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:

The purpose of this study was to assess all complications linked to two types of adjustable gastric bands.

Inclusion Criteria:

The only inclusion criteria mentioned was the study date: July 1994 to August 1998
Operations included adjustable silicone gastric bands (ASGB) and Swedish adjustable gastric bands (SAGB) in Salzburg, Austria and Hallein, Austria
All the patients in this study were from a personal series of patients by the two study authors (Miller and Hell).

Exclusion Criteria:

None mentioned.

Description of Study Protocol:

Recruitment: Morbidly obese, surgical patients of study authors in Salzbur, Austria and Hallein, Austria
Design: Prospective, four-year follow-up case series
Blinding used: Not applicable
Intervention: Two surgical procedures (ASGB and the SAGB)
Statistical analysis: Means, ranges, and frequency counts.

Data Collection Summary:

Timing of measurements: Baseline, 12, 24 and 36 months
Dependent variables: Variable 1: Weight loss post-surgery; Variable 2: Early and late complications
Independent variables: Surgical intervention of laparoscopic adjustable gastric banding procedures (either the SAGB or the SAGB).

Description of Actual Data Sample:

Initial N: 158 (102 ASGB and 54 SAGB)
Gender: ASGB surgery: 84 females, eight males; SAGB surgery: 48 females, six males
Attrition (final N): 98% follow-up rate
Age: Mean age was 35 to 38 years depending on surgical category with a range of 17 to 72 years for both procedures
Ethnicity: European adults from Austria
Other relevant demographics: Surgical dates of procedures July 1994 to August 1998
Anthropometrics: Average pre-operative BMI for SAGB was 43kg per m² with a range of 37 to 68kg per m²; Average pre-operative BMI for ASGB was 45kg per m² with a range of 38 to 65kg per m²
Location: Salzburg, Austria and Hallein, Austria.

Summary of Results:

Weight Loss

The range of pre-operative weights varied from 89 to 320kg
The mean BMI for the patients undergoing the SAGB procedure was 43kg per m² with a range of 37 to 68kg per m² and the mean BMI for the patients undergoing the ASGB procedure was 45kg per m² with a range of 38 to 65kg per m²
The post-operative weight loss was nearly identical for both procedures.

Complications

Early post-operative complications that required an operation were one wound hematoma and one wound infection of the port site
Some of the late complications that required re-operations included two pouch dilatations, three band leakages, one band migration one late port infection and one esophageal dysmotility disorder
No deaths were reported from these procedures
The complication rate was approximately evenly split between the two procedures; six from the SAGB surgery and seven from the ASGB surgery.

Author Conclusion:

Adjustable gastric banding procedures meet the criteria a low-risk laparoscopic procedure for the treatment of morbid obesity
The surgical risks are very low and the complications seem to be minimal, treatable and safe.

Funding Source:

University/Hospital:

Landeskran Kenanstalten, A.O. KH-Hallein, Ludwig Boltzmann Institute for Experimentelle und Chirurgische Forschung Hallein Austria

Reviewer Comments:

A neutral rating was given due to low scores on certain sections of the quality rating checklist
Overall, I was disappointed to see the minimal comparison of the two procedures. I believe a stronger presentation could have been made to directly compare the post-surgical outcomes for the two groups of patients.

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?	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?	???
	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?	???
	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?		N/A
	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.)	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?		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?	N/A
	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?	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)?	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?	No
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