COPD: Effectiveness of Therapies (2007-2008)
- COPD diagnosis by FEV1 < 80%
- age over 35 years
- under 35 years old
- on vitamin supplementation of > 4 weeks
- with systemic disease
- FEV1 < 80% with reversibility > 15%
- in acute exacerbation
Recruitment
Methods not mentioned.
Design
Randomized controlled trial.
Blinding used (if applicable)
Double blind.
Intervention (if applicable)
15 subjects randomly assigned to receive exogenous vitamin E (400 IU per day) supplementation for 12 weeks or continue on standard supportive treatment.
Statistical Analysis
Statistical analyses included t tests and Pearson's coefficient correlations.
Timing of Measurements
Baseline and after 12 weeks supplementation.
Dependent Variables
- MDA level estimations by thiobarbituric acid (TBA) reaction and spectrophotometer (Asakawa and Matsushita, 1980)
- alpha tocopherol levels by fluorometer units vs concentration of tocopherol standards (Hansen and Warwick 1969)
- erythrocyte superoxide dismutase (SOD) levels estimate on baisi of inhibition of pyrogallol autoxidation by SOD (Markland and Markland, 1974 and Nandi and Chatterji 1988)
- forced expiratory volume in first second (FEV1)
- FEV1/FVC
- peak expiratory flow rate (PEFR)
Independent Variables
- Assigned to receive exogenous vitamin E (400 IU per day) supplementation for 12 weeks or continue on standard supportive treatment
Control Variables
none
Initial N: 30 included in the study, 24 male, 6 female, 20 nonsmoking controls matched for age and sex
Attrition (final N):
- patients n = 30
- controls n = 20
Age: over 35 years
Ethnicity: not clear
Other relevant demographics: 80% of patients were male
Anthropometrics: controls were age and sex matched
Location: New Delhi, India
Other Findings
Mean MDA level in patients was 29.7% higher than controls at baseline (5.91 + 1.23 nmol/ml vs 4.55 + 1.57 nmol/ml, p=0.001).
Mean plasma alpha-tocopherol level in patients (7.09 + 2.14 micrograms per ml)was 28.67% lower than controls (9.94 + 2.01 micrograms per ml, p < 0.001).
Mean SOD level in patients was 30.9% lower than controls (1692 + 259 units/gm Hb vs 2451 + 131 units/gHb, p<0.001). At baseline, smokers with COPD had higher MDA levels but lower antioidant (SOD and tocopherol ) levels than healthy controls.
Twelve weeks of vitamin E supplementation produced 42.8% reduction in mean MDA level (3.37 + 0.81 nmaol/ml vs 5.91 + 1.43 nmol/ml, p <0/001) No significant change in mean plasma alpha-tocopherol levels and mean SOD level was observed after 12 weks of vitamin E supplementation.
No significant improvement in FEV1, FEV1/FVC and PEFR was observed after 12 weeks of vitamin E supplementation.
University/Hospital: | Maulana Azad Medical College |
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? | ??? | |
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? | ??? | |
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) | Yes | |
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? | 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? | 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.) | 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? | 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? | ??? | |
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? | ??? | |
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? | ??? | |
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? | 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? | No | |
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? | No | |
10. | Is bias due to study's funding or sponsorship unlikely? | ??? | |
10.1. | Were sources of funding and investigators' affiliations described? | No | |
10.2. | Was the study free from apparent conflict of interest? | ??? | |