MNT: Weight Management (2015)

Citation:
Singhal R, Kitchen M, Bridgwater S, Super P. Dietetic-led management of patients undergoing laparoscopic gastric banding: early results. Surgical Endoscopy, 2010; 24: 1,268-1,273. PubMed ID: 19997934
 
Study Design:
Retrospective Cohort Study
Class:
B - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
To analyze the differences in weight loss outcomes and complications during a period of two years, based on dietitan-led vs. surgeon- or nurse-specialist-led follow-up of laparoscopic adjustable gastric banding patients.
Inclusion Criteria:
  • All patients receiving laparoscopic banding surgery by the same surgeon performed at two different locations between April 2003 and November 2007 were included in the study
  • All patients fulfilled the criteria for surgery including: Body mass index (BMI) of 40kg/m2 or greater without comorbidities or 35kg/m2 or greater with comorbidities.
Exclusion Criteria:
There were no exclusions to this retrospective study of existing patients.
Description of Study Protocol:

Recruitment

All patients who underwent surgery by the same surgeon in the study period were included.

Design

  • This retrospective cohort design study observes the outcomes of two differing treatment programs based on location of surgery
  • One group received follow-up led by a dietitian and the other group received all follow-up by physician or specialized nurse.

Intervention

  • The dietitan-led protocol included nine post-operatve meetings led by the dietitian (two with a consultant radiologist for fluoroscopic guided adjustments)
  • In addition to telephone contact at less than one week post-op, and as needed throughout, meetings were scheduled at six weeks, three months, four to five months, six months, seven to eight months, 12 months, 18 months and 24 months.
  • The surgeon- or nurse-led protocol included nine post-operative meetings, including telephone contact less than one week post-op, initial clinic with a dieititan at four weeks, radiologist adjustment at two months and monthly clinic or clinical band fill with surgeon or nurse for the remaining six observation points.

Statistical Analysis

  • Statistical Package for Social Services 13 (SPSS Inc, Chicago, IL), with values expressed as mean and range
  • Signifcance: P<0.05.
Data Collection Summary:

Timing of Measurements

Measurements were analyzed within individualized treatment plans for each patient within the monitoring period of two years post-operative and summarized at three, six, 12 and 24 months.

Dependent Variables

  • Excess percentage of Body Mass Index Loss (EBIL)
  • Complications: Descriptive, including slippage, pouch dilatations, band erosion, infections, disconnections, port problems, band malfunctions, dysphagia, bleeding.

Independent Variables

  • Age
  • Sex.

Control Variables

Not applicable in retrospective cohort observation.

Description of Actual Data Sample:
  • Initial N: 1,335 (198 men, 1,137 women)
  • Attrition (final N): Same
  • Age: Mean, 42.5±9.98 (range, 18 to 71 years)
  • Ethnicity: Not specified.

Other Relevant Demographics

  • The dietitian-led participants were all Heart of England NHS Foundation patients, who were heavier, more likely to have comorbities and eligible for state-funded hospital care
  • The surgeon- or nurse-led participants were private obesity center patients, who were potentially more motivated, as they paid for the care.

Anthropometrics

  Dietitian-Led Surgeon-Led P-Value
Patients 316 1019 N/A
Age (yr) 44.8±10.2 years 41.9±9.9 years <0.01
Preop Weight (kg) 147.4±30.2kg 113.8±18.7kg <0.01
Preop BMI (kg/m2) 52.8±8.9kg/m2 41.7±5.2kg/m2 <0.01
Excess Weight (kg) 83.9±27.1kg 52±15.4kg <0.01

Location

United Kingdom.

Summary of Results:

Key Findings

A statistically higher percentage BMI loss was seen in the Surgeon- or Nurse-Led Group at three and six months. This group continued to have higher percentage loss over time but this was not statistically significant after one year.

Excess Percentage Body Mass Index Loss

  Dietitian-Led Surgeon-Led P-Value
EBIL at 3 Months 21.8±10.9 26.7±13.8 <0.01
EBIL at 6 Months 29.1±18.7 36.1±20.4 <0.01
EBIL at 12 Months 34±17.2 40.3±22.3 0.055
EBIL at 24 Months 38±22.5 51.3±26.6 0.056

 

Other Findings

  • The total number of patients who underwent dietitian-led follow-up was 316 compared with 1,019 for the Surgeon- or Nurse-Specialist-Led Group
  • Complete two-year follow-up data was available for 135 (90%) of the Dietitian-Led Group and 576 (88%) of the Surgeon-Led Group
  • The average number of band fills during the two years was 2.8 in the Dietitian-Led Group and 4.7 in the Surgeon- or Nurse-Led Group (P=0.63).
Author Conclusion:
Dietitian-led follow-up of bariatric patients after laparoscopic gastric banding is not associated with a negative effect on weight loss outcomes.
Funding Source:
University/Hospital: Heart of England NHS Foundation Hospital
Reviewer Comments:
Unequal distribution between dietitian-led and surgeon- or nurse-led groups.
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? No
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) No
  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? 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? 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? N/A
  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)? Yes
  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