Unintended Weight Loss in Older Adults

UWL: Screening and Assessment Methods (2009)

Citation:

Thorsdottir I, Jonsson PV, Asgeirsdottir AE, Hjaltadottir I, Bjornsson S, Ramel A. Fast and simple screening for nutritional status in hospitalized, elderly people. J Hum Nutr Diet. 2005; 18: 53-60.

PubMed ID: 15647099
 
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:

Purposes of the study were to:

  • Evaluate two nutrition screening tools for elderly people, the Mini Nutrition Assessment (MNA) and the screening sheet for malnutrition (SSM)
  • Investigate whether a new sensitive and specific nutritional screening method for elderly hospitalized people could be constructed by combining significant questions from the different tools. 
Inclusion Criteria:

Age more than 65 years.

Exclusion Criteria:
  • Severe cognitive impairment
  • Failure to consent to anthropometric measurements.
Description of Study Protocol:

Recruitment

60 patients from the Department of Geriatrics were randomly assigned to participate in this study.

Design

Cross-sectional study. Patients were evaluated using the Mini Nutrition Assessment and a locally developed tool (SSM). Results were compared to the full nutrition assessment and factors highly correlated with the results of the full nutrition assessment were used to develop a new screening tool. 

Statistical Analysis

  • Sensitivity, specificity and predictive values were calculated to evaluate the screening tools and individual parameters
  • Cut-off values were tested for sensitivity and specificity and the best cut-off values chosen
  • The distribution of continuous variables was tested using the Kolmogorov-Smirnov test
  • Independent sample T-tests and cross-tabs with chi square statistics were used to assess the difference between malnourished and well-nourished patients as well as between men and women
  • The association between the screening methods and the FNA was calculated using cross-tabs, including the Phi coefficient. 
Data Collection Summary:

Timing of Measurements

 A single measurement during hospital admission.

Dependent Variables

  • Statement of height
  • Measurement of weight using standardized scales
  • Unintended weight loss based on the difference between recalled weight and weight at the time of study
  • Mid-arm circumference using a tape measure
  • Triceps skinfold thickness (in mm) using a Lange skinfold caliper
  • White blood cells using a Coulter STKS and the Coulter principle 
  • Lymphocytes using a Coulter STKS by volume-conductivity scatter
  • Serum albumin using colorimetry
  • Serum prealbumin using rate nephelometry
  • Full Nutrition Assessment score (FNA)
  • Mini Nutritional Assessment score (MNA)
  • Screening Sheet for Malnutrition (SSM).

Independent Variables

  • Sex
  • Malnutrition.

 

Description of Actual Data Sample:
  • Initial N: 60 hospitalized patients
  • Attrition (final N): 60
  • Age: 83±7.9 years
  • Other relevant demographics: 35% of the patients were malnourished on full nutrition assessment
  • Location: Reykjavik, Iceland.
Summary of Results:

Differences in Anthropometrical and Clinical Parameters Between Malnourished and Well-nourished Patients Based on Full Nutrition Assessment (FNA), Screening Sheet for Malnutrition (SSM) and Mini Nutrition Assessment (MNA)

Variable

Group (N=60)

Value

P-value

Age (years)

Malnourished (N=35)

85.6±7.4

0.002

 

Well-nourished (N=25)

79.3±7.1

 

BMI (kg/m-2)

Malnourished (N=35)

22.9±4.7

0.001

 

Well-nourished (N=25)

27.2±5.0

 

Unintended weight loss (yes in percentage)

Malnourished (N=35)

46.8

0.001

 

Well-nourished (N=25)

 

 

Albumin (g per  L-1)

Malnourished (N=35)

31.7±3.0

0.012

 

Well-nourished (N=25)

33.9±3.5

 

Prealbumin (mg per L-1)

Malnourished (N=35)

222±67

0.009

 

Well-nourished (N=25)

274±78

 

Total lymphocyte count (x109 per L-1)

Malnourished (N=35)

1.51±0.58

0.003

 

Well-nourished (N=25)

2.03±0.72

 

Mid-arm muscle circumference (cm)

Malnourished (N=35)

21.6±4.3

0.008

 

Well-nourished (N=25)

24.5±3.5

 

Triceps skinfold (mm)

Malnourished (N=35)

17.0±5.4

0.004

 

Well-nourished (N=25)

22.1±7.4

 

Recent surgery (yes in percentage)

Malnourished (N=35)

20.0

0.017

 

Well-nourished (N=25)

0

 

Loss of appetite (yes in percentage)

Malnourished (N=35)

51.4

0.014

 

Well-nourished (N=25)

20.0

 

 

 

 

 

 

 

 

 

 

 

 

 

Linear Regression for the Prediction of Full Nutrition Assessment (Dependent Variable) Score

 
Unstandardized
Coefficients
Standardized
Coefficients
 
 
B
SE
Beta
T
P-value
95% CI
Constant
1.943
0.664
 
2.928
0.005
0.613 to 3.273
Unintended weight loss
1.538
0.281
0.491
5.480
0.000
0.976 to 2.101
BMI
0.096
0.024
0.360
3.995
0.000
0.048 to 0.144
Surgery
-0.952
0.383
-0.217
-2.486
0.016
-1.719 to -0.184
Loss of appetite
-0.582
0.267
-0.201
-2.183
0.033
-1.117 to -0.048

 

 

 

 

 

Full Assessment and Screening of Nutrition Status

 

 

All screening methods over-estimate malnutrition in elderly hospital patients.

 

 

Participants
Full Assessment Malnourishment
MNA Malnourishment
SSM Malnourishment
Simplified Model Malnourishment
All patients (N=60)
35 (58.3)
41 (68.3)
41 (68.3)
34 (56.7)
Male patients (N=22)
12 (54.5)
15 (68.2)
11 (50.0)
12 (54.5)
Female patients (N=38)
23 (60.5)
26 (68.4)
30 (78.9)
24 (63.2)
Values in parenthesis represent percentage. Significant association between full assessment and SSM (phi=0.515, P<0.001) and simplified model (phi=0.762, P<0.001), but not MNA (phi=0.079, P=0.542). SSM, screening for malnourishment; MNA, Mini Nutrition Assessment.
Other Findings
  • Malnourishment was diagnosed by FNA in 58.3% of the elderly patients, with no gender difference
  • Body mass index, unintended weight loss, recent surgery and loss of appetite were predictors of malnutrition in the regression model (R2 = 60.1%)
  • The sensitivity and specificity of the simplified regression model were 89% and 88%, respectively, which was more precise than MNA (77% and 36%) and SSM (89% and 60%).
Author Conclusion:

According to full nutrition assessment scores, malnutrition is frequent in elderly hospitalized patients. Four questions are sufficient to conduct precise nutritional screening for malnutrition in elderly hospitalized patients. This new tool should be verified in other samples. 

Funding Source:
University/Hospital: Department of Geriatrics, Landspitali University Hospital
Reviewer Comments:

Relatively small sample size. Authors note that from this study, it cannot be concluded that the new screening tool is valid for all patients and age groups. Therefore, it should be validated in other samples.

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? N/A
  2.3. Were health, demographics, and other characteristics of subjects described? No
  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? N/A
  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? N/A
  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? ???
  7.6. Were other factors accounted for (measured) that could affect outcomes? No
  7.7. Were the measurements conducted consistently across groups? ???
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)? ???
  8.6. Was clinical significance as well as statistical significance reported? ???
  8.7. If negative findings, was a power calculation reported to address type 2 error? Yes
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