ONC: Malnutrition Screening and Nutrition Assessment of Adult Oncology Patients (2012)

Citation:

Bauer J, Capra S, Ferguson M. Use of the scored Patient-Generated Subjective Global Assessment (PG-SGA) as a nutrition assessment tool in patients with cancer. Eur J Clin Nutr. 2002 Aug; 56 (8): 779-785. PMID: 12122555.

PubMed ID: 12122555
 
Study Design:
Cross-Sectional Study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
  • To evaluate the use of the scored Patient-Generated Subjective Global Assessment (PG-SGA) as a nutrition assessment tool in hospital patients with cancer
  • To compare the performance of the scored PG-SGA with SGA (sensitivity and specificity) and determine patient outcomes in terms of nutritional status.
Inclusion Criteria:

Patients with cancer, aged at least 18 years, admitted to an acute care medical facility were eligible for inclusion in the study over a three-month period.

Exclusion Criteria:

None.

Description of Study Protocol:

Recruitment

Subjects were recruited through admission to the oncology ward at a private tertiary care hospital.

Design

  • A dietitian experienced in performing subjective global assessment and using the scored PG-SGA assessed all patients
  • Each patient was classified as well-nourished (SGA A), moderately or suspected of being malnourished (SGA B) or severely malnourished (SGA C). In addition, a total PG-SGA score was calculated.
  • A retrospective review of the medical record provided information on age, gender, diagnosis, length of stay, re-admission or death within 30 days of discharge.

Blinding Used

Not applicable.

Intervention

Not applicable.

Statistical Analysis

  • The non-parametric Kruskal –Wallis test was used to compare median PG-SGA scores and median length of stay for each SGA classification.
  • A contingency table was used to determine the sensitivity, specificity and predictive value of the PG-SGA compared to SGA.
  • Reliability analysis was used to determine the extent to which items in the questionnaire were related to each other and provide an overall index of the internal consistency of the questionnaire.
  • Chi-square tests were used to examine the relationship between nutritional status and readmission and/or death within 30 days of discharge.
  • Correlation analysis was used to examine the relationship between PG-SGA score and both percentage weight loss in the previous 6 months and body mass index (BMI).
  • Multiple regression analysis was performed to examine the relationship between length of stay as the dependent variable and independent variables age, diagnosis, percentage weight loss, BMI and PG-SGA score.
  • Logistic regression was used to assess predictors of mortality within 30 days of discharge.

 

Data Collection Summary:

Timing of Measurements

  • SGA and PG-SGA were completed during hospitalization
  • A retrospective review of the medical record provided information on age, gender, diagnosis, length of stay, re-admission or death within 30 days of discharge.

Dependent Variables

PG-SGA score.

Independent Variables

  • SGA score
  • BMI
  • Percentage of weight lost over the past six months
  • Length of stay
  • Mortality within 30 days of discharge
  • Re-admission within 30 days of discharge.

Control Variables

Diagnosis of cancer.

Description of Actual Data Sample:
  • Initial N: 71
  • Attrition: 71 (40 male, 31 female)
  • Age: Average, 57.6±15.4 years
  • Ethnicity: Not stated.

Other Relevant Demographics

49% of patients were diagnosed with lymphoma, 13% with breast cancer and 4% for
cancers of the prostate, esophagus, lung, sarcoma and myeloma, respectively.

Anthropometrics

Body mass index (kg/m2)

  • SGA A (well-nourished): 26.2±4.0
  • SGA B (moderately nourished): 24.5±4.9
  • SGA C (severely malnourished): 19.4±2.2.

Location

Brisbane, Australia.

Summary of Results:

Nutrition Impact Symptoms

Percentage of Patients (N)
No Appetite
46.5% (33)
Nausea
38% (27)
Pain
29.6% (21)
No Problems Eating
28.2% (20)
Vomiting
28.2% (20)
Constipation
23.9% (17)
Things Taste Funny
22.5% (16)
Smells Bother Me
21.1% (15)
Diarrhea
21.1% (15)

Mouth Sores

19.7% (14)
Other
19.7% (14)

[Note: Patients could report more than one symptom.]

Classification of 71 Patients with Cancer, According to the Patient-Generated Subjective Global Assessment (PG-SGA) Score and Subjective Global Assessment (SGA)

 
Malnourished
(SGA B+C)
Well-Nourished
(SGA A)
At nutrition risk (PG-SGA score ≥9) True positive, 53 (75%) False positive, 3 (4%)
Not at nutrition risk (PG-SGA score 0-8) False negative, 1 (1%) True negative, 14 (20%)
  • Regression analysis determined that none of the variables age, diagnosis, percentage weight loss, BMI and PG-SGA score were significant predictors of LOS or mortality within 30 days of discharge. The final model for predictors of length of stay included PG-SGA score (F1,63=3.586, P=0.06), which accounted for 5% of the total variation in LOS.
  • The scored PG-SGA had a sensitivity of 98% and a specificity of 82%
  • The positive predictive value was 95% and the negative predictive value was 93%.

Age, Gender, Patient-Generated Subjective Global Assessment (PG-SGA) Score, Percentage Weight Lost in Previous Six Months, Body Mass Index, LOS and Re-Admission or Mortality Within 30 Days of Discharge for Subjective Global Assessment (SGA) Groupings in 71 Hospitalized Cancer Patients

SGA A Well-Nourished SGA B Moderately Malnourished SGA C Severely Malnourished

P-Value

Number of Patients (%)

17 (24)

42(59)

12 (17)
<0.001

Gender (M/F)

7:10

25:17

8:4

0.285

Age (Years)

50.1±13.6

56.5±14.9

71.8±9.4

<0.001

PG-SGA Score Median (Range)
5.0 (1-16)
14.0 (6-31)
19.5 (13-27)
<0.001
Percentage Weight Loss in Previous 6 Months Median (Range)
0 (0-14)
6.9 (0-16.9)
14.6 (3.7-22.4)
<0.001
Body Mass Index (kg/m2)
26.2±4.0
24.5±4.9
19.4±2.2
0.011
Length of Stay (Days), Median (Range)
7.0 (1-24)
14.0 (1-40)
9.5 (1-30)
0.063
Re-Admission Within 30 Days Discharge, N (%)
10 (59)
22 (52)
2 (17)
0.037
Mortality Within 30 Days Discharge, N (%)
1 (6)
5 (12)
3 (25)
0.305

There was a significant correlation between PG-SGA score and LOS (R=0.3, P=0.034).

Author Conclusion:
  • These results demonstrate that the scored PGSGA is a quick, valid and reliable nutrition assessment tool that enables malnourished hospital patients with cancer to be identified and triaged for nutrition support
  • Priority can be given to those patients identified as malnourished and the appropriate intervention initiated
  • The scored PG-SGA has several advantages as a nutrition assessment tool, in comparison to SGA for patients with cancer.
Funding Source:
University/Hospital: The Wesley Reseach Institute
Reviewer Comments:
  • Used a convenience sample but had a fairly large N
  • Not much information was given about the subjects
  • No blinding used.
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? ???
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? ???
  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) 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? Yes
  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? Yes
  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? 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? 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? 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? 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