ONC: Dietary Supplements and Medical Food Supplements Containing Fish Oil (2013)
To examine the effect of dietary compliance post-hoc on intake and body composition in patients with unresectable pancreatic cancer
1. Weight loss of greater than 5% in the previous 6 months
2. Life expectancy of greater than 2 months
3. Karnofsky performance score of 60 or more
1. Chemotherapy
2. Radiotherapy
3. Surgical treatment in the previous month
4. Consumption of fish oil capsules
5. Medications such as steroids that could affect metabolism
Recruitment Post-hoc anaylsis of 200 hundred patients with unresectable adenocarcinomas of the pancreas
Design Patients were asked to consume 2 cans per day of either a protein and energy dense n-3 fatty acid oral nutritional supplement or an isocaloric, isonitrogenous control supplement without n-3 fatty acids for 8 weeks
Each can contains 1.1g EPA, 310 Kcal, 16g Protein
Statistical Analysis
1. Intent to treat analysis
2. Repeated measures regression models were used to consider the effects of compliance with 1.5 cans of either supplement on a series of nutritional outcomes - energy & protein intake, weight, lean body mass and quality of life
3. Generalized estimating equations were used to permit the inclusion of data from patients with incomplete data records
5. P<0.05 level statistical significance (two tailed)
Timing of Measurements
Baseline, 4 weeks and 8 weeks
•Dietary intake assessed by food diary completed over 3 consecutive days including 2 weekdays plus one weekend day
•Weight
•Lean Body Mass
•Quality of Life
Dependent variables
•Total protein intake (g/day) determined by 3 day food diary plus daily record of number of supplement cans consumed
•Total energy intake (kcal/day) determined by 3 day food diary plus daily record of number of supplement cans consumed
•Weight (kg) measured to the nearest 0.1 kg using a spring balance scale
•Lean body mass measured by an Xitron multifrequency bioelectrical impedance analyzer
•Quality of life measured by the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire
Independent variables
•Intake of protein and energy dense oral nutrition supplement +/- n-3 fatty acids
Control variables
•Weekly contact with experienced clinician by either face to face interview or telephone contact for 8 weeks
•Dietary assistance
•Patients encouraged to view supplement as essential component of their treatment
Initial N: 200 patients (n = 95 oral supplement with n-3 fatty acids) (n = 105 oral supplement without n-3 fatty acids)
Attrition (final N):
•Baseline n=185
•4 weeks n=148
•8 weeks n=110
Age:
•Compliant 66.8 +/- 1.0 y.o
•Noncompliant 68.3 +/-1.1 y.o
Ethnicity: None indicated although study was an international multi-centered study
Other relevant demographics:
•The a priori definition of dietary compliance was average consumption over a week period of at least 1.5 cans of either oral nutritional supplement per day
Anthropometrics
Over 8 week period
Compliant | Noncompliant | |
Body Weight | 0.5kg increase | 0.7kg decrease |
Lean Body Mass | no change | no change |
Plasma EPA Levels | 2.7% | 1.6% |
Location: International, multi-centered
Averages over 8 weeks
Variables |
Compliant Group |
Noncompliant Group | Statistical Significance |
Total energy intake (kcal/day | 1845 | 1344 | <0.001 |
Total protein intake (g/day) | 77.0 | 51.6 | <0.001 |
Weight (kg) | 61.8 | 60.0 | <0.001 |
Lean body mass | 44.1 | 43.6 | 0.556 |
Quality of Life | 56.8 | 52.4 | 0.075 |
Other Findings
•Supplement intake does not inhibit food intake
•Plasma phospholipid EPA
- Baseline: p=0.939
- Week 4: p<0.0001
- Week 8: p=0.002
University/Hospital: | Universität Erlangen-Nürnberg (Germany) |
Limitations:
•3 day food diary may not have been an accurate representation of patient's habitual dietary intake
•Clinically important differences in baseline quality of life between the compliant and noncompliant groups
•Large drop out rate - no reasons given
•Posthoc analysis should be viewed with considerable skepticism.
•Severe pain, nausea and vomiting (all symptoms common in unresectable pancreatic cancer patients),which could affect results not reported
Quality Criteria Checklist: Primary Research
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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? | 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? | ??? | |
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) | No | |
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.) | Yes | |
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? | No | |
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%.) | No | |
4.3. | Were all enrolled subjects/patients (in the original sample) accounted for? | No | |
4.4. | Were reasons for withdrawals similar across groups? | ??? | |
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? | Yes | |
5.1. | In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? | Yes | |
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? | 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? | Yes | |
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? | Yes | |
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 | |