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:

Several gastric bands have been used for surgical treatments of obesity. This study was a prospective, randomized trial to evaluate the differences between different types of gastric bands [Swedish adjustable gastric band (SAGB) and Lap-Band].

Inclusion Criteria:

Patients were included in the study if:

They had a BMI greater than 40kg/m²
They had a BMI of 35 to 40 with comorbidities
Those with a BMI greater than 60 who could not undergo derivative procedures.

Exclusion Criteria:

Patients were excluded from the study if:

They had a BMI greater than 60 who were fit for "derivative procedures"
They had previous surgery on the upper abdomen
They had psychiatric illnesses that could endanger a close post-operative follow-up.

Description of Study Protocol:

Recruitment

Participants were recruited during pre-operative visits, where two surgeons described the experimental nature of the study and obtained informed consent.

Design

A randomized control trial.

Blinding Used

Patients and assessment staff were unaware of surgical device.

Intervention

Patients were recruited and screened at preoperative assessments. Prior to surgery, a medical history, body fat and skin elasticity, physical examination and BMI were assessed.

Standardized surgical techniques were used (Forsell and Kuzmak), with one of two different gastric banding used for each patient: Lap-Band and SAGB. Post-operatively, patients maintained a liquid diet for two weeks, then slowly transitioned to a regular diet. Gastric band adjustments were performed at six weeks.

Statistical Analysis

Descriptive statistics and frequency analyses were used to describe outcomes data. One-tailed T-tests were used to compare excess weight loss one and two years post-operative by treatment. Presence of complications by treatment type were compared using chi square analyses.

Data Collection Summary:

Timing of Measurements

Outpatient visits were planned for seven days, 14 days, and one, two, three, six, 12, 18 and 24 months.

Dependent Variables

Height, weight, BMI
Excess weight loss
Presence and types of complications experienced.

Independent Variables

Use of Lap-Band vs. SAGB.

Description of Actual Data Sample:

Initial N

N=400, 200 patients in each treatment
Lap-Band: 19 males (9.5%)
SAGB: 27 males (13.5%)
Eight patients had a BMI less than 30 with existing comorbidities:
- Diabetes (N=2)
- Asthma (N=1)
- Hypertension (N=3)
- Depression (N=1)
- Sleep apnea syndrome (N=2).

Attrition (final N)

Participants completing follow-up measurements

	Total	Lap-Band	SAGB
1 year	392 (98%)	192 (96%)	200 (100%)
2 years	355 (88.8%)	174 (87%)	181 (90.5%)

Age

43.6±10.2 years.

Anthropometrics

Baseline comparisons not reported.

Location

Dolan Park Hospital, Birmingham, England.

Summary of Results:

Mean±SD of Weight Data at Follow-up

Variable	1-year FU	2-year FU
BMI (kg/m²)	40.6±3.0	35.2±7.0
Excess weight loss (percentage change)	48.2%	56.0%

Patients with an estimated weight excess of 50kg or less [108 patients (27.0%)] had an excess weight loss of 55% after two years.

Those with a weight excess of greater than 50kg [292 patients (73.0%)] had an excess weight loss of 44% (T-test, P=0.004).

Other Findings

Complications experienced after the operation:

Concomitant colecystectomy
Concomitant Nissen fundoplication
Transient gastric occlusion
Ring slippage
Port defect
Colonic perforation
Pneumonia
Pulmonary embolism
Death

Author Conclusion:

No differences were seen in the outcomes or complications for the two different banding techniques. The laparoscopic adjustable gastric banding is a safe and effective treatment for extreme obesity or relative obesity with the presence of comorbidities.

Funding Source:

University/Hospital:

University of Vergata (Italy), University La Sapienza(Italy), Dolan Park Hospital (UK)

Reviewer Comments:

It is difficult to fully evaluate the data presented due to:

Lack of detail on the collection of weight data
Inconsistent comparisons of collected data across treatments
No baseline data to serve as a standard for follow-up values
Lack comparisons between groups at baseline
No data reported on the actual effectiveness by treatment type.

Without much of this data, the claims of safety and effectiveness are difficult to prove.

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?	???
	1.3.	Were the target population and setting specified?	No
2.	Was the selection of study subjects/patients free from bias?		No
	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?	No
	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?		No
	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%.)	No
	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?		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?	N/A
	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?		No
	7.1.	Were primary and secondary endpoints described and relevant to the question?	No
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	No
	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?	???
	7.5.	Was the measurement of effect at an appropriate level of precision?	???
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	No
	7.7.	Were the measurements conducted consistently across groups?	???
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		No
	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?	Yes
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	No
	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)?	???
	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?	N/A
	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?		No
	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?	Yes
	10.2.	Was the study free from apparent conflict of interest?	???