Unintended Weight Loss in Older Adults

UWL: Nutritional Status (2009)

Citation:

Laporte M, Villalon L, Payette H. Simple nutrition screening tools for healthcare facilities: Development and validity assessment. Can J Diet Pract Res. 2001 Spring; 62(1): 26-34.

PubMed ID: 11518553
 
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 goal of the study was to develop a simple and valid tool (i.e., tool shows sensitivity, specificity and overall predictive value of 80% or greater) for screening PEM risk among adult and elderly inpatients and among the elderly in long-term care facilities.

The study set out to:

  • Identify significant risk factors, included in an initial screening tool comprising nine PEM risk factors
  • Assess the validity of two simple screening tools comprising the significant risk factors.
Inclusion Criteria:

Patients admitted to Cambellton Regional Hospital between May 1996 and August 1996 who were either:

  • Adults 64 or younger in acute care (ACA)
  • Adults 65 or older (elderly) in acute care (ACE).

Also, long-term care patients (LTCP) at the Village Campbellton Nursing Home.

 

Exclusion Criteria:
  • Patients admitted to the regional hospital acute care under obstetrics/gynecology and psychiatric units
  • Those with a diagnosis of MI.
Description of Study Protocol:

Recruitment

All those who met Inclusion or Exclusion criteria at the hospital were recruited. At the LTC facility, subjects were randomly selected from the pool of 100 residents. Each subject eligible to take part signed an informed consent form. Cognitively impaired elderly patients were included; consent was obtained through a family member.

Design

Cross-sectional; initial screen and full nutrition assessment for each patient were collected.

Intervention

Subjects underwent an initial screen and a full nutrition assessment.

Nine measures were used for the Initial PEM screening tool:

  • BMI
  • Percentage of weight loss over time
  • Albumin
  • Loss of appetite
  • Number of meals and snacks eaten per day
  • Difficulty chewing and swallowing
  • Problems with mouth, teeth or gums
  • Need for assistance with eating
  • Diagnosis and medical condition associated with PEM (criteria lists provided).

A dietetic technician administered the initial screening tool. Each measure was rated as Mild (one point), Moderate (two points), or Severe (three points) based on criteria for each (e.g., mild albumin, 28g to 35g per L; moderate, 22g to 27g per L; severe, less than or equal to 21g per L).

Ratings for each were summed to create the Nutrition Risk Classification numbers:

  • Zero to two points: Not at PEM risk
  • Three to five points: Mild PEM risk
  • Six to eight points: Moderate PEM risk
  • Nine or more points: Severe PEM risk.

The full nutrition assessments were conducted by two dietitians. Full nutrition assessments consisted of the following and were rated as none, mild, moderate and severe:

  • Anthropometric: BMI, percentage of weight loss over time, sum of two skinfolds (mm); TSF and SSSF and percentile and MAMA (cm) and percentile
  • Biochemical: Albumin, transferrin, lymphocyte count, Hgb, Hct, and Chol (mmol per L)
  • Dietary: Energy intake (kcal per day) and protein intake (g per day) less than 80% of the Recommended Nutrient Intakes for Canadians
  • Physical signs and symptoms associated with PEM: Hair, skin, musculoskeletal system, and face (parotid enlargement).

PEM was diagnosed when at least four nutritional indicators were abnormal, including:

  • Two anthropometric and two biochemical
  • Two anthropometric, one biochemical, one dietary
  • One anthropometric, two biochemical, one dietary

If PEM was diagnosed, the dietitian ranked each subject as mild, moderate or severe PEM using anthropometric and biochemical information unless physical signs were present. If physical signs were present, patient was labeled as severe.

Statistical Analysis

  • Energy and protein intakes were evaluated using Nutrient Analysis Program software
  • Logistic backward stepwise regression for all subjects was performed using SYSTAT to identify significant (P<0.05) risk factors to use in a simplified version of the initial screening tool
  • Contingency tables on the classifications of the screening tools and nutritional assessments were used to identify true positive, true negative, false positive, and false negative to calculate sensitivity, specificity and overall PV
  • ROC was drawn for each simple screening tool developed (curve determines screening tool cutoff point that provided the best sensitivity and specificity values).
Data Collection Summary:

Timing of Measurements

  • All acute care subjects were screened using the initial screener within 72 hours of admission, using patient interviews and chart reviews (biochemical data and diagnoses/medical conditions). LTC patients were screened as they were selected to participate.
  • Within 24 hours of the initial screen, a full nutrition assessment was completed.

Dependent Variables

Presence of PEM (yes or no) as measured by the dietitians' full nutrition assessments.

Independent Variables

All nine risk factors included in the initial screening tool.

 

Description of Actual Data Sample:

Initial N

160 in three age categories.

  • N=54 acute care adults age 64 or younger: ACA (42.6% male, 57.4% female)
  • N=57 acute care elderly age 65 or older: ACE (36.8% male, 63.2% female)
  • N=49 long-term care elderly: LTCE  (24.5% male, 75.5% female).

Attrition (Final N)

160.

Age

  • ACA: 46.4±12.2 years
  • ACE: 74.2±6.9 years
  • LTCE: 85.9±7.9 years.

Anthropometrics

Groups differed on BMI, albumin, main medical conditions associated with PEM, and prevalence of PEM (see results table).

Location

New Brunswick, Canada.

Summary of Results:

 

Variables

ACA (N=54)

Mean±SD or %

ACE (N=57)

Mean±SD or %

LTCE (N=49)

Mean±SD or %

All Sample

BMI (kg/m2)

Percentage with BMI less than 18.4 for adults and 24.0 for elderly

26.9±5.4

5.5

26.7±5.1

28

22.9±5.3

61.2

 

Percentage of subjects showing a weight loss

53.7

57.9 

42.9

 

Albumin (g per L)

Percentage subjects with Albumin less than or equal to 35

35.6±4.1

50

33.5±3.9

70.2

32.7±2.9

79.6

 
Main Medical Conditions Associated with PEM GI Disorders and Neurological Disorders Pulmonary Diseases and Cancer (Active) Cognitive Disorders and Neuro-rheum Disorders  

Prevalence of PEM

None

Mild

Moderate

Severe

29.6% overall

70.4%

18.5%

1.8%

9.2%

40.3% overall

59.6%

15.8%

5.3%

19.3%

61.2% overall

38.8%

20.4%

6.1%

34.7%

For all, 43.1%

56.9%

18.1%

4.4%

20.6%

         
Validity Indices Screening Tool #1/2*  (%) Screening Tool #1/2* (%) Screening Tool #1/2* (%) Screening Tool #1/2* (%)
Sensitivity 33.3/33.3 78.6/92.9 85.0/90.0 75.0/82.5
Specificity 81.3/97.9 76.7/83.7 75.9/44.8 78.3/80.0
Overall Predictive Value 75.9/90.7 77.2/86.0 79.6/63.3 77.5/80.6

 * Screening Tool #1 = BMI and percentage of weight loss over time; Screening Tool #2 = BMI and albumin level 

Other Findings

  • Four significant risk factors best identified subjects' nutritional status: BMI (P<0.001), diagnoses/medical conditions associated with PEM (P=0.006), albumin level (P=0.025), and percentage of weight loss over time (P=0.032). The four factors explained 53% of the variance in PEM existence.
  • In final screens, diagnoses/medical conditions were not included due to necessary extensive chart reviews
  • The final simple screen tool consisted of BMI and percentage of weight loss over time. Patients were categorized as low (none or mild; one point) or high (moderate or severe; two points) PEM risk for each of the two risk factors. A summed score of two or greater indicated high risk of PEM.
  • Weight is not always available; a second simple screening tool consisting of albumin and BMI was also tested
  • ROC curve: A score of two points provided the best validity for both simple screeners: 
    • Validity for ACA: Both screening tools had high specificity and overall PV (75.9% or higher) but low sensitivity
    • Validity for ACE: Simple screen one had validity of 77.2% (PV); albumin + BMI had higher validity (PV of 86.0%)
    • Validity for LTCE: Simple screen one had highest validity (79.6% PV); albumin + BMI had low specificity (44.8%). Not a valid screening tool in this population.
Author Conclusion:

The simple screening tools of BMI and percentage of weight loss, and albumin and BMI were valid measurements of PEM in adults admitted to acute-care settings, elderly admitted to acute-care settings, and elderly in a long-term care facility in New Brunswick, Canada. The simple tools lacked the sensitivity necessary for screening adults in acute care settings. Screening tool No. two lacks specificity in the long-term care population.

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

The generalizability of this study is limited. The ethnic composition of the sample is unknown but the sample was pulled from one location in New Brunswick, Canada. Generalizabilty was not discussed as a limitation.

The strength of the study was that the two dietitians completing the full assessments were trained and participated in a reliability study before data collection.

The limitations of the study were:

  • The two simple tools include risk factors that were used as nutritional indicators in the dietitians' assessments (BMI, weight loss, albumin)
  • Simple screens were validated with the same sample of subjects used to identify the significant factors
  • Researchers suspected only four initial factors were significant because of co-linearity (e.g., loss of appetite and BMI) but co-linearity was not reported or confirmed
  • MAMA is not recommended for the elderly, even with the bone correction
  • Despite the use of trained dietitians, no intraclass correlation was calculated in this study to assess reliability.

 

 

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? No
  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? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  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? No
3. Were study groups comparable? No
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) No
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? No
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) No
  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.) No
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? No
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? No
  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.) No
  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? 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? 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? 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? 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? 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? No
  8.1. Were statistical analyses adequately described and the results reported appropriately? No
  8.2. Were correct statistical tests used and assumptions of test not violated? ???
  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? No
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