EAL

MNT: RDN in Medical Team (2015)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To review weight loss findings and health benefits in terms of improvement or resolution of comorbid illnesses and improvements in quality of life (QoL) in a cohort of patients with greater than six-month follow-up after placement of the Swedish Adjustable Gastric Band (SAGB).

Inclusion Criteria:

Underwent laparoscopic adjustable gastric banding (LABG) between January 2011 and July 2007
Qualified for surgery according to standards defined by the 1991 NIH Consensus Conference Statement of Gastrointestinal Surgery for Severe Obesity.

Exclusion Criteria:

Did not undergo laparoscopic adjustable gastric banding (LABG) between January 2011 and July 2007.

Description of Study Protocol:

Recruitment
Recruited from physicians' offices.

Design

Data was collected prospectively for 838 consecutive morbidly obese patients who underweight LAGB between January 2001 and July 2007
Patients were followed by a multi-disciplinary team consisting of a surgeon, physician, dietitian and exercise consultant, all of whom were involved in the process of data collection and evaluation of outcomes
Follow-up included monthly visits with a member of the multi-disciplinary team for the first six months, at approximately nine months and 12 months and then biannually or as required
Comorbidity and and QoL data after weight loss with gastric banding was collected and evaluated.

Blinding Used
None.

Intervention
Swedish adjustable gastric band placement.

Statistical Analysis

Two-sided student's T-test was used to test significant differences between two samples of quantitative variables
Analysis of variance (ANOVA) was used to test for differences in more than two groups
Leven's test to determine homogeneity of variance between groups
P<0.05 was considered statistically significant.

Data Collection Summary:

Timing of Measurements

Fasting blood sugar levels, HbA1c and lipid concentrations were collected pre-operatively and follow-up values were obtained from the patient's treating endocrinologist or primary care physician or as part of the routine laboratory measurements performed at the clinic
Number, dose and frequency of all hypoglycemic and insulin requirements, anti-hypertensive, lipid-lowering, asthma, analgesics, anti-reflux and anti-depressant medications pre-operatively and post-operatively assessed at each follow-up visit in all patients with greater than six months of follow-up
Improvement and resolution of comorbid illness identified by dose reduction in medication with improvement in specific laboratory values and evaluated throughout the study
Weight evaluated at each follow-up time-point using the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) and Beck Depression Inventory II (BDI-II)
Quality of life perception and depressive mood were identified at baseline and during follow-up visits.

Dependent Variables

Improvement in comorbid conditions
Resolution of comorbid conditions
Weight change
BMI
Percentage of excess weight loss (EWL)
Quality of life
Depressive mood.

Independent Variables

Gastric banding using the Swedish Adjustable Gastric Band (SABG).

Control Variables

Age
Gender
Height.

Description of Actual Data Sample:

Initial N
838 patients (159 males, 679 females).

Attrition (Final N)
175 patients matured to 36-month follow-up.

Age
44±8 years.

Ethnicity

White: 97.1%
Indian/Chinese: 1.4%
Aboriginal: 0.2%
Hispanic: 1.0%
Pacific Island/Maori: 0.2%.

Other Relevant Demographics
None.

Anthropometrics
Baseline

Height: 168±9cm
Absolute weight: 122±25kg
Ideal body weight: 63±7kg
Excess body weight: 60±39kg
BMI: 44±8 kg/m².

Location
Australia.

Summary of Results:

Key Findings

In the total consecutive group of patients, BMI decreased from 44±8kg/m² to 32±7kg/m² at 24 months and 32.7±7kg/m² at 36 months (P<0.001). Percentage EWL in the same intervals was 52±16% (P<0.001) and 54±23% (P<0.001).
For the entire cohort of 545 patients with comorbid illnesses, after a median follow-up of 13 months, precentage EWL was 26±17%, with a change in BMI of 5.0kg/m² and an absolute weight loss of 15±8kg
Of the 545 patients with comorbid illnesses under current review, weight loss was associated with comorbid illness improvement or resolution relative to baseline in all illnesses studied
Pre-operatively, QoL scores in the eight domains were significantly lower in comparison with community norms, but after a median follow-up of 13 months, all eight domain scores increased significantly to within the range of QoL of individuals in the normal community
Pre-operatively, 342 patients completed the BDI-II with a mean score of 17.3±10, indicating mild to moderate levels of depressive mood. After surgery, these patients experienced a significant fall in their BDI-II depression scores to a score within the normal range of 7.2±6 (P<0.001).

Weight Loss

Variables	Six Months N=506	12 Months N=461	24 Months N=291	36 Months N=175
Absolute Weight, kg	103±20	94±19	90±16	90±19
BMI, kg/m²	37±7	33±6	32±5	32±7
Percentage EWL	32±4*	47±15*	52±16*	54±23*

* P<0.001.

Resolution or improvement of Comorbidities at a Median Follow-Up of 13 Months
Range, six months to 36 months

Comorbidity	Percentage Resolution or Improvement
T2DM	79%
IGT/insulin Resistance	69%
Metabolic Syndrome	78%
Hypertension	67%
Dyslipidemia	66%
GERD	69%
Asthma	57%
Arthritis/Joint Pain	70%
PCOS	48%
Depression	57%

Author Conclusion:

LAGB using the SAGB is an effective method for achieving and maintaining substantial weight loss in the majority of morbidly obese patients undergoing bariatric surgery
After gastric banding, morbidly obese patients experienced marked weight loss in addition to a reduction of the major comorbid conditions that not only threaten their lives but significantly impair their daily QoL.

Funding Source:

Industry:

Ethicon Endo-Surgery

Other:

Reviewer Comments:

Study limitation may include attrition rate with 21% of patients at the 36-month follow-up point with no description for cause of attrition.

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)	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?	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?	???
	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?	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?	Yes
	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?	N/A
	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?		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?	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?	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)?	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?	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?		No
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes