MNT: RDN in Medical Team (2015)


Wong SKH, So WY, Yau PYP, Chan AKL, Lee S, Chan PN, Chow FCC, Chung SSC. Laparoscopic adjustable gastric banding for the treatment of morbidly obese patients: Early outcome in a Chinese cohort. Hong Kong Med J. 2005; 11: 20-29. 

PubMed ID: 15687512
Study Design:
Prospective Cohort Study
B - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
To evaluate the efficacy of laparoscopic adjustable gastric banding in the management of morbid obesity in a cohort of Chinese patients.
Inclusion Criteria:
  • Between 18 years and 55 years old
  • BMI greater than 40kg/m2 or greater than 35kg/m2 to 40kg/m2 with serious co-morbidities
  • No excessive intake of sweets or alcohol
  • No concurrent psychiatric illness.
Exclusion Criteria:
Pre-operatively screened to rule out:
  • Endocrine disorders including hypothyroidism, diabetes and Cushing's syndrome
  • Presence of hiatus hernia or other upper gastrointestinal pathology.
Description of Study Protocol:


Morbidly obese patients seeking treatment at the Chinese University of Hong Kong, Prince of Wales Hospital in Hong Kong between August 2002 and September 2003 were considered for this study. No other recruitment methods were discussed.


Cohort study of available appropriate participants. 


Usual treatment provided to all subjects included a team approach with all patients working with the dietitian, physician, psychiatrist (if necessary) and surgeon prior to surgery and as part of follow-up.

Statistical Analysis

  • Median
  • Range
  • Wilcoxon signed rank test
  • Mean
  • Standard deviation
  • Significance was P<0.05.
Data Collection Summary:

Timing of Measurements

  • Pre-operative
  • Monthly for six months
  • Every three months.

Dependent Variables

  • Weight (kg)
  • Blood pressure (mm Hg)
  • Waist circumference (cm)
  • Quality of life (Chinese version of Medical Outcome Study, 36-item short form) including physical functioning, role limitations caused by physical problems, bodily pain, social functioning, general mental health, role limitations caused by loss of vitality and general health perceptions
  • Impact on co-morbidities (obstructive sleep apnea syndrome, diabetes mellitus, hypertension, amenorrhea, degenerative joint disease).

Independent Variables

  • Age
  • Sex
  • Operative outcome.
Description of Actual Data Sample:
  • Initial N: N=10 (six males, four females)
  • Attrition (final N): Same
  • Age: From 23 years to 48 years (median 34 years)
  • Ethnicity: Chinese
  • Other relevant demographics: Co-morbidities included eight with sleep apnea, three with diabetes mellitus, two with hypertension, two with amenorrhea, two degenerative joint disease.


  • BMI: 38kg/m2  to 67kg/m2 (median 47kg/m2)
  • Weight: 115kg to 196kg (median 127kg).


Hong Kong, China.


Summary of Results:

Key Findings

  • Follow-up data available at six, 12 and 18 months:
    • Mean weight loss: 19.3kg, 22.4kg and 25.9 kg
    • Post-operative mean drop in BMI: 6.9kg/m2, 8.7kg/m2 and 10.1kg/m2
    • Mean percentage of excess body weight loss: 34.9%, 36.5% and 40.5%.
  • Mean waist circumference significantly reduced from 134.9 (SD 11.1) to 111.4 (SD 19.5), P=0.032
  • Systolic blood pressure significantly reduced from 124mm Hg (SD 8mm Hg) to 108mm Hg (SD 8.4mm Hg), P=0.020
  • Pulse pressure significantly reduced from 60mm Hg (SD 17.6mm Hg) to 31mm Hg (SD 7.8mm Hg), P=0.024.

Other Findings

  • Operative outcomes were all considered within normal limits for success
  • Three patients lost less than 20kg in the first year: One patient defaulted at three-month follow-up and two had poor dietary compliance
  • Reduced anti-hypertensive drug dosage, resolved knee pain, improved glycemic control and reduced medication, improved sleep apnea and reduced need for PAP therapy
  • Quality of life scores were generally lower than Hong Kong population based data but all showed significant improvement post-operatively.
Author Conclusion:
Laparoscopic adjustable gastric banding is an effective procedure for morbid obesity. Multi-disciplinary care is essential in obese patients. The surgeons, physicians, nutritionists and psychologists must monitor the patient during the entire weight loss program.
Funding Source:
University/Hospital: The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
Reviewer Comments:
This is a very small study focusing on the surgical procedure and efficacy. The role of the dietitian is not explicit. It appears that they were probably involved in pre-operative education to consume small frequent meals and avoid calorie-containing drinks, sweets, congee and bread. The dietitian also instructed patients on a post-operative liquid diet (four weeks), puree diet (two weeks) and then normal diet.
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? ???
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? 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")? Yes
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? Yes
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? No
  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? No
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? Yes
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)? No
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? ???
  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? Yes
  10.2. Was the study free from apparent conflict of interest? Yes