Unintended Weight Loss in Older Adults

UWL: Nutritional Status (2009)

Citation:

Laporte M, Villalon L, Thibodeau J, Payette H. Validity and reliability of simple nutrition screening tools adapted to the elderly population in healthcare facilities. J Nutr Health Aging. 2001; 5 (4): 292-294.

PubMed ID: 11753498
 
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:

The purpose of this study was to assess the validity and reliability of two simple tools to screen for protein-energy malnutrition (PEM) risk among an elderly population in acute and long-term care facilities.

Inclusion Criteria:

Patients aged 65 years or older who were admitted or living in the acute care and geriatric assessment/long-term care units of Georges-L.-Dumont Hospital and the Villa Du Repos Nursing Home, Moncton, NB, Canada between May and October 1999.

Exclusion Criteria:

None provided.

Description of Study Protocol:
  • Recruitment: Eligible patients were randomly selected to enter the study
  • Design: Cross-sectional
  • Blinding used: Not known
  • Intervention: Two simple screening tools were administered simultaneously by a dietetic technician (DT) and a nurse.  Screening was repeated by the same DT in about five days
    • Screening tool #1: BMI and percent weight loss
    • Screening tool #2: BMI and albumin
  • A dietitian completed a full nutrition assessment. The assessment included anthropometrics, biochemical indicators, dietary history and physical exam (described in Laporte et al, 2001).
  • Statistical analysis:
    • Contingency tables on the classifications of the screening tools and in-depth nutritional assessments were used to calculate sensitivity, specificity, and overall predictive value (PV) of each simple screening tool (SYSTAT)
    • The percent agreement and the kappa statistic were used to determine reliability of the simple tools.
Data Collection Summary:

Timing of Measurements

  • Acute-care patients: Screened using simple tools within 24 hours of admission
  • Long-term care patients: Screened using simple tools at time of recruitment into the study
  • In both groups, a dietitian completed the full nutrition assessment within 24 hours following the simple screens.

Dependent Variables

  • Screening tool #1: BMI and percent weight loss (obtained from patient interview or medical chart if in long-term care or if patient could not be interviewed)
  • Screening tool #2: BMI (height and wieght obtained from patient interview or by medical chart if patient could not be interviewed) and albumin (laboratory results)

Independent Variables

Full nutrition assessment: Protocol described in above section.

Control Variables

Not applicable.

Description of Actual Data Sample:
  • Initial N: 142 subjects grouped by facility
    • Acute care (ACE): N=72 (female N= 2, male N=30)
    • Long-term care (LTCE): N=70 (female N=38, male N=32)
  • Attrition (final N): 142; no dropouts
  • Age:
    • ACE: 78.9±7.1 years
    • LTCE: 79.5±7.1 years
  • Ethnicity: Not reported
  • Other relevant demographics: Not reported
  • Anthropometrics: Not reported
  • Location: New Brunswick, Canada.

 

Summary of Results:

 

Variables

Acute Care (ACE)

Tool 1

%

Acute Care (ACE)

Tool 2

%

Long-term Care (LTCE)

Tool #1

%

Long-term Care (LTCE)

Tool #2

%

All Sample

Tool #1

%

All Sample

Tool #2

%

Sensitivity

75.0

91.7

78.1

84.4

76.8

87.5

Specificity

75.0

68.8

63.2 

60.5

69.8 

65.1
Overall PV 75.0 76.4 70.0 71.4 72.5 73.9
Inter-rater (% agreement) 84.7 93.1 80.1 88.6 0.60±0.07 (kappa) 0.76±0.06 (kappa)
Test-retest (% agreement) 78.4 70.8 81.6 88.9 0.59±0.07 (kappa) 0.79±0.05 (kappa)

Other Findings

  • Tool 1: BMI and percent weight loss over time; Tool 2: BMI and albumin
  • The overall predictive value of the tools were very similar (72.5% and 73.9% for Tools 1 and 2, respectively)
  • Overall, Tool 2 has a greater ability to predict the presence or absence of high nutritional risk (sensitivity 87.5% compared to 76.8% for Tool 1), but Tool 1 provides a higher specificity result (69.8% for Tool 1 vs. 65.1% for Tool 2) suggesting it can do a slightly better job distinguishing elderly not at high nutritional risk.
Author Conclusion:

The two simple screening tools show high levels of sensitivity (75% or higher), validity (70.0% or higher) and sensitivity (agreement 80% or greater), indicating they are able to predict the presence or absence of PEM in this group of acute-care and long-term care elderly in New Brunswick, Canada.   

Funding Source:
Government: Medical Research Fund of New Brunswick, Department of Health
Reviewer Comments:

The generalizability of this study was not discussed. The generalizability is limited to elderly in one city in New Brunswick, Canada.

Other limitations were:

  • It is not clear if the DT, nurse and dietitian conducting the assessments were blinded
  • Sometimes BMI was assessed based on patient interview and sometimes using medical charts
  • The two simple tools were able to identify the marasmic type of malnutrition while the full assessments identified a mixed version of PEM.
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? N/A
  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? No
  2.2. Were criteria applied equally to all study groups? ???
  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? ???
  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? ???
  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? ???
  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")? Yes
4. Was method of handling withdrawals described? N/A
  4.1. Were follow-up methods described and the same for all groups? N/A
  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%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? N/A
  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? ???
  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.) ???
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? No
  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? No
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? N/A
  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? 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? N/A
  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? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? N/A
  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)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? No
  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? No
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? No
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