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 investigate quality of life, presence of co-morbidities, body mass index (BMI) and medication use following laparoscopic adjustable gastric banding in patients 60 years of age and older.

Inclusion Criteria:

Patients who underwent a laparoscopic adjustable gastric banding between February 2000 and September 2005 were eligible for participation if the following criteria were met:
- Aged 60 years or older
- Body mass index (BMI) greater than 40kg per m² or greater than 33kg per m² with obesity-related co-morbidities.

Exclusion Criteria:

At risk for unacceptable peri-operative risk
History of malignancy five years prior to study
Suffered from poorly controlled psychiatric illness
Drug or alcohol addiction
Unwilling to participate in program of post-surgery follow-up.

Description of Study Protocol:

Design: Prior to laparoscopic adjustable gastric banding (LAGB), all patients completed pre-operative quality of life assessment. Patients underwent LAGB by one surgeon. Following surgery, patients were encouraged to attend post-operative review every eight weeks following surgery to measure weight loss and post-surgical complications.
Statistical analysis: Not described.

Data Collection Summary:

Timing of Measurements

Patients were encouraged to attend post-surgery follow-up sessions every eight weeks to measure for weight loss, quality of life and complications.

Dependent Variables

Weight loss was measured using scale, described as percent excess weight lost (% EWL using ideal mid-frame weight from Metropolitan Life Tables)
Complications
Co-morbidity improvement
Quality of life.

Independent Variables

All patients underwent LAGB between February 2000 and September 2005.

Control Variables

Prior to surgery, all patients completed a detailed pre-operative quality of life assessment (Medical Outcomes Study Short Form-36)
Following surgery, all patients completed a post-operative questionnaire packet consisting of post-operative Medical Outcomes Study Short Form-36 (scores compared to age-matched general Australian population), purpose-designed co-morbidity and medication survey, and weight loss.

Description of Actual Data Sample:

Initial N: 40 (32 females, 8 males)
Attrition (final N): 35 (two were uncontactable/changed address, two were unwilling to continue follow-up, one died of breast cancer)
Age: Mean age 65.8 years (range 60 to 72 years)
Ethnicity: Not described
Anthropometrics: Mean BMI was 42.2kg per m²(range 33-54kg per m²)
Location: Queensland, Australia (John Flynn Hospital).

Summary of Results:

Body Weight

Mean change in BMI was -9.3kg per m² (range -1.8 to -13.4kg per m²) at 48 months post-surgery
Mean change in body weight was from 119kg to 92.7kg
Percent excess weight loss (%EWL) was 54% at two years post-surgery.

Complications

No peri-operative complications
Three late complications occurred (7.5%) due to band slippage and access-port infections
One band was removed due to patient's request
No in-hospital deaths
One patient died 18 months post-surgery from breast cancer.

Co-morbidity Improvement

Between 44-90% of all patients reported improvements (either better or much better) in obesity-related co-morbidities.

Quality of Life

86% of patients rated their health-in-general as much better following LAGB.

Author Conclusion:

The author concludes that LAGB in patients 60 years and older results in safe, achievable weight loss, improves related co-morbidities and improves quality of life. However, improvement in BMI and medication use may be more modest in younger patients undergoing LAGB than in patients 60 years and older.

Funding Source:

University/Hospital:

John Flynn Hospital (Queensland Australia)

Reviewer Comments:

The author did not describe statistical analyses methods.

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?		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.)	???
	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?	Yes
	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.)	No
	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?	Yes
	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?		No
	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?	???
	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?	No
	7.5.	Was the measurement of effect at an appropriate level of precision?	No
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	No
	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?		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?	No
	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)?	No
	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?	No
	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?	No
	10.2.	Was the study free from apparent conflict of interest?	Yes