UWL: Screening and Assessment Methods (2009)

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

The purpose of the study was to create an assessment tool (Mini-Nutritional Assessment Short Form; MNA-SF) that preserves diagnostic accuracy while minimizing the time and training needed for administration and is therefore brief enough for widespread screening.

Inclusion Criteria:

Not applicable

Exclusion Criteria:

Not applicable

Description of Study Protocol:

Recruitment

  •  Used three populations to develop and test the MNA-SF
    • Individuals from the database from the Toulouse-91, the original French population on whom the Mini-Nutritional Assessment (MNA) was developed
    • Individuals from a population in Mataro, Spain that had completed the full MNA
    • Individuals from a population in Albuquerque, New Mexico that were participants in the New Mexico Aging Process Study.

Design

  • The original MNA forms were completed during the three initial studies (described elsewhere) which examined these populations
  • The MNA-SF was developed from the database of information for the French participants
  • The MNA-SF was subsequently tested using the databases of information from the Spanish and New Mexico participants.

Blinding used

  • France
    • During the initial study, physicians conducting the assessment of clinical nutrition status did not know the MNA score results for those participants
  • No other blinding is reported.

Intervention

  • Developed MNA-SF questions utilizing data from French participants
  • MNA-SF subsequently tested on Spanish and New Mexico participants.

Statistical Analysis

  • Pearson correlations were examined between each item and the MNA total score
  • MNA inter-item correlations
  • Item analysis procedures to examine internal consistency for all MNA items
  • Sensitivity for each item and for the final MNA-SF
    • Compared against MNA, physician-judged clinical nutritional status and low serum albumin
  • Specificity for each item and for the final MNA-SF
    • Compared against MNA, physician-judged clinical nutritional status and low serum albumin
  • Diagnostic accuracy for each item and for the final MNA-SF
    • Compared against MNA, physician-judged clinical nutritional status and low serum albumin
  • Threshold values for MNA-SF were chosen using receiver-operating curves (ROCs) of diagnostic accuracy
  • Validation of MNA-SF
    • Stepwise discriminant analysis on all 18 items from MNA using 50% random sample of total participants and cross-validating with remaining 50% of participants.
Data Collection Summary:

Timing of Measurements

  • The timing of the initial data collection for the MNA forms is not described
  • The MNA-SF questions were determined and tested using the database information from previously conducted studies. 

Dependent Variables

Mini-Nutritional Assessment Short Form (MNA-SF)

Independent Variables

  • Independent physician rating of clinical nutritional status (France)
  • Mini-Nutritional Assessment (MNA; 18-item; Spain and New Mexico).

Control Variables

 None

Description of Actual Data Sample:

 Initial N

  France Spain New Mexico Combined
Hospitalized or sub-acute convalescent unit geriatric patients 105 114  0 219
Long-term care or nursing home 0 89 1 90
Independent community-dwelling individuals 50 199 346 595
Total N 155 402 347 904

 Attrition (final N)

  • Participants with complete MNA
    • France 151
    • Spain 400
    • New Mexico 330
    • Total 881.

Age

  • Mean age
    • France 78.3 years
    • Spain 75.8 years
    • New Mexico 76.8 years.

Ethnicity

Not provided

Other relevant demographics

  France Spain New Mexico Combined
Percentage (%)        

Female

66 61 60 61.4

Male

34 39 40 38.6
Albumin (mg/dL), Mean (SD) 3.30 (0.70) 3.76 (0.67) 4.09 (0.31) 3.83 (0.61)

Below 3.0 (%)

34.8 11.2 0.3 11.0

3.0 to 3.5 (%)

21.3 26.8 2.0 12.5

Above 3.5 (%)

43.9 62.0 97.7 76.4
Mean MNA score (SD) 19.9 (6.9) 23.3 (5.0) 25.7 (2.4) 23.6 (5.0)

Normal (≥24) (percentage)

35.1 58.8 81.5 63.2

At Risk (17-23.5) (percentage)

28.5 30.3 18.2 25.5

Undernourished (less than 17) (percentage)

36.4 11.0 0.3 11.2

 

France

  • 56% had a Folstein mini-mental state of less than 24 out of 30
  • 43% had a Katz Activities of Daily living score less than four out of six 
  • 49% reported anorexia
  • 43% were taking more than three medications.

Anthropometrics

  • BMI (mean (SD))
    • France 22.3 (4.4)
    • Spain 27.3 (5.0 )
    • New Mexico 25.2 (3.7).

Location

  • France
  • Mataró, Spain
  • Albuquerque, New Mexico.

 

Summary of Results:

MNA Items: Correlation with total MNA score and diagnostic characteristics relative to clinical nutritional status
(n=142 from French participants)

 

Item Content Pearson r with MNA total score Sensitivity Specificity Accuracy Χ2
1 BMI less than 23  0.698  0.795  0.774  0.787  53.06
2 Mid-arm circumference ≤22  0.317  0.125  1.000  0.454  7.18
3 Calf circumference less than 31  0.598  0.614  0.960  0.745  45.82
4 Recent weight loss greater than 1kg  0.750  0.875  0.774  0.837  62.69
5 Lives in nursing home or hospital  0.121  0.483  0.604  0.528  1.04
6 Prescription medications greater than three per day  0.307  0.584  0.755  0.648  15.38
7 Acute illness or stress  0.781  0.910  0.906  0.909  92.56
8 Housebound  0.799  0.775  0.925  0.831  67.79
9 Dementia or depression  0.700  0.652  0.943  0.761  48.03
10 Pressure sore or ulcers  0.556  0.416  0.981  0.627  26.69
11 Less than three meals per day  0.288  0.122  0.962  0.489  7.35
12 Less than three protein sources per day  0.333  0.588  0.736  0.645  15.17
13 Less than two servings of vegetables or fruit per day  0.279  0.165  1.000  0.486  9.72
14 Appetite loss or eating difficulty  0.743  0.775  0.981  0.852  76.05
15 ≤ five cups fluid per day  0.454  0.565  0.792  0.652  17.48
16 Self-fed with difficulty or unable  0.691  0.472  0.981  0.690  32.46
17 Moderate or major malnutrition  0.731  0.652  0.962  0.768  51.33
18 Health worse or don't know  0.515  0.618  0.887  0.718  35.92
             
MNA 18-item      0.989  0.943  0.972  125.41
MNA-SF 6-item    0.969  0.987  0.943  0.965  121.38

Other Findings

  • Six items with the highest sensitivity and overall accuracy were selected for the initial MNA-SF
  • Successively deleting items in the item analysis yielded the same six-item scale
    • Internal consistency MNA-SF (alpha coefficient) 0.843
    • Internal consistency full MNA (alpha coefficient) 0.865.

French Population (development of MNA-SF)

  • MNA-SF compared to full MNA
    • Sensitivity 97.9%
    • Specificity 100%
    • Diagnostic accuracy 98.7%
  • Comparison to clinical nutrition assessment for detecting persons who are undernourished
    • MNA-SF diagnostic accuracy 97.2%
    • Full MNA diagnostic accuracy 96.5%
  • Comparison to albumin
    • MNA-SF Pearson correlation, r=0.679
    • Full MNA Pearson correlation, r=0.699
    • MNA-SF diagnostic accuracy 98.7%.

Total Population (testing of MNA-SF)

  • MNA-SF vs. MNA
    • Pearson correlation, r=0.945 (P<0.0001)
    • Using greater than 11 as cutpoint for normal nutrition on MNA-SF, MNA-SF ability to predict malnutrition on full MNA:
      • MNA-SF sensitivity 97.9%
      • MNA-SF specificity 100%
      • MNA-SF diagnostic accuracy 98.7%.

Discriminant Analysis

  • Performed in two 50% random samples of the total population
    • Five of six of the MNA-SF items were selected among the first seven to enter the stepwise analysis (steps one, two, four, six and seven)
    • All six MNA-SF items were significant at P<0.0001
  • Performed in the Spanish and New Mexico populations
    • Five of six of the MNA-SF items were selected among the first seven to enter the stepwise analysis (steps one, two, three, five and six)
    • All six MNA-SF items were significant at P<0.0001
    • 87.9% of cases were correctly classified according to their full MNA score category.

 

Author Conclusion:
  • The MNA-SF has six questions and can be administered in approximately three minutes
  • The MNA-SF has high diagnostic accuracy relative to clinical nutritional status, high correlation with the full MNA
  • The MNA-SF is as good as the MNA in predicting serum albumin.
Funding Source:
Government: U.S. Department of Veterans Affairs
Industry:
Reviewer Comments:

This is a well designed study using a large population to develop and test the MNA-SF.

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? No
  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? ???
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? No
  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.) ???
  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? 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.) N/A
  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? Yes
  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? 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? Yes
  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)? Yes
  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