International Journal of Obesity (2003) 27, 1167–1177
& 2003 Nature Publishing Group All rights reserved 0307-0565/03 $25.00
www.nature.com/ijo
PAPER
Clinical and cost effectiveness of surgery for morbid
obesity: a systematic review and economic evaluation
A Clegg1*, J Colquitt1, M Sidhu1, P Royle1 and A Walker2
1
Southampton Health Technology Assessments Centre (SHTAC), Wessex Institute for Health Research and Development,
University of Southampton, Southampton, UK; and 2Robertson Centre for Biostatistics, University of Glasgow Level 11 Boyd Orr
Building, University Avenue, Glasgow, UK
OBJECTIVE: To assess the clinical and cost effectiveness of surgery for people with morbid obesity.
DESIGN: A systematic review of randomised control trials (RCTs), prospective clinical trials and economic evaluations identified
from 14 electronic databases (including Medline, Cochrane library and Embase from their inception to October 2001),
bibliographies and consultation with experts and manufacturers was performed to assess the clinical and cost effectiveness of
different surgical procedures and nonsurgical management for morbid obesity. An economic evaluation was undertaken to
assess cost effectiveness in the UK.
SUBJECTS: People diagnosed as morbidly obese, defined as a body mass index (BMI) (weight in kilograms/height in metres2)
440 kg/m2, or with a BMI435 kg/m2 with serious comorbid disease, in whom previous nonsurgical interventions had failed.
MEASUREMENTS: The outcomes assessed included weight change, quality of life, peri- and postoperative morbidity and
mortality, revision rates and obesity comorbidities. Cost effectiveness was modelled from these data and presented as cost per
quality-adjusted life year (QALY).
RESULTS: Included studies differed in methodological quality. Surgery resulted in a significantly greater loss of weight (23–37 kg
more weight) than nonsurgical treatment, which was maintained to 8 years and led to improvements in quality of life and
comorbidities. The economic evaluation of surgery compared with nonsurgical management suggested that surgery was cost
effective at d11 000 per QALY. Comparisons of the different types of surgery were equivocal.
CONCLUSION: Surgery for morbid obesity appears to be clinically and cost effective. Because of the nature of the evidence,
particularly the uncertainty in the clinical and economic evaluations, it is difficult to distinguish between the different surgical
procedures.
International Journal of Obesity (2003) 27, 1167–1177. doi:10.1038/sj.ijo.0802394
Keywords: morbid; surgery; review; literature; model; economic
Introduction
Obesity is an increasing public health problem worldwide.
Some 31% of adults aged 20–74 y in USA in 1999–20001 and
17% of men and 21% of women in England in 19982 were
obese (body mass index (BMI)430 kg/m2). Trends among
children and adults suggest that the problem will continue
to grow.1–3 Obesity is associated with increased morbidity
and mortality from cardiovascular disease, type II diabetes,
cancer, degenerative diseases of the musculoskeletal system,
*Correspondence: Dr A Clegg, SHTAC, Wessex Institute for Health
Research and Development, Mailpoint 728, University of Southampton,
Southampton SO16 7PX, UK.
E-mail: [email protected]
Received 29 August 2002; revised 20 May 2003;
accepted 24 May 2003
reproductive disorders and respiratory disorders. The economic burden on society is considerable. Direct costs of
obesity in England were estimated at d480 million in 1998 or
about 1.5% of National Health Service (NHS) expenditure
and indirect costs through lost earnings at d2.1 billion.2 In
the UK, obesity tends to be managed either within the
primary care sector in the NHS or in private sector clinics
through advice on weight control, diet, physical exercise and
lifestyle, although referral to specialist services, drug therapy
or very low calorie diets (VLCD) may be considered. Surgery
is usually considered for people with morbid obesity when
all other measures have failed. Traditionally, these procedures have been viewed with some caution, as they are major
surgical procedures associated with significant risk of
morbidity and mortality. Recent advances, such as the use
of adjustable gastric bands and laparoscopic techniques,
Surgery for morbid obesity
A Clegg et al
1168
have brought renewed interest in the clinical and cost
effectiveness of these procedures.
In view of the continuing debate, the National Institute for
Clinical Excellence (NICE) in the UK, which provides
patients, health professionals and the public with guidance
on current best practice, was asked to provide national
guidance.4 This paper reports the results of a systematic
review and economic evaluation commissioned to assist
NICE in their deliberations. Although several reviews have
been published, either they were limited in the interventions
included, are known not to include recently published
evidence or do not consider the cost effectiveness of
procedures.5–10
Methods
We searched for published and unpublished studies in the
English language using 14 electronic databases, including
Medline, Cochrane library, and Embase from their inception
to October 2001(details of search strategy are presented
elsewhere and can be obtained from http://www.hta.nhsweb.nhs.uk/fullmono/mon612.pdf)).11 Additional references
were identified through searching bibliographies of related
publications and through contact with relevant experts and
industry. Studies reported as abstracts or conference presentations were excluded.
We included randomised control trails (RCTs), prospective
controlled clinical trials, economic evaluations and costing
studies of the different surgical procedures for morbid
obesity when compared with each other or with nonsurgical
interventions. Surgical interventions included jejunoileal
bypass, biliopancreatic diversion, gastric bypass, gastroplasty
and gastric banding that were used for treating patients
diagnosed as morbidly obese, defined as a BMI 440 kg/m2, or
with a BMI435 kg/m2 with serious comorbid disease, in
whom previous nonsurgical interventions had failed.
Although jejunoileal bypass and horizontal gastroplasty
procedures are rarely performed in the UK and elsewhere,
they were included as opinions differ as to their efficacy and
whether recent developments may have overcome apparent
limitations. Studies were included if they assessed clinical
effectiveness using outcome measures of weight change, fat
content, fat distribution, quality of life, peri- and postoperative morbidity and mortality, revision rates and
obesity–related comorbidities assessed as primary outcomes
at baseline and at least 12 months follow-up.
The quality of the studies that met the stated inclusion
criteria for the systematic review were assessed using
standard components for judging internal validity,12,13 and
through an adapted method for the external validity of
economic evaluations and model bias.11 Inclusion criteria
were applied, data were extracted and quality was assessed by
one reviewer and checked by a second reviewer, with any
differences resolved through consensus.
To compare clinical and cost effectiveness across different
studies, standard information on study characteristics,
International Journal of Obesity
Table 1 Benefits from treatment used in the economic evaluation
Nonsurgical
management
Gastric
bypass
Patients’ body mass index (BMI)
following treatment19–31,33,35,36,38,40,42,53
Baseline
45
45
Year 1
45
29
Year 2
45
29
Year 3
45
29
Year 4
45
29
Year 5
45
29
Years 6–20
45
45
Vertical banded Adjustable
gastroplasty
gastric
banding
45
34
35
36
37
38
45
Quality-adjusted life year (QALY)16
Change in QALYs 0.077 QALY 0.077 QALY 0.077 QALY
for a one unit,
change in BMI
Comorbidities F diabetes30,31,53
Baseline prevalence 0.1
Incidence to 8 y
0.023
Incidence after 8 y 0.023
0.025
0.0045
0.023
0.025
0.0045
0.023
45
36
32
31
32
30
45
0.077 QALY
0.025
0.0045
0.023
methods and results was extracted wherever possible for
the systematic review (limited data are presented in this
article, full details are available elsewhere).11 Clinical and
cost effectiveness were assessed through a narrative comparison of different outcomes. Meta-analysis was precluded due
to differences in, or insufficient details on, outcomes used,
patient characteristics or intervention used.
The economic evaluation developed for this study followed NICE guidance on the conduct of such studies, taking
the perspective of the NHS and Personal Social Services for
costs and benefits.4 Sources of costs were restricted to the
published information for 1999/2000,14,15 with resource use
based on scenarios developed from the evidence of clinical
effectiveness and expert advice. Efficacy was analysed in
terms of change in the health-related quality of life gained
from a change in BMI for a stereotypical person (baseline
weight 135 kg, BMI 45 kg/m2, aged 40 y, life expectancy 20 y)
and the impact of comorbidities (restricted to prevalence of
diabetes and costs averted from change in medication)
derived from studies of clinical effectiveness included in
the systematic review. Utility values originate from an
economic evaluation of orlistat.16 The evaluation provided
a range of utility values categorised by patient age and BMI,
based on time–trade-off values. Although other sources were
found,7,17 these utility values were thought to be the most
comprehensive. Costs and savings were discounted at 6%
and quality-adjusted life year (QALYs) at 1.5%. The assumptions underlying the economic evaluation were specific to
the UK setting and are summarised in Tables 1 and 2. These
were deliberately biased, within the range of the evidence
from the literature and expert opinion, against surgical
procedures with the intention of assessing the worst-case
Surgery for morbid obesity
A Clegg et al
1169
Table 2
Resource use and costs of care used in economic evaluation
NonSurgical management (3 y cycle)a
Years 1 and 2
GP visits
Dietician contacts
Practice nurse contacts
District nurse contacts
Nonsurgical
management
Gastric bypass
Vertical banded
gastroplasty
Adjustable
gastric banding
4
2
2
2
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
Year 3
As years 1 and 2 with 12 week very low calorie diet (two cans of Slimfast per day)
a
Surgical management
Preoperative care per patient
Outpatient visits
Dietitian consultations
Psychologist consultations
F
F
F
7
4
1
7
4
1
7
4
1
Operative care per patient33,35,37,40,42,45–54,61
Laparoscopic surgery
Patients undergoing procedure (%)
Time in theatre (minutes)
Length of stay (days)
Patients admitted to ITU care (1 night) (%)
Patients admitted to HDU care (1 night) (%)
F
F
F
F
F
90%
235
6a
7.6%
92.4%
100%
120a
4a
0%a
100%a
92%
150
5
7.6%
92.4%
F
F
F
F
F
10%
147.5a
7
21.1%
79.9%
0%a
0
0
0%
0%
8%
76
6
21.1%
79.9%
F
1%a
0.5%
F
15%a
15%a
0.5%
48% (open)
8% (laparoscopic)
F
F
F
F
F
F
6
2
4
4
12
2
6
2
4
4
12
2
6
2
4
4
12
2
F
F
F
4
4
2
4
4
2
4
4
2
F
F
F
d1550
2
2
1
d1550
2
2
1
d1550
2
2
1
d1550
Open surgery
Proportion of patients converted to open procedure
Time in theatre (min)
Length of stay (days)
Patients admitted to ITU care (1 night) (%)
Patients admitted to HDU care (1 night) (%)
Complications/revisions/additional procedures
Mortality rate
Proportion with complications and/or
Undergoing revisions/additional procedures
Post dischargea
Year 1
GP visits
Practice nurse visits
District nurse visits
Outpatient visits
Community dietitian visits
Psychologist consultations
Year 2
Outpatient clinics
Community dietician contacts
Psychology consultation
Years 3–20
Outpatient clinics
Community dietitian contacts
Psychologist consultations
Annual health care costs of diabetes62
ITU F intensive treatment unit; HDU F high dependency unit
Data has been informed by expert opinion.
a
scenario. Owing to the limited data available for the different
surgical procedures, data on quality of life and some resource
use and cost items were assumed not to differ. The model was
specified for a hypothetical cohort of 100 patients (90
females and 10 males) over a time horizon of 20 y following
surgery. One-way sensitivity analysis examining different
International Journal of Obesity
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Table 3
Comparison of the methodological quality of studies included in the assessment clinical effectiveness
Study
Random
assignment
Proper
sampling
Sample
size
Objective
outcomes
Blind
assessment
Eligibility
criteria
Attrition
reported
Comparable
groups
Generalizable
results
NR
NR
x
|
NR
x
|
NR
NR
|
|
|
x
NR
n/a
|
|
|
|
|
|
|
Sub
x
|
|
|
Comparison of different surgical procedures
Gastric bypass vs gastroplasty
Hall et al (1990)53
|
Howard et al (1995)33
NR
|
Laws et al (1981)46
Lechner et al (1981)34
NR
35,36
MacLean et al (1995)
NR
|
Naslund et al (1988)47–52
Pories et al (1982)41
|
Sugerman et al (1987)40
|
|
NR
|
NR
NR
|
NR
NR
|
NR
NR
NR
NR
NR
NR
NR
|
|
|
|
|
|
|
|
NR
NR
NR
NR
NR
NR
|
NR
|
|
Sub
|
x
|
Sub
|
|
|
x
x
|
|
|
|
|
|
Sub
|
|
|
|
|
|
|
|
|
|
|
|
|
Gastric bypass vs jejunoileostomy
Buckwater et al (1980)39,43,44
Griffen et al (1977)32
NR
NR
NR
NR
|
|
NR
NR
|
|
x
x
|
|
|
|
|
NR
|
NR
Sub
x
Sub
Uncertain
Vertical banded gastroplasty vs adjustable gastric banding
Nilsell et al (2001)38
|
NR
NR
|
x
|
|
|
|
Open vs laporoscopic gastric bypass
Nguyen et al (2001)54
Westling et al (2001)37
|
Sub
|
NR
|
|
x
Sub
|
|
|
|
|
x
|
|
Open vs laparoscopic adjustable silicone gastric banding
|
NR
De Wit et al (1999)42
|
|
NR
|
|
|
|
Surgery vs nonsurgical interventions
Andersen et al (1988)18,19
Danish Obesity Project20–22
Swedish obese subjects23–31
|
Sub
Vertical banded gastroplasty vs horizontal gastroplasty
Andersen et al (1987)45
|
|
|
| ¼ yes; x ¼ no; NR ¼ not reported; sub ¼ substandard or incomplete.
scenarios was carried out across a range of variables reflecting
the different views of experts (full details of economic
evaluation are provided elsewhere and can be obtained from
http://www.hta.nhsweb.nhs.uk/fullmono/mon612.pdf).11
Results
studies used objective outcome measures, only one study
adequately blinded their assessment.41 In total, 14 studies
used eligibility criteria to include patients18–34,37–40,42–44,47–54
and 13 studies18,19,32–36,38–44,47–54 had comparable groups at
baseline assessment. Attrition was adequately reported in 13
studies18–31,33,35–38,40–42,47–54 and results were thought to be
generalisable in 17 studies.18–44,46–54
Systematic review of clinical effectiveness of surgery for
morbid obesity
We included 17 RCTs and one nonrandomised trial: two
RCTs18–22 and one non-randomised clinical trial23–31 comparing surgery with nonsurgical management and 15 RCTs
comparing different types of surgery. Characteristics of, and
results from, the RCTs, and nonrandomised trial are
summarised in Tables 3 and 4.
The methodological quality of the included studies varied
(see Table 3). Of the 18 studies included to assess clinical
effectiveness, seven lacked an adequate description of the
method of allocation,18–36 12 failed to discuss or reported
inappropriate sampling methods20–44 and 14 did not provide
a sample size or power calculation.20–41,43–52 Although all 18
Clinical effectiveness of surgery compared with
nonsurgical management
The three studies comparing surgery with nonsurgical
management assessed different interventions, specifically
horizontal gastroplasty and diet compared with VLCD,18,19
jejunoileostomy with medical management20–22 and either
vertical banded gastroplasty, gastric banding or gastric
bypass with nonsurgical management.23–31 All three of these
studies showed statistically significant weight loss following
surgery compared with nonsurgical management at 2 y
follow-up, losing between 23 and 37 kg more weight
(Table 4).18–31 Two studies assessed weight loss beyond 2 y,
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Table 4
Summary of the key outcomes of weight change following treatment
Study details
Measures of weight change
Surgery vs nonsurgical interventions
Andersen et al,18,19
Design: RCT
Intervention: horizontal gastroplasty (GP) and diet (n=27);
very low calorie diet (VLCD) (n=30)
Patients: Z60% overweight
20–22
Net weight change
12 months VLCD 18 kg; GP 23 kg (P=ns)
18 months VLCD 10.5 kg; GP 18.5 kg (P=ns)
24 months VLCD 9 kg; GP 32 kg (Po0.05)
Danish Obesity Project
Design: RCT
Intervention: Medical management (n=66); Jejunoileostomy (n=130)
Patients: Z80% overweight
Median weight loss (range)
24 months medical management 5.9 kg (11.9, 40.4);
jejunoileostomy 42.9 kg (20.5, 108.5) (Po0.001)
Swedish obese subjects23–31
Design: Cohort study with matched controls.
Intervention: surgical (vertical banded gastroplasty; gastric
banding; gastric bypass); nonsurgical.
Patients: BMI X38 kg/m2women, X34 kg/m2 men
Weight loss
24 months surgical 28.0 kg; nonsurgical 0.0 kg (Po0.001)
8 y surgical 20.1 kg; nonsurgical 0.7 kg (gain) (Po0.001)
Comparison of different surgical procedures
Gastric bypass vs gastroplasty
Hall et al. (1990)53
Design: RCT
Interventions: vertical
Gastroplasty (GP) (n=106);
Gastrogastrostomy (GG) (n=105); Roux-en-Y gastric bypass (RYGB) (n=99).
Patients: >160% ideal weight
Median body weight (range)
Baseline GP 112 kg (88–157); GG 110 kg (78–162); RYGB 115 kg (83–170)
12 months GP 76 kg (50–115);GG 81 kg (56–132); RYGB 73 kg (53–128)
24 months GP 75 kg (49–121); GG 86 kg (58–132); RYGB 71 kg (49–140)
36 months GP 79 kg (44–125); GG 93 kg (60–156); RYGB 76 kg (55–140)
Howard et al (1995)33
Design: RCT
Interventions: gastric bypass (GB) (n=20);
vertical banded gastroplasty (VBG) (n=22)
Patients: BMI>40 kgm2
Percent of excess weight loss compared to maximum excess weight
12 months GB 78%, VBG 52%, Po0.05
60 months GB (n=6) 70%, VBG (n=6) 37%, Po0.05
Laws et al (1981)46
Design: RCT
Intervention: gastric bypass (GB) (n=27); gastric partitioning (GP) (n=26)
Patients: twice ideal weight for height
Fraction of initial weight
12 months GB 0.65; GP 0.84 (Po0.001)
Lechner et al (1981)34
Design: RCT
Intervention: horizontal gastroplasty (GP) (n=50); Roux-en-Y
gastric bypass (RYGB) (n=50)
Patients: X45 kg over metropolitan life insurance desirable weight table
Mean weight loss (7s.d.)
12 months RYGB 45.2 kg (711.3); GP 33.5 kg (713.3) (Po0.01)
Percent of excess weight loss (7s.d.)
12 months RYGB (n=15) 64.0% (713.9); GP (n=14) 54.1% (718.6) (P=ns)
MacLean et al (1995)35,36
Design:RCT
Interventions: vertical banded gastroplasty (VBG) (n=54); Roux-en-Y
gastric bypass (RYGB) (n=52)
Patients: not stated
Success rate (BMIo35 kg/m2 or >50% excess weight and no reoperation)
B36 months VBG 39%;RYGB 58% (P=ns)
B78 months VBG 16%; RYGB 34% (P=ns)
Naslund et al (1988)47–52
Design: RCT
Interventions: gastric bypass (GBY) (n=29); gastroplasty (GPL) (n=28)
Patients: Morbidly obese (Broca’s Index 1.50)
Mean weight loss (7s.d.)
12 months GB 42.3 kg (710.9); GP 29.9 kg (710.0) (Po0.001)
24 months GB 42.9 kg (713.6); GP 27.6 kg (710.7) (Po0.001)
36 months GB 38.4 kg (713.2); GP 24.7 kg (713.1) (Po0.001)
Percent over ideal weight(7s.d.)
12 months GB 32% (719.7); GP 54% (721.3) (Po0.001).
24 months GB 32% (718.1); GP 57% (724.0) (Po0.001).
Pories et al (1982)41
Design: RCT
Intervention: Roux-en-Y gastric bypass (RYGB) (n=42)
Gastric partition (GP) (n=45)
Patients: at least twice their normal weight
Percentage of original weight (standard error):
12 months GP 76.9% (1.36); RYGB 61.8% (1.04)
18 months GP 81.0% (2.64); RYGB 60.0% (2.02)
Sugerman et al (1987)40
Design: RCT
Intervention:Roux-en-Y Gastric Bypass (RYGB) (n=20); Vertical Banded
Weight loss (s.d.) (kg)
12 months RYGB 43.5 kg (711.3); VBG 32.2 kg (710.9) (Po0.001)
24 months RYGB 43.5 kg (715.4); VBG 30.4 kg (712.2) (Po0.001)
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Table 4
(Continued)
Study details
Gastroplasty (VBG) (n=20)
Patients: >45 kg above ideal weight
Gastric bypass vs jejunoileastomy
Buckwater et al (1980)39,43,44
Design: RCT
Intervention: jejunoileal bypass (JB) (n=19); gastric bypass (GB) (n=19)
Patients: at least twice normal body weight or Z45 kg overweight for 5 y
Measures of weight change
36 months RYGB 41.3 kg (712.7); VBG 27.2 kg (714.5) (Po0.01)
Percent excess weight lost (standard deviation):
12 months RYGB 68% (717); VBG 43% (718) (Po0.001).
24 months RYGB 66% (729); VBG 39% (724) (Po0.001).
36 months RYGB 62% (718); VBG 37% (719) (Po0.001).
Percent (mean) excess weight loss
12 months JB 53%, GB 44%
24 months JB 66%, GB 50%
36 months JB 64%, GB 55% (P not stated).
Griffen et al (1977)32
Design: RCT
Intervention: jejunoileal bypass (JB) (n=27); gastric bypass (GB) (n=32)
Patients: 50 kg over ideal weight
Vertical banded gastroplasty vs horizontal gastroplasty
Mean (range) weight loss
12 months GB (n=18) 51.0 kg (13.0–100), JB (n=22) 57.9 kg
(15.2–116.3) (P=ns).
Andersen et al (1987)45
Design: RCT
Intervention: vertical banded gastroplasty (VBG) (n=23);
Horizontal gastroplasty (GP) (n=22). All pretreated with a
very low calorie diet (VLCD)
Patients: Morbid obesity, Z40% of initial overweight lost and maintained
Vertical banded gastroplasty vs adjustable gastric banding
Median (range) preoperative weight loss
GP 30.3 kg (10.3–88.6); VBG 34.0 kg (17.4–75.3).
Median (range) postoperative weight loss
12 months GP (n=20) –1 kg (gained) (15.0–36.5),
VBG (n=21) 9.7 kg (28.2–28.7) Po0.001.
Weight reduced compared with preoperative. Weight for VBG
(Po0.01) but not GP.
Median (range) total weight loss
12 months VLCD+GP 32.6 kg (3.7–125.1), VLCD+VBG 48.5 kg
(6.4–104.0), (Po0.02)
Nilsell et al (2001)38
Study design: RCT
Intervention: adjustable gastric banding (AGB) (n=29)
vertical banded gastroplasty (VBG) (n=30)
Patients: BMI >40 kg/m2
Open vs laparoscopic gastric bypass
Weight (mean (s.e.)
Baseline AGB 124 kg (29); VBG
1 y AGB 98 kg (28); VBG 82 kg
2 y AGB 88 kg (23); VBG 85 kg
3 y AGB 85 kg (13); VBG 90 kg
4 y AGB 86 kg (17); VBG 95 kg
5 y AGB 81 kg (16); VBG 88 kg
Nguyen et al (2001)54
Design: RCT
Intervention: Laparoscopic gastric bypass (n=79); open gastric bypass (n=76)
Patients: BMI 40–60 kg/m2
Percentage excess body weight loss (s.d.)
12 months: laparoscopic (n=29) 68% (715); open (n=25)
62% (714) (P=0.07)
Westling et al (2001)37
Design: RCT
Intervention: laparoscopic gastric bypass (lap) (n=30);
Open Roux-en-Y gastric bypass (n=21)
Patients: BMI >40 or >35 kg/m2 with significant comorbidity
Open vs laparoscopic adjustable silicone gastric banding
Mean change in BMI
12 months: laparoscopic 14 kg/m2 (73); open 13 kg/m2 (73) (P=ns).
De Wit et al (1999)42
Study design: RCT
Intervention: laparoscopic
Adjustable silicone gastric banding (ASGB) (n=25); open ASGB (n=25)
Patients: BMI >40 kg/m2
Mean weight loss
12 months laparoscopic ASGB 35 kg, open ASGB 34.4 kg (P=ns).
Reduction from baseline Po0.05 for laparoscopic ASGB and open ASGB.
with one study finding a statistically significant 21 kg weight
loss maintained at 8 y following surgery.23–31 Two studies
assessed the effects of surgery and nonsurgical management
on quality of life and comorbidities.20–31 Quality of life was
shown to improve significantly following surgery compared
to nonsurgical management on many somatic symptoms,
psychological symptoms and social factors at 15 months
International Journal of Obesity
123 kg (30);
(25);
(29);
(15);
(15);
(16);
(Po0.05)20–22 and on all Health Related Quality of Life
measures at 2 y follow-up.23–31 Surgery had a statistically
significant beneficial effect on blood pressure,20–31 hypertension,23–31 and diabetes compared to nonsurgical management at 2 y follow-up.23–31 The effects on diabetes were
maintained at 8 y.23–31 Although there were no operative
deaths reported, there were complications from surgery
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A Clegg et al
1173
(eg wound infection and subphrenic abscess) and side effects
from the surgical procedures (eg vomiting). Some patients
required reoperation or reversal of the procedure.
Complications differed little between the procedures,
although vertical banded gastroplasty patients suffered
significantly more occasional vomiting.45 Reoperations,
revisions and reversals were not reported.
Clinical effectiveness of different surgical procedures
Gastric bypass vs gastroplasty. Eight RCTs compared gastric
bypass with different types of gastroplasty, three with
vertical banded gastroplasty,33,35,36,40 four with horizontal
gastroplasty34,41,46–52 and one with vertical gastroplasty and
gastrogastrostomy.53 Seven of the eight RCTs showed that
gastric bypass led to significantly greater weight loss than
from
gastroplasty,
losing
an
additional
6–12 kg
(Table 4).33,34,40,41,46–53 In four RCTs the differences in
weight loss remained significant beyond 1 y follow-up, to
3 y 40,47–53 and 5 y.33 None of the RCTs assessed the effects of
surgery on quality of life. Three RCTs assessed the effect of
surgery on comorbidities at either 1 or 3 y follow-up,41,47–53
showing improvements in diabetes, hypertension, joint pain
and asthma. While none of the RCTs reported perioperative
deaths, three RCTs reported five postoperative deaths
following gastric bypass34,40,53 and one following horizontal
gastroplasty.34 Although complications were common following all forms of surgery, dumping syndrome and heartburn were more evident following gastric bypass than
gastroplasty.47–52 Revisions, reoperations and/or conversions
were more common following gastroplasty (vertical banded
gastroplasty 2–53% of patients, horizontal gastroplasty
1–19% of patients) than following gastric bypass (0–39%
of patients).34–36,40,41,47–53
Vertical banded gastroplasty vs adjustable gastric
banding. One RCT compared vertical banded gastroplasty
with adjustable gastric banding.38 At 5 y, weight-loss following adjustable gastric banding exceeded that following
vertical banded gastroplasty (8 kg difference), although it
was not statistically significant (Table 4). Quality of life and
comorbidities were not assessed. One postoperative death
was reported following vertical banded gastroplasty and
adjustable gastric banding. There was little difference in
complications between the procedures. A third of vertical
banded gastroplasty patients were reoperated due to staple
line disruption or strictures of the stoma, while 10% of
adjustable gastric banding patients were reoperated due to
gastric pouch dilation.
Gastric bypass vs jejunoileal bypass. Two RCTs compared
gastric bypass with jejunoileal bypass.32,39,43,44 Although the
two RCTs showed slightly greater weight loss (9% or 7 kg
more weight loss) following jejunoileal bypass than gastric
bypass at 1-y follow-up, differences were not statistically
significant (Table 4). One RCT found that differences
continued at 3 y.39,43,44 Quality of life and comorbidities
were not assessed by either RCT. Two RCTs reported two
postoperative deaths following gastric bypass and one
following jejunoileal bypass. Serious complications associated with liver disease affected 80% of the patients
undergoing a jejunoileal bypass.32 Other complications,
including wound and urinary tract infection, were evident
among gastric bypass and jejunoileal bypass patients.32,39,43,44 Reoperation, revision or reversal was required by 16% of gastric bypass and 32% of jejunoileal
bypass patients.32,39,43,44
Vertical banded gastroplasty vs horizontal gastroplasty. The one RCT comparing vertical banded gastroplasty
with horizontal gastroplasty after pretreatment with VLCD
found statistically significant weight loss at 1 y following
vertical banded gastroplasty (9.7 kg) but weight gain after
horizontal gastroplasty (1 kg) (Table 4).45 Quality of life and
comorbidities were not assessed. No deaths were reported.
Open vs laparoscopic gastric bypass. Two RCTs compared
open with laparoscopic gastric bypass. Although the two
RCTs showed weight loss following gastric bypass (approximately 30% loss of excess weight), neither RCT found a
statistically significant difference in weight loss between the
procedures (Table 4).37,54 Early differences in quality of life
were assessed using the Short Form Health Survey (SF-36) at 1
month and the Moorehead-Ardelt questionnaire at 3 months
that favoured laparoscopic gastric bypass, disappeared at
later follow-up (3 and 6 months respectively).54 One postoperative death was reported following laparoscopic gastric
bypass surgery.37 There were limited differences between the
procedures when comparing major, minor and late complications. Reoperations were more common following laparoscopic than open procedures. Although laparoscopic
procedures had longer operative times, they caused significantly less blood loss, required shorter intensive care unit
stay, shorter hospital stay and shorter time to return to
activities of daily living and work.37,54
Open vs laparoscopic adjustable silicone gastric banding.
One RCT42 compared open and laparoscopic adjustable
silicone gastric banding. Although both procedures resulted
in statistically significant weight loss at 1-y follow-up
(approximately 35 kg), there were no statistically significant
differences between the procedures (Table 4). Neither quality
of life nor comorbidities were assessed. Surgical and early
postoperative complications showed limited difference between the procedures. Readmissions and overall length of
stay were significantly higher among those undergoing open
compared to laparoscopic procedures. A small proportion of
laparoscopic patients converted to open procedures.
Systematic review of cost effectiveness of surgery for morbid
obesity. Searching found four economic evaluations, three
comparing different types of surgery with nonsurgical
International Journal of Obesity
Surgery for morbid obesity
A Clegg et al
1174
Table 5
Characteristics of included economic studies
Author
Martin et al (1995)56
Van Gemert et al (1999)17
Base year prices
Intervention
Unclear
Unclear
Surgical: Roux-en-Y gastric bypass. Treatment: vertical banded
gastroplasty
Chua et al (1995)57
Medical: very low calorie diet F No treatment: no treatment
consumption for at least 12 weeks given
plus weekly behavioural
modification meetings for at least
4 months.
Study type
Cost effectiveness
Cost effectiveness and cost-ofillness
Patient group
Obese
Morbidly obese (BMI>40 kg/m2)
Perspective
Unclear
Unclear
Industry role
Unclear
Unclear
Country of origin US
The Netherlands
Results
Cost per pound lost: surgery
Vertical banded gastroplasty cost
US$250 to US$750; medical
effective compared to no
therapy US$100 to US$1600
treatment, saving US$4004 to
(2 to 6 years)
US$3928/quality adjusted
life year (over lifetime of patient)
Sensitivity
analysis
None
Limited to cost-of-illness
management and one comparing different types of surgery.17,55–57 The characteristics of, and results from, the
economic evaluations are summarised in Table 5. Judgement
of the methodological quality of these economic evaluations
was based on standard criteria for internal validity that assess
the approaches used to minimise four sources of bias,12
specifically framing of the model (ie well-defined question,
description of alternatives, study type and clinical effectiveness of technology), model construction (ie identification,
measuring and credibility of costs and consequences),
reliability of estimates used (ie discounting applied, incremental analysis and modelling undertaken appropriately)
and the way sensitivity analysis was performed (full details
provided elsewhere).11 Using these criteria, and with limited
access to models, one study appeared to be the most robust,
only lacking adequate discussion of model construction.17
The other studies had some inadequacies in model construction, reliability of estimates and sensitivity analysis.55–57
Issues concerning external validity were less clear, with all
four studies set in different health care systems. As such
comparisons between the results of economic evaluations
should be made with caution, due in part to the different
perspectives adopted and, consequently, the different component costs and benefits included.
Cost effectiveness of surgery in the UK
With no relevant cost effectiveness studies available, an
economic evaluation was undertaken to consider cost
International Journal of Obesity
Sjostrom et al (1995)55
Unclear
Unclear
Laparoscopy: Laparoscopic vertical Surgery: Banding or vertical
banded gastroplasty
banded gastroplasty, or gastric
bypass
Conventional: not clearly
Open: open vertical banded
gastroplasty and Open Roux-en-Y described.
gastric bypass
Cost effectiveness
Cost effectiveness
Morbidly obese
Unclear
Unclear
US
Laparoscopic vertical banded
gastroplasty compared to open
gastric bypass had lower costs
(US$ 12 800 compared to US$16
700 1993/1994 prices) shorter
hospital stay but longer
operating time
None
Obese
Society
Unclear
Sweden
Direct cost of surgery 16.5 million
SEK/100 surgical patients/10 years
F patients lost 30–40 kg over 2 y
and Health-related quality of life
improved.
None
effectiveness in the UK (Tables 1, 2 and Table 6). It focused
on the three types of surgery that appeared most clinically
effective, specifically gastric bypass (Roux-en-Y), vertical
banded gastroplasty and adjustable gastric banding, and
nonsurgical management. Horizontal gastroplasty and jejunoileostomy were excluded as they are rarely carried out in
the UK and jejunoileostomy is widely regarded as unsafe.58,59
Comparison of surgery with nonsurgical management
showed that surgery offered additional QALYs at an additional cost, with gastric bypass (d6289/QALY), silicone
adjustable gastric banding (d8527/QALY) and vertical
banded gastroplasty (d10 237/QALY) having net cost per
QALY below d11 000. When comparing different surgical
procedures the difference was less clear. Gastric bypass
appeared to have a modest net cost per QALY gained
compared to vertical banded gastroplasty (d742/QALY). In
contrast, adjustable silicone gastric banding had large net
cost per QALY gained compared to gastric bypass (d256 856/
QALY). However, these incremental cost-effectiveness ratios
were based on small differences in clinical effectiveness and
should be interpreted with extreme caution. Longer-term
follow-up studies are required before a definitive judgement
can be made about the most clinically and cost effective
surgical technique. Several different scenarios were examined in the one-way sensitivity analyses for gastric bypass
surgery compared to nonsurgical management. Increased
length of hospital stay to 14 days (d10 323/QALY) increased
costs of pre- and postoperative care to include additional
surgical outpatient and dietitian follow-up and a VLCD
Surgery for morbid obesity
A Clegg et al
1175
Table 6
Net cost per quality adjusted life year (QALY) gained for each intervention
Comparison
Vertical banded gastroplasty vs nonsurgical management
Silicone adjustable gastric banding vs nonsurgical management
Silicone adjustable gastric banding vs vertical banded gastroplasty
Gastric bypass vs nonsurgical management
Gastric bypass vs vertical banded gastroplasty
Silicone adjustable gastric banding vs gastric bypass
(d7255/QALY), increased weight loss from nonsurgical
management from no weight loss to a loss of 3 on BMI
(d8931/QALY), decreased weight loss from surgery by 50%
(d16 819/QALY), increased costs for developing the service
through poorer performance and higher training costs (d20
768/QALY), decreased costs of treating comorbidities by
halving cost of diabetic care (d8715/QALY) and decreased
utility gains to one-third (d18 867/QALY) resulted in cost per
QALYs below d21 000. Caution should be taken when
comparing surgical procedures as the economic evaluation
was based on several assumptions.
Comment
Reasonably good-quality evidence comparing the clinical
effectiveness of surgery and nonsurgical management
showed that surgery resulted in significantly greater longterm weight loss (23 to 37 kg more weight lost at 2 y with
21 kg difference maintained to 8 y) and improvements in
quality of life and comorbidities. Evidence of clinical
effectiveness of different surgical procedures was of varying
methodological quality. Comparison of the different types of
surgery showed that gastric bypass appeared more beneficial,
with greater weight loss (6 to 14 kg more weight) and/or
improvements in comorbidities and complications than
either gastroplasty or jejunoileal bypass. Assessment of open
and laparoscopic procedures showed laparoscopic procedures had longer operative time, fewer serious complications, reduced intensive care unit and hospital stay and
earlier return to activities of daily living and work. The
economic evaluation showed that surgery appears cost
effective compared to nonsurgical management assuming a
threshold of d30 000, offering additional QALYs at an
additional cost under d11 000/QALY. Comparison of the
different surgical procedures was less certain. One way
sensitivity analyses suggested that surgery compared to
nonsurgical management remained cost effective under a
range of assumptions.
Consistent methods for undertaking systematic reviews
were applied,60 with support from an expert advisory group
of clinicians, health professionals and academics. Potential
limitations were exclusion of nontrial evidence affecting
newer surgical procedures with a limited evidence base, lack
Additional QALYs
Additional cost
Net cost per QALY gained
26
45
19
45
19
0.4
d266 275
d383 102
d116 826
d280 020
d13 745
d103 082
d10 237
d8527
d6176
d6289
d742
d256 856
of follow-up with authors to clarify study details, and limited
information available for the economic evaluation. Possible
inadequacies in primary studies may undermine the evidence. Frequently, initial weight loss has been modified by
subsequent weight regain. To adequately assess efficacy,
studies should have a long-term follow-up, yet only four of
18 studies reported outcomes at 5 y and beyond. Limited
attention was given to quality of life with only three of 18
studies including some form of assessment. No account was
taken of the role of patient preference for different treatment
options, which would affect the implementation of a service.
Most studies focused on morbidly obese women aged
30–50 y old. Greater benefits may accrue among younger
adults, particularly men. Methodological quality of the
studies appeared poor through noncompliance with, or poor
reporting of, key aspects of their methods, providing the
potential for bias. As a consequence further research should
examine the epidemiology of morbid obesity, as well as
undertake good quality controlled trials of the different
procedures with follow-up beyond 5 y, include quality of life
outcomes, and prospective economic evaluations.
Conclusions
Surgery appears to be a clinically and cost-effective treatment
for people who are morbidly obese (BMI 440 kg/m2) or have
a BMI 435 kg/m2 with significant comorbid conditions. Due
to the nature of the evidence, particularly the uncertainty in
the economic evaluation, it is difficult to distinguish
between the different procedures. With evidence continuing
to emerge, we recommend that our findings are periodically
reviewed and revised.
Contributors
All authors contributed to the design of the protocol,
execution of the review and content of the paper. AC
coordinated the project and developed the research protocol.
PR undertook the searching. JC, AC, MS and AW applied the
inclusion criteria and extracted data with PR. All authors
were involved with drafting the paper, AC, JC and AW
providing critical review and revisions. AC and AW are
guarantors for the paper.
International Journal of Obesity
Surgery for morbid obesity
A Clegg et al
1176
Acknowledgements
We thank the advisory group for advice and peer review of
the research protocol and/or a draft of the original report for
NICE, including Professor JN Baxter, Professor of Surgery,
University of Wales; Sir Alfred Cuschieri, Professor of Surgery,
University of Dundee; Professor Philip James, Chairman,
International Obesity Task Force; Professor Roland Jung,
Chief Scientist to Scottish Executive, Dundee; Dr AM Mir,
Consultant Physician and Senior Lecturer, University of
Wales College of Medicine, Cardiff; Mr JDB Miller, Consultant Surgeon, Dr Gray’s Hospital, Elgin; Dr Ian Campbell,
NOF Chairman, Nottingham; Dr JPH Wilding, Reader in
Medicine, University Hospital Aintree, Liverpool; Mr Peter
Sedman, Consultant Surgeon, Hull Royal Infirmary; Ms Mary
O’Kane, Chief Dietitian, The General Infirmary, Leeds;
Professor Bruce Campbell, Consultant General Surgeon,
Royal Devon & Exeter Hospital, Exeter. We thank Ms Liz
Hodson for support with obtaining information; Dr Norman
Waugh and Dr Emma Loveman, SHTAC, University of
Southampton; Dr Alison Avenell, University of Aberdeen
Medical School, Aberdeen; Mr David Carson, Head of
Financial Performance Management, Tayside Health Board,
Dundee; Dr Janis Baird, Specialist Registrar in Public Health
Medicine, University of Southampton. This work was funded
by the NHS R&D HTA Programme. The views and opinions
expressed therein are those of the authors and do not
necessarily reflect those of the NHS Executive.
References
1 Flegal KM, Carroll MD, Ogden CL, Johnson CL. Prevalence and
trends in obesity among US adults, 1999–2000. JAMA 2002; 288:
1723–1727.
2 National Audit Office. Tackling obesity in England: report by
the Comptroller and Auditor General. London: Stationery Office:
2001.
3 Ogden CL, Flegal KM, Carroll MD, Johnson CL. Prevalence
and trends in overweight among US children and adolescents,
1999–2000. JAMA 2003; 288: 1728–1732.
4 National Institute for Clinical Excellence. Available from URL:
http://www.nice.org.uk/. 2002.
5 Glenny AM, O’Meara S, Melville A, Sheldon TA, Wilson C. The
treatment and prevention of obesity: a systematic review of the
literature. Int J Obes Relat Metab Disord 1997; 21: 715–737.
6 NHS Centre for Reviews and Dissemination. Systematic review of
interventions in the treatment and prevention of obesity. CRD Report
10. University of York: York; 1997.
7 Bryant J, Best L, Milne R. Gastroplasty for severe obesity.
Southampton: Wessex Institute for Health Research and Development; 1997. Development and Evaluation Committee Report
No. 68.
8 ASERNIP. Laparoscopic adjustable gastric banding for the treatment of obesity. Vol 9. Adelaide: ASERNIP; 2000.
9 Schneider WL. Laparoscopic adjustable gastric banding for clinically
severe (morbid) obesity, Vol 7(b). Alberta: Alberta Heritage Foundation for Medical Research; 2000.
10 Robertson A, Douglas S, Waugh N. Gastric surgery for obesity.
Aberdeen: SHPIC; 1998.
11 Clegg A, Sidhu MK, Colquitt J, Royle P, Loveman E, Walker A.
Clinical and cost effectiveness of surgery for people with morbid
obesity. Health Technol Assess 2002; 6: 1–153.
12 Drummond MF, Jefferson TO. Guidelines for authors and peer
reviewers of economic submissions to the BMJ. BMJ 1996; 313:
275–283.
International Journal of Obesity
13 Spitzer WO, Lawrence V, Dales R, Hill G, Archer MC, Clark P et al.
Links between passive smoking and disease: a best-evidence
synthesis. Clin Invest Med 1990; 13: 17–42.
14 National Health Services in Scotland Information and Statistics
Division. Scottish Health Service Costs 1999/2000. Available from
URL:
http://www.show.scot.nhs.uk/isd/Scottish_Health_Statistics/subject/Costs/2000/costs2000.pdf. 2000.
15 Netten A, Curtis L. Unit costs of health and social care. PSSRU:
University of Kent, Canterbury; 2000.
16 Hakim Z, Wolf A, Garrison LP. Estimating the effect of changes in
body mass index on health state preferences. Pharmacoeconomics
2002; 20: 393–404.
17 van Gemert WG, Adang EM, Kop M, Vos G, Greve JW, Soeters PB.
A prospective cost-effectiveness analysis of vertical banded
gastroplasty for the treatment of morbid obesity. Obes Surg
1999; 9: 484–491.
18 Andersen T, Stokholm KH, Backer OG, Quaade F. Long-term
(5-year) results after either horizontal gastroplasty or verylow-calorie diet for morbid obesity. Int J Obes Relat Metab Disord
1988; 12: 277–284.
19 Andersen T, Backer OG, Stokholm KH, Quaade F. Randomized
trial of diet and gastroplasty compared with diet alone in morbid
obesity. N Engl J Med 1984; 310: 352–356.
20 Quaade F. Studies of operated and nonoperated obese patients.
An interim report on the Scandinavian Obesity Project. Am J Clin
Nutr 1977; 30: 16–20.
21 Stokholm KH, Nielsen PE, Quaade F. Correlation between initial
blood pressure and blood pressure decrease after weight loss: a
study in patients with jejunoileal bypass versus medical treatment
for morbid obesity. Int J Obes Relat Metab Disord 1982; 6: 307–312.
22 Backer O, Gudmand-Hoyer E, Andersen B, Baden H, Martiny P,
Juhl E and other members of Danish Obesity Project. Randomised
trial of jejunoileal bypass versus medical treatment in morbid
obesity. The Danish Obesity Project. Lancet 1979; 2: 1255–1258.
23 Karason K, Wallentin I, Larsson B, Sjostrom L. Effects of obesity
and weight loss on left ventricular mass and relative wall thickness:
survey and intervention study. Br Med J 1997; 315: 912–916.
24 Karason K, Wikstrand J, Sjostrom L, Wendelhag I. Weight loss and
progression of early atherosclerosis in the carotid artery: a fouryear controlled study of obese subjects. Int J Obes Relat Metab
Disord 1999; 23: 948–956.
25 Karason K, Molgaard H, Wikstrand J, Sjostrom L. Heart rate
variability in obesity and the effect of weight loss. Am J Cardiol
1999; 83: 1242–1247.
26 Karason K, Lindroos AK, Stenlof K, Sjostrom L. Relief of
cardiorespiratory symptoms and increased physical activity after
surgically induced weight loss: results from the Swedish Obese
Subjects study. Arch Intern Med 2000; 160: 1797–1802.
27 Karlsson J, Sjostrom L, Sullivan M. Swedish obese subjects
(SOS)Fan intervention study of obesity. Two-year follow-up of
health-related quality of life (HRQL) and eating behavior after
gastric surgery for severe obesity. Int J Obes Relat Metab Disord
1998; 22: 113–126.
28 Narbro K, Agren G, Jonsson E, Larsson B, Naslund I, Wedel H,
Sjostrom L. Sick leave and disability pension before and after
treatment for obesity: a report from the Swedish Obese Subjects
(SOS) study. Int J Obes Relat Metab Disord 1999; 23: 619–624.
29 Sjostrom CD, Lissner L, Wedel H, Sjostrom L. Reduction in
incidence of diabetes, hypertension and lipid disturbances after
intentional weight loss induced by bariatric surgery: the SOS
Intervention Study. Obes Res 1999; 7: 477–484.
30 Sjostrom CD, Peltonen M, Wedel H, Sjostrom L. Differentiated
long-term effects of intentional weight loss on diabetes and
hypertension. Hypertension 2000; 36: 20–25.
31 Sjostrom CD, Peltonen M, Sjostrom L. Blood pressure and pulse
pressure during long-term weight loss in the obese: the Swedish
obese subjects (sos) intervention study. Obes Res 2001; 9: 188–195.
32 Griffen-WO J, Young VL, Stevenson CC. A prospective comparison of gastric and jejunoileal bypass procedures for morbid
obesity. Ann Surg 1977; 186: 500–509.
Surgery for morbid obesity
A Clegg et al
1177
33 Howard L, Malone M, Michalek A, Carter J, Alger S, Van Woert J.
Gastric bypass and vertical banded gastroplasty F a prospective
randomized comparison and 5-year follow-up. Obes Surg 1995; 5:
55–60.
34 Lechner GW, Callender AK. Subtotal gastric exclusion and gastric
partitioning: a randomized prospective comparison of one
hundred patients. Surgery 1981; 90: 637–644.
35 MacLean LD, Rhode BM, Sampalis J, Forse RA. Results of the
surgical treatment of obesity. Am J Surg 1993; 165: 155–160.
36 MacLean LD, Rhode BM, Forse RA, Nohr C. Surgery for
obesity F an update of a randomized trial. Obes Surg 1995; 5:
145–153.
37 Westling A, Gustavsson S. Laparoscopic vs open Roux-en-Y gastric
bypass: a prospective, randomized trial. Obes Surg 2001; 11:
284–292.
38 Nilsell K, Thorne A, Sjostedt S, Apelman J, Pettersson N.
Prospective randomised comparison of adjustable gastric banding
and vertical banded gastroplasty for morbid obesity. Eur J Surg
2001; 167: 504–509.
39 Buckwalter JA. Clinical trial of surgery for morbid obesity. South
Med J 1978; 71: 1370–1371.
40 Sugerman HJ, Starkey JV, Birkenhauer R. A randomized prospective trial of gastric bypass versus vertical banded gastroplasty for
morbid obesity and their effects on sweets versus non-sweets
eaters. Ann Surg 1987; 205: 613–624.
41 Pories WJ, Flickinger EG, Meelheim D, Van Rij AM, Thomas FT.
The effectiveness of gastric bypass over gastric partition in
morbid obesity: consequence of distal gastric and duodenal
exclusion. Ann Surg 1982; 196: 389–399.
42 de Wit LT, Mathus-Vliegen L, Hey C, Rademaker B, Gouma DJ,
Obertop H. Open versus laparoscopic adjustable silicone gastric
banding F A prospective randomized trial for treatment of
morbid obesity. Ann Surg 1999; 230: 800–805.
43 Buckwalter JA. Clinical trial of jejunoileal and gastric bypass for
the treatment of morbid obesity: four-year progress report. Am
Surg 1980; 46: 377–381.
44 Buckwalter JA, Mason EE, Payne JH. A prospective comparison of
the jejunoileal and gastric bypass operations for morbid obesity.
World J Surg 1977; 1: 757–768.
45 Andersen T, Backer OG, Astrup A, Quaade F. Horizontal or vertical
banded gastroplasty after pretreatment with very-low-calorie
formula diet: a randomized trial. Int J Obes Relat Metab Disord
1987; 11: 295–304.
46 Laws HL, Piantadosi S. Superior gastric reduction procedure for
morbid obesity: a prospective, randomized trial. Ann of Surg 1981;
193: 334–40.
47 Naslund I. The size of the gastric outlet and the outcome of
surgery for obesity. Acta Chir Scand 1986; 152: 205–210.
48 Naslund I, Wickbom G, Christoffersson E, Agren G. A prospective
randomized comparison of gastric bypass and gastroplasty.
Complications and early results. Acta Chir Scand 1986; 152:
681–689.
49 Naslund I. Gastric bypass versus gastroplasty. A prospective study
of differences in two surgical procedures for morbid obesity. Acta
Chir Scand Suppl 1987; 536: 1–60.
50 Naslund I, Beckman KW. Gastric emptying rate after gastric
bypass and gastroplasty. Scand J Gastroentero 1987; 22: 193–201.
51 Naslund I, Hallgren P, Sjostrom L. Fat cell weight and number
before and after gastric surgery for morbid obesity in women. Int J
Obes Relat Metab Disord 1988; 12: 191–197.
52 Naslund I, Jarnmark I, Andersson H. Dietary intake before and
after gastric bypass and gastroplasty for morbid obesity in
women. Int J Obes Relat Metab Disord 1988; 12: 503–513.
53 Hall JC, Watts JM, O’Brien PE, Dunstan RE, Walsh JF, Slavotinek
AH, Elmslie RG. Gastric surgery for morbid obesity. The Adelaide
Study. Ann Surg 1990; 211: 419–427.
54 Nguyen NT, Goldman C, Rosenquist CJ, Arango A, Cole CJ,
Lee SJ, Wolfe BM. Laparoscopic versus open gastric bypass: a
randomized study of outcomes, quality of life, and costs. Ann Surg
2001; 234: 279–289.
55 Sjostrom L, Narbro K, Sjostrom D. Costs and benefits when
treating obesity. Int J Obes Relat Metab Disord 1995; 19: S9–S12.
56 Martin LF, Tan TL, Horn JR, Bixler EO, Kauffman GL, Becker DA,
Hunter SM. Comparison of the costs associated with medical and
surgical treatment of obesity. Surgery 1995; 118: 599–606.
57 Chua TY, Mendiola RM. Laparoscopic vertical banded
gastroplasty: the Milwaukee experience. Obes Surg 1995; 5: 77–80.
58 Anonymous. Gastrointestinal Surgery for Severe Obesity.
9[1]. NIH Consens Dev Conf Consens Statement (March 25–27).
1991.
59 Jung RT, Cuschieri A. Obese patients. In: Cuschieri A, Steele RJC,
Moosa AR (eds). Essential surgical practice–Vol 1, pp 227–240.
Butterworth Heinemann: London: 2000. 4th edn.
60 NHS Centre for Reviews and Dissemination. Undertaking Systematic Reviews of Research on Effectiveness. CRD’s Guidance for those
Carrying Out or Commissioning Reviews. CRD Report Number, 42nd
Edition. University of York: York; 2001.
61 MacLean LD, Rhode BM, Forse RA. A gastroplasty that avoids
stapling in continuity. Surgery 1993; 113: 380–388.
62 Williams R, Van Gaal L, Lucioni C. Assessing the impact of
complications on the costs of Type II diabetes. Diabetologia 2002;
45: S13–S17.
International Journal of Obesity