COPD: Determination of Energy Needs (2007)
Cases:
- Moderate to severe COPD, FEV1 of 37 +/- 15% predicted
Controls:
- Aged over 50 years
- Mean FEV1 of 112 +/- 16% predicted
Cases:
- Patients with increase in FEV1 of more than 10% of predicted after administration of bronchodilator
- With unstable COPD
Controls:
- No evidence of COPD based on questionnaires and lung function testing
Recruitment
Patients consecutively admitted to an inpatient pulmonary rehab centre in stable clinical condition. Controls were part of a random population sample of subjects living in same area as patients.
Design
Case-Control Study.
Blinding used (if applicable)
Not applicable.
Intervention (if applicable)
Not applicable.
Statistical Analysis
Groups compared by ANOVA or Mann-Whitney U test where appropriate. Chi-squared test used to compare categorical variables.
Timing of Measurements
Measurements made and compared between groups.
Dependent Variables
- Resting energy expenditure measured by indirect calorimetry
- Fat free mass measured by bioelectrical impedance
- Tumor necrosis factor alpha, soluble tumor necrosis receptors 55 and 75 (sTNF-R55, sTNF-R75), interleukin-6 and interleukin-8, CRP and lipopolysaccharide binding protein (LBP) were measured by ELISA
- Lung function testing included spirometry, transfer factor, thoracic gas volumes, and airway resistance
Independent Variables
- COPD or healthy
Control Variables
Initial N: 30 patients, 26 healthy controls
Attrition (final N): 30 patients, 26 controls
Age: mean age patients: 61 +/- 6 years, controls: 59 +/- 5 years
Ethnicity: not mentioned
Other relevant demographics:
Anthropometrics: Controls were age-matched but not gender matched
Location: The Netherlands
|
Patients (n=30) | Controls (n=26) |
p value |
M:F |
23:7 |
13:13 |
-- |
BMI |
23.5 +/- 4.2 |
27.0 +/- 2.5 |
<0.001 |
FFM (kg) |
47.7 +/- 2.2 |
49.5 +/- 7.6 |
NS |
Fat mass (kg) | 17.8 +/- 7.0 | 25.5 +/- 5.3 | <0.001 |
sTNF-R55 (ng/ml) | 1.4 +/- 0.8 | 1.0 +/- 0.3 | NS |
sTNF-R75 (ng/ml) | 1.7 +/- 1.0 | 1.1 +/- 0.4 | <0.05 |
IL-8 (pg/ml) | 140 +/- 230 | <20 | <0.001 |
CRP (ug/ml) | 64.3 +/- 79.9 | <5 | <0.01 |
LBP (ug/ml) | 13.2 +/- 7.7 | 8.6 +/- 3.1 | <0.001 |
Other Findings
14 patients had a normal REE and in 16 it was raised.
The mean BMI and fat mass were significantly lower in the latter but pulmonary function data were similar in the 2 groups.
BMI was significantly higher in healthy subjects.
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) | N/A | |
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) | N/A | |
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? | Yes | |
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.) | 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.) | ??? | |
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? | 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? | Yes | |
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.) | Yes | |
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? | Yes | |
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? | Yes | |
6.5. | Were co-interventions (e.g., ancillary treatments, other therapies) described? | Yes | |
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? | 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? | 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? | ??? | |
8.1. | Were statistical analyses adequately described and the results reported appropriately? | ??? | |
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)? | 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? | No | |
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 | |