EAL

NCBS: Weight Loss and Weight Regain Expected After Procedure (2009)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To describe the weight loss and health improvements in a series of morbidly obese patients who underwent a laparoscopic adjustable gastric banding procedure in Taiwan.

Inclusion Criteria:

Standard National Institutes of Health (NIH) guidelines
Adults older than 18 years
BMI of greater than 35kg per m² with co-morbidities
No alcohol abuse
Free from psychiatric illnesses
Approval of human ethics committee procedures.

Exclusion Criteria:

Patients who were outside the parameters established by the NIH guidelines, as previously stated in the inclusion criteria.

Description of Study Protocol:

Recruitment: Patients in a private Taiwanese hospital. The patients were cared for in a comprehensive multi-disciplinary bariatric program.
Design: Prospective, case series of morbidly obese patients
Blinding used: None
Intervention: Laparoscopic adjustable gastric banding (LAGB) surgery
Statistical analysis: Descriptive statistics that include percentages, means, ranges and frequency counts.

Data Collection Summary:

Timing of measurements: Baseline, three, six, nine and 12 months; two and three years post-surgery
Dependent variables:
- Variable 1: Weight loss, BMI
- Variable 2: Health data (hypertension, hyperglycemia, hyperlipidemia, hyperuricemia)
- Variable 3: Patient assessment of surgical satisfaction.
Independent variables: LAGB surgery.

Description of Actual Data Sample:

Initial N: 91 patients (47 males, 44 females)
Attrition (final N): 100% follow-up rate
Mean age: 31.2 years (range 18 to 56 years)
Ethnicity: Taiwanese citizens
Other relevant demographics: 80 out of 91 patients suffered from obesity-related co-morbidities
Anthropometrics: Mean BMI of 42.7kg per m² pre-surgery (range 35 to 62.7kg per m²)
Location: Department of Surgery, Taoyuan, Taiwan and Taipei, Taiwan.

Summary of Results:

Weight Loss

Weight loss was prompt and successful after the surgery
Mean pre-operative BMI was 42.7kg per m², but declined to 33.9kg per m² three years post-surgery
Mean body weight decreased from 120.8kg to 94.7kg, after three years.

Complication Rate

All the co-morbidities related to obesity, were eliminated after two years with the exception of high blood pressure
In this experiment, the major complication rate was 0% and the minor complication rate was 3.3%
The only early complication in this study was transient esophageal stenosis due to the band being too small for the patients
There were no serious complications and only one patient had to have the band removed due to intractable vomiting.

Patient Satisfaction

Most patients were pleased and expressed an excellent, good or acceptable rating post-surgery (up to two years post-surgery)
A few patients expressed a bad or poor outcome after three months and this number did increase to six "bad" ratings after one and two years.

Author Conclusion:

This surgery is safe and acceptable for morbidly obese patients
Special consideration may be needed for the Asian population. The surgery may be justified at a lower BMI for Asian adults, because of smaller body sizes compared to US adults. Asian adults tend to have a high percentage of body fat compared to Caucasians.
Similarly, the morbidity and mortality data are expressed at lower BMIs and smaller waist sizes which would further justify the surgery prior to the standard NIH parameters.

Funding Source:

Government:

Dept. of Agriculture Western Australia

Reviewer Comments:

This article is well-written and easy to follow
The 100% follow-up data is impressive.

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?	N/A
	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?		N/A
	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?	N/A
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	N/A
	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?	Yes
	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?		No
	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.)	N/A
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	No
	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)?	Yes
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	N/A
	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?	No
	10.2.	Was the study free from apparent conflict of interest?	Yes