate of discharge to a nursing home; this contrasted with a score more than 24, which indicates satisfactory nutritional status (11.3% vs. 3.7%, P<0.01 and 20.3% vs. 7.7%, P<0.001, respectively).

Length of stay was longer in the low-scoring group (42.0 days vs. 30.5 days, P<0.0002). 

Individual MNA items were not associated with hospitalization outcomes.

Mid-arm and calf circumference measurements were associated with an increased risk of in-hospital death, whereas neuro-psychological problems and the ability to live independently were associated with a higher rate of nursing home transfer, and five items were related to a longer length of stay.

Author Conclusion:

Poor nutritional status as measured by the MNA was associated with increased in-hospital mortality, a higher rate of discharge to nursing homes and a longer length of stay.

Funding Source:
Other: Not described
Reviewer Comments:

Only 24% of all admitted patients were assessed. Patient selection methods not described. There were more hospital deaths and a slightly shorter length of stay in the group without an MNA

Authors note the following limitations: MNA was not completed for every patient admitted, and there was no randomization between patients who underwent the MNA and those who did not.

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? ???
  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? ???
  2.2. Were criteria applied equally to all study groups? ???
  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? ???
3. Were study groups comparable? ???
  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? ???
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) ???
  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? ???
  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.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? ???
  4.1. Were follow-up methods described and the same for all groups? No
  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%.) ???
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? No
  4.4. Were reasons for withdrawals similar across groups? ???
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
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? N/A
  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? N/A
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? N/A
  6.6. Were extra or unplanned treatments described? N/A
  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? N/A
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? N/A
  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)? N/A
  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? Yes
  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