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

Citation:

Persson C, Sjoden PO, Glimellius B. The Swedish version of the patient-generated subjective global assessment of nutritional status: gastrointestinal vs urological cancers. Clin Nutr. 1999; 18 (2): 71-77.

 
Study Design:
Diagnostic, Validity or Reliability Study
Class:
C - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
  • To translate the English version of the Patient-Generated Subjective Global Assessment (PG-SGA) into Swedish and to evaluate the instrument in an outpatient cancer setting
  • To determine if the instrument could be used by different professionals, was easy for patients to respond to and whether it had prognostic capabilities.
Inclusion Criteria:
  • Patients with gastrointestinal (GI) or urological (UR) tumors at an outpatient unit in Uppsala, Sweden
  • Had to provide written consent to participate; study approved by Research Ethics committee at the University of Uppsala.
Exclusion Criteria:

None specifically stated; any other type of cancer besides gastrointestinal or urologic.

Description of Study Protocol:

Recruitment

87 consecutive patients recruited from the outpatient unit of the Department of Oncology, Akademiska Hospital in Uppsala, Sweden were assessed using the PG-SGA.

Design

Validity study

  • PG-SGA was translated into Swedish, back-translated into English, then re-translated into Swedish upon comparison of the two versions
  • Patients completed the PG-SGA sections designed for patient use and responded to questions regarding clarity and usefulness of the items
  • Two physicians and one dietitian independently assessed patients with GI tumors, using the SGA classifications of A (well nourished), B (moderately or suspected of being malnourished) or C (severely malnourished) to determine agreement 
  • Three physicians and one dietitian independently assessed patients with UR tumors, using the SGA classifications of A, B or C to determine agreement
  • Biochemical measurements (serum albumin and pre-albumin) were taken on the participants and used to validate SGA classifications
  • Nutrition assessments were stratified by SGA classification and compared to biochemical measurements and responses to separate items on the PG-SGA instrument.

Statistical Analysis

  • Spearman correlation coefficient to determine relationship between self-reported weight loss and biochemical measurements
  • ANOVA to determine differences in biochemical measurements between the SGA classifications
  • T-test to determine differences in biochemical measurements between participants with loss of subcutaneous fat, muscle wasting and eating problems, as assessed by the practitioner
  • Log-rank test to determine survival between the classifications
  • Logistic regression to determine relationships between components of the instrument and SGA classification
  • Kappa statistic to determine inter-rater agreement.
Data Collection Summary:

Timing of Measurements

  • PG-SGA administered to patients once, after patients consented to participate
  • The physician and dietitian assessed the participants using the PG-SGA independently after patient consented
  • Biochemical measurements taken once; assumed at that same appointment. 

Dependent Variables

  • PG-SGA responses from participants; self-reported responses to four items regarding:
    • Weight change over past two weeks, six months, 12 months
    • Food intake during past month
    • Problems prohibiting intake over past two weeks
    • Functional capacity over past month.
  • PG-SGA responses from physicians and dietitian; assessed participants on items regarding:
    • Severity of disease
    • Physical appearance
    • SGA rating.
  • Serum albumin (g per L)
  • Serum prealbumin (g per L).

 Control Variables

  • Inequality in the number of participants assessed by each physician rater: 51 participants with GI tumors assessed by one physician and three participants assessed by another
  • 12 participants with UR tumors assessed by one physician, 12 participants assessed by another and eight by yet another.
Description of Actual Data Sample:

Initial and final N

  • 87 participants (54 with GI tumors, 33 with UR tumors)
  • 61 men and 26 women (not broken-down further).

Age

Median, 65 years (range, 21 to 80 years). No standard deviation; no further break-down.

Ethnicity

Not provided, assumed Swedish descent.

Other Relevant Demographics

  • 73 participants had no treatment at the time of assessment
  • 11 had chemo initiated
  • None had surgical intervention.

Anthropometrics

  • Only self-reported anthropometrics were provided
  • The group of 87 participants were classified into three groups (A-B-C), based on differences in variables obtained from PG-SGA.

Location

Uppsala, Sweden.

Summary of Results:

Key Findings

Inter-observer agreement

  • The dietitian emphasized loss of subcutaneous fat and muscle wastage more than the physician
  • 90% agreement in classification into SGA- A,B or C classes between physician and dietitian
  • 61% agreement for loss of subcutaneous fat and 53% agreement for muscle-wasting between physician and dietitian.

SGA class and tumor type

  • 91% with UR tumors classified in SGA -A; 48% with GI tumors classified in SGA- A (P<0.0001)
  • 33% with UR tumors reported weight loss over the past year (mean, -6.2% of body weight); 80% with GI tumors reported weight loss over the past year (mean, -9.8% of body weight) (P<0.0001).

SGA and Nutritional Parameters

  A B C
Serum Albumin (g/L)*
39.9±4.8
(26.0-48.0)
37.0±4.4
(29.0-45.0)
37.2±5.7
(31-47)
Pre-Albumin (g/L)*
0.25±0.06
(0.11-0.37
0.18±0.07
(0.08-0.35)
0.22±0.07
0.08-0.29)
6-Months Weight* Loss (%)
4.5±2.6
(1.2-9.3)
7.5±5.3
(1.5-16.7)
11.2±5.1
(5.0-22.0)

*Significant difference between Groups A and B (P<0.05)
**Significant difference between Groups A and B, C (P<0.01).

Patient Responses

  • Patients reporting altered intake over the past month had lower serum albumin than those with unaltered intake (P<0.05)
  • No significant differences in serum albumin or pre-albumin in patients reporting normal and reduced functional capacity
  • Problems with eating and reduced functional capacity were more frequent in patients with GI cancer than UR cancer (P<0.0002 and P<0.0005, respectively).

Relationships Between Components of PG-SGA and SGA Classification

  • All components were related to SGA class (P<0.05 or less)
  • PG-SGA items regarding weight loss after six months, food intake, problems keeping patients from eating, physical activity and muscle wasting all significantly contributed to predicting SGA in Groups A vs. B and C (P<0.05 or less).

Survival

  • There was a difference in survival between SGA Group A and SGA Groups B and C (P<0.001); no significant difference between SGA Groups B and C
  • Median survival for Groups B and C was nine months
  • There was a difference in survival between patients with GI tumors and metastatic GI cancer in SGA Group A and SGA Groups B and C (P<0.001 and P<0.05, respectively).
Author Conclusion:
  • The PG-SGA can be useful in the assessment of nutritional status in oncology patients
  • Patients do not seem to have difficulty understanding or answering the questions
  • Inter-observer agreement was high and dietitians, nurses and physicians should find it a useful tool
  • There was concordance between nutritional status, as assessed by the PG-SGA and serum markers (serum albumin, pre-albumin)
  • Self-reported weight loss was significantly related to serum albumin and pre-albumin
  • The PG-SGA contributed to prognostic information.
Funding Source:
Reviewer Comments:
  • Would have been nice to know how physicians and dietitians were trained to use the instrument
  • Subjects taken consecutively: No randomization was built-in, making it difficult to assess generalizability
  • Not clear when lab parameters were taken in conjunction with the assessment; this was not clearly stated.
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? N/A
  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? No
  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? 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? 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? 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? No
  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? Yes
  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? 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? 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)? 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