Unintended Weight Loss in Older Adults

UWL: Screening and Assessment Methods (2009)

Citation:

Langkamp-Henken B, Hudgens J, Stechmiller JK, Herrlinger-Garcia KA. Mini nutritional assessment and screening scores are associated with nutritional indicators in elderly people with pressure ulcers. J Am Diet Assoc. 2005; 105: 1,590-1,596.

PubMed ID: 16183360
 
Study Design:
Cross-Sectional Study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To determine the association between the Mini Nutritional Assessment (MNA) or MNA Screening Form and standard indicators of nutritional status in male elders with pressure ulcers.

Inclusion Criteria:
  • Resident of the Veterans Affairs Medical Center Nursing Home Units in two Southeastern cities
  • Aged 65 years or older
  • Had stage II or more severe pressure ulcer.
Exclusion Criteria:
  • Diabetes treated by insulin
  • Renal failure (serum creatinine greater than 220μmol/L)
  • Hepatic failure (abnormally elevated liver enzymes)
  • Evidence of a systemic infection
  • An immune deficiency disease
  • Received immunosuppressive medications.
Description of Study Protocol:

Recruitment

Data were collected prospectively and represent the baseline data from subjects enrolled in an intervention trial on protein or nitrogen-containing supplements.

Design: Cross-Sectional Study 

Statistical Analysis

  • MNA and MNA Screening Form scores were related to nutritional indicators using the Pearson correlation 
  • Canonical correlation procedures were used to assess the relationship between the weighted sum of two sets of variables (i.e. MNA and MNA Screening Form and BMI, BCM index, extracellular mass index and fat mass index)
  • Relationships were quantified using the correlation coefficient.
Data Collection Summary:

Timing of Measurements

All information collected at baseline from subjects enrolled in intervention trial

Dependent Variables

  • Biochemical indices of nutritional status: Blood samples drawn for analysis of serum albumin and prealbumin, total lymphocyte count, hematocrit, hemoglobin, blood urea nitrogen, serum electrolytes and creatinine and erythrocyte sedimentation rate
  • Anthropometric indices of nutritional status: Weight, height and BMI
  • Measures of body composition determined by single frequency bioelectrical impedance analysis and normalized for height by dividing height in meters2.

Independent Variables

  • Mini Nutritional Assessment (MNA): All questions
  • MNA Screening Form: Six questions.

Control Variables

Demographic data and information on pressure ulcers were obtained from the medical record

Description of Actual Data Sample:

Initial N

30 subjects were initially recruited but only 28 met inclusion and exclusion criteria. Four withdrew before initiating study procedures, leaving 23 males and one female. Due to differences between males and females, the one female was omitted from analyses.

Attrition (final N): 23 males

Age: 79±1 years

Ethnicity: 11 White, 12 African American

Other relevant demographics

Median three pressure ulcers per subject (range one to six)

Location: Veterans Affairs Medical Center Nursing Home Units in two Southeastern cities

 

Summary of Results:

 

Assessment Tool Well-nourished (n=3) At risk for Malnutrition (n=7) Malnourished (n=13)

MNA Screening Form score

12.3±0.9 9.1±0.6 4.8±0.5
MNA score 24.5±0.7 19.4±0.8 12.5±0.8
Anthropometric assessment 7.3±0.3 6.3±0.5 3.8±0.3
Global assessment 5.0±1.1 2.7±0.4 1.1±0.4
Dietary assessment 8.7±0.3 7.9±0.3 6.2±0.5

Subjective assessment

3.7±0.3 2.6±0.4

1.4±0.3

Other Findings

  • When nutritional status of the subjects was determined using the MNA, only three out of the 23 subjects were considered well nourished, whereas 20 were considered at risk for malnutrition or malnourished
  • Hemoglobin (mean 106±4g/L; r=0.43, P=0.0409), hematocrit (mean 0.32±0.01; r=0.44, P=0.0358), body mass index (mean 23.1±1.0, r=0.66, P=0.0006), calf circumference (mean 30.4±1.1cm; r=0.46, P=0.0286), fat-free mass index (mean 18.3±0, r=0.60, P=0.0063), body cell mass index (mean 8.3±0.5, r=0.64, P=0.0033), and fat mass index (mean 3.7±0.4, r=0.50, P=0.0275) positively correlated with MNA score
  • Serum albumin (31±1g/L) and prealbumin (180±17mg/L) did not correlate with MNA, but prealbumin inversely correlated with erythrocyte sedimentation rate (r= -0.52, P=0.0134), a marker of inflammation
  • The inverse correlation between albumin and erythrocyte sedimentation rate approached statistical significance (r= -0.42, P=0.0542)
  • The MNA Screening Form showed similar correlations or lack of correlations observed with the MNA with the exception of hemoglobin and hematocrit.   
Author Conclusion:

The majority of elders in this study were at risk for malnutrition or malnourished when assessed by the MNA and as indicated by comparison of nutritional indicators to national norms or previous studies. The MNA score correlated positively with anthropometric measures, hemoglobin, and hematocrit and inversely with measures of hydration status.

The MNA Screening Form score was also positively associated with anthropometric measures and inversely associated with measures of hydration status. In addition, the MNA Screening Form identified all subjects as possibly malnourished who were classified as malnourished or at risk for malnutrition by the MNA. Serum albumin and prealbumin did not correlate with MNA Screening Form and MNA scores. This lack of association may reflect inflammatory changes in visceral proteins typically associated with pressure ulcers. The MNA Screening Form and MNA provide an advantage over using visceral proteins in screening and assessing nutritional status of elders with pressure ulcers.

Funding Source:
Government: Florida Agricultural Research Station, grant R15 NR05056 from the National Institute of Nursing Research
Reviewer Comments:

Small sample size with only males. Authors note the following limitations:

  • Using bioelectrical impedance analysis to predict body composition requires well-hydrated subjects, and some of the subjects were dehydrated
  • All male subjects
  • Inclusion and exclusion criteria were those established for an intervention trial regarding the administration of large nitrogen loads and the assessment of immune function, not necessarily those with pressure ulcers.
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? 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? N/A
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  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? N/A
  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? 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? N/A
  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? N/A
  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? N/A
  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? ???
  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? N/A
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? ???
  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? ???
  7.7. Were the measurements conducted consistently across groups? N/A
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? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? No
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