EAL

COPD: Effectiveness of Therapies (2007-2008)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To study the effect of nutritional drink supplements, differing in portion size and energy content, on weight gain and body composition.

Inclusion Criteria:

Considered eligible for nutrition support
Met criteria for COPD according to American Thoracic Society
BMI < 21 kg/m²
FFM index < 16 (men) and 15 (women)
BMI < 25 and weight loss > 5% in 1 month or > 10% in 6 months prior to admission to the pulmonary rehab centre

Exclusion Criteria:

Prescribed fewer than 3 cartons of nutritional supplements per day
Received pharmacological interventions to enhance body composition
Concurrent diseases such as malignancies, gastrointestinal or kidney abnormalities, metabolic or endocrine diseases and inflammatory diseases

Description of Study Protocol:

Recruitment

Consecutively admitted to an 8-week inpatient pulmonary rehab center during the periods 1995 - 1997 and 2000 - 2002 if they met inclusion/exclusion criteria.

Design:

Nonrandomized Clinical Trial with historical controls. Patients were participating in an 8 week pulmonary rehab programme and eligible for nutritional support.

Blinding used (if applicable): not applicable

Intervention (if applicable)

Group A received 3 portions of 125 ml (2380 kJ) whereas Group B received 3 portions of 200 ml (3350 kJ) daily for 8 weeks
Macronutrient composition of regimens was similar (20% protein, 60% carbohydrates and 20% fat)
Rehab program consisting of endurance and strength exercise training

Statistical Analysis

Differences between groups at baseline were tested using Student's t test for independent samples. Changes within groups between baseline and 8 weeks were tested using Student's paired t test. Changes in body composition were compared between groups using linear regression with baseline value, age, gender and assigned intervention group as predictors. The percentage of non-responders between groups was compared using the chi-square test. Weight gain was compared with expected weight as predicted by a computer simulation model.

Data Collection Summary:

Timing of Measurements

At baseline and after 8 weeks of intervention, FEV1, body composition, REE, exercise capacity and health status were determined. Body composition determined at 2, 4 and 6 weeks.

Dependent Variables

Lung function: FEV1 assessed from flow-volume curve using spirometer
Body weight, height, BMI
Body composition by bioelectrical impedance analysis
Fat free mass calculated using disease specific equations
Habitual dietary intake by dietary history
Resting energy expenditure by indirect calorimetry with ventilated hood
Exercise capacity measured using incremental bicycle ergometry test
Disease-specific health status measured by St. George's Respiratory Questionnaire

Independent Variables

Group A received 3 portions of 125 ml (2380 kJ) whereas Group B received 3 portions of 200 ml (3350 kJ) daily for 8 weeks
Macronutrient composition of regimens was similar (20% protein, 60% carbohydrates and 20% fat)
Rehab program consisting of endurance and strength exercise training

Control Variables

Gender
Age
Height
Body composition
Dietary intake

Description of Actual Data Sample:

Initial N: 39 patients with stable COPD, 19 admitted in 2000-2002 (14 males, 5 females), 20 admitted in 1995-1997 (16 males, 4 females)

Attrition (final N): as above

Age: mean age Group A: 62.0 +/- 11.1 years, Group B: 63.5 +/- 8.0 years

Ethnicity: not mentioned

Other relevant demographics: see Results

Anthropometrics: groups were matched in terms of age, gender, and oral corticosteroid use. At baseline, groups did not differ significantly in terms of age, gender, lung function, body composition, and energy balance but groups did differ in terms of the St. George's Respiratory Questionnaire (P = 0.030).

Location: The Netherlands

Summary of Results:

	Group A	Group B	P value
Weight gain (kg)	3.3 +/- 1.9	2.0 +/- 1.2	0.019
Fat free mass (kg)	2.2 +/- 2.0	1.4 +/- 1.9	NS
Fat mass gain (kg)	1.1 +/- 1.3	0.6 +/- 1.6	NS
Non-response (%)	10.5	20.0	NS
SGRQ - Symptom (pts)	-9.9 +/- 16.9	-15.8 +/- 12.9	NS
SGRQ - Activity (pts)	-7.0 +/- 15.2	4.1 +/- 20.8	NS
SGRQ - Impact (pts)	-2.7 +/- 13.4	-0.0 +/- 13.9	NS
SGRQ - Total (pts)	-5.4 +/- 10.7	-1.4 +/- 13.0	NS

Other Findings

Both groups showed a significant gain in weight (both P < 0.001) and fat free mass (Group A, P < 0.001, group B, P = 0.004).

Fat mass was significantly increased in Group A (P = 0.002) but not Group B.

Although patients in both groups significantly increased in weight, the increase was higher in Group A (3.3 +/- 1.9 kg versus 2.0 +/- 1.2 kg, P = 0.019) than Group B while receiving less energy.

The observed weight gain in group A was similar to that expected, but in Group B it was lower than expected (P < 0.001).

In both groups, fat free mass and fat mass were gained in a ratio of 2:1, fat free mass increasing primarily during the first 4 weeks.

There were no significant differences in change in health status or in functional response between groups.

Author Conclusion:

In the present study, we show that simply decreasing the portion size of nutritional drink supplements from 200 to 125 ml is a useful strategy to increase the efficacy of supplemental nutrition in terms of weight gain in depleted patients with COPD. This study illustrates that there might be an optimum for the portion size of nutritional drink supplements in chronic obstructive pulmonary disease and that more is not always better.

Funding Source:

Reviewer Comments:

Group A studied in 2000 - 2002 and Group B studied in 1995 - 1997. Groups had statistically significant differences at baseline. Authors note that they did not measure the change in daily dietary intake.

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?	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)	???
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	No
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	No
	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?	No
	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?		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?	Yes
	6.6.	Were extra or unplanned treatments described?	Yes
	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?		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