COPD: Effectiveness of Therapies (2007-2008)
- Patients acutely admitted to hospital for exacerbation of COPD
- COPD diagnosis based on GOLD criteria
- Criteria for hospitalization were recent increase in breathlessness, cough and sputum production of sufficient severity to warrant hospital admission judged by an independent chest physician
- Nutritional intervention criteria were a BMI < 22 or BMI < 25 and >5% weight loss in 1 month, or >10% weight loss in 6 months prior to admission
- Diabetes type 1
- Thyroid or intestinal diseases
- Carcinoma
Recruitment
Methods not described.
Design: Randomized Controlled Trial, 2-center
Blinding used (if applicable): Double blind
Intervention (if applicable)
- 3 x 125 ml (2.38 MJ/day, 20% protein, 20% fat, 60% carbohydrate) nutritional supplementation
- Placebo group received similar amounts of noncaloric fluid
- Medical therapy (bronchodilator therapy and systemic glucocorticoids) and dietetic consultation were standardized but slightly different between 2 centers and dietary intake measured daily
Statistical Analysis
Differences in baseline characteristics between groups of 2 hospitals compared using Student's t test for independent samples. For comparisons between intervention and control groups, ANOVA was used with day 8 values.
Timing of Measurements
Measurements completed upon admission and on days 4 and 8 of hospitalization. Dietary intake and body weight assessed daily.
Dependent Variables
- Body composition measured with bioelectrical impedance analysis
- Respiratory muscle strength assessed by measuring maximal inspiratory mouth pressure
- Quadriceps strength measured through dynamometer
- Handgrip strength measured through handgrip dynamometer
- Lung function: FEV1 and inspiratory vital capacity calculated from flow volume curve
- Symptoms including dyspnea at rest and while eating, loss of appetite, early satiety, bloating, and fatigue measured with visual analog scale
- Body weight, height
- Arterial blood gases
Independent Variables
- Disease severity
- 3 x 125 ml (2.38 MJ/day) nutritional supplementation
- Placebo group received similar amounts of noncaloric fluid
- Medical therapy and dietetic consultation were standardized and dietary intake measured daily
Control Variables
Initial N: 56 patients randomized
Attrition (final N): 47 completed the study, 23 in intervention (14 males, 9 females), 24 in placebo (18 males, 6 females). Dropouts caused by medical problems (n = 4), alcohol withdrawal delirium (n = 1), and nausea after supplementation (n = 4).
Age: mean age intervention group: 66 +/- 8 years, placebo group: 65 +/- 10 years
Ethnicity: not mentioned
Other relevant demographics:
Anthropometrics: No significant differences in BMI or FFMI between centers or groups at baseline.
Location: The Netherlands
Intervention |
Placebo |
|
Weight (kg) | 1.37 +/- 1.3, P < 0.05 | 1.12 +/- 1.2, P < 0.05 |
Fat free mass (kg) |
-0.5 +/- 2.6 |
-0.4 +/- 2.7 |
Fat mass (kg) | 1.7 +/- 2.5, P < 0.05 | 1.5 +/- 2.5, P < 0.05 |
FEV1 (% predicted) | 5 +/- 6, P < 0.05 | 5 +/- 9, P < 0.05 |
IVC (% predicted) | 7 +/- 12, P < 0.05 | 10 +/- 17, P < 0.05 |
Pi-max (cmH2O) | 3 +/- 10 | 3 +/- 13 |
Mean handgrip strength (kg) | 0 +/- 3 | 0 +/- 3 |
Quadriceps strength (Nm) |
3 +/- 8 | 2 +/- 9 |
Score of dyspnea at rest | -3.8 +/- 2.5, P < 0.05 | -4.3 +/- 3.2, P < 0.05 |
Score of dyspnea while eating | -4.2 +/- 2.5, P < 0.05 | -4.7 +/- 3.3, P < 0.05 |
Score of loss of appetite | -2.7 +/- 3.2, P < 0.05 | -2.6 +/- 2.9, P < 0.05 |
Score of early satiety | -3.2 +/- 3.3, P < 0.05 | -2.5 +/- 3.3, P < 0.05 |
Score of bloating | -2.4 +/- 3.4, P < 0.05 | -3.0 +/- 2.8, P < 0.05 |
Score of fatigue |
-4.2 +/- 3.7, P < 0.05 |
-3.9 +/- 3.5, P < 0.05 |
Other Findings
47% of patients had experienced recent involuntary weight loss prior to admission.
Degree of weight loss was inversely related to resting arterial oxygen tension (r = 0.31, P < 0.05).
Nutritional intervention resulted in a significant increase in energy (16% vs placebo) and protein intake (38% vs placebo).
Over the period of hospitalization the mean energy intake in the intervention group was significantly higher compared to the placebo group (10.89 +/- 2.01 vs 9.40 +/- 2.54 MJ/day, P < 0.05).
Mean energy intake was 194 +/- 50 KJ/kg body weight compared to 159 +/- 42 kJ/kg body weight (P = 0.022).
Mean protein intake was 1.8 +/- 0.4 g/kg body weight vs 1.3 +/- 0.3 g/kg body weight (P < 0.01).
Mean duration of hospitalization was 9 +/- 2 days.
Relative to usual care, no additional improvements in lung function or muscle strength were seen after nutritional intervention.
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? | 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? | 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? | Yes | |
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) | Yes | |
3.2. | Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? | Yes | |
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? | ??? | |
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? | ??? | |
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? | ??? | |
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? | ??? | |
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? | N/A | |
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? | 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? | Yes | |
10.1. | Were sources of funding and investigators' affiliations described? | Yes | |
10.2. | Was the study free from apparent conflict of interest? | Yes | |