Gastric bypass as treatment for obesity: trends, characteristics, and complications.
ABSTRACT This paper describes national trends in gastric bypass procedures from 1998 through 2003 and explores the demographic and health profile of those who receive this procedure. Short-term outcomes such as length of stay and in-hospital complication rates are also examined.
Data on obese hospital inpatients who had gastric bypass were obtained from the 1998 to 2003 National Hospital Discharge Survey. Gastric bypass was reported for an estimated 288,000 discharges during the 6-year study period. Trends within the 6-year period were tested using weighted regression. Characteristics of gastric bypass patients were compared with those of other inpatients using a chi(2) test of independence and the two-sided t test.
The estimated number of hospital discharges with gastric bypass increased significantly, from 14,000 in 1998 to 108,000 in 2003. During this period, the average length of stay declined by 56% from 7.2 to 3.2 days. Gastric bypass patients were primarily women (84%), 25 to 54 years of age (82%), and privately insured (76%). A 1 in 10 complication rate was found for discharges with gastric bypass.
Gastric bypass procedures in the United States have increased rapidly since 1998, whereas the average hospital stay has decreased. The decreasing length of stay needs to be evaluated in conjunction with potential complication rates and the permanent change in anatomy and lifestyle that must accompany this procedure. Monitoring trends in use of this procedure is important, especially if reimbursement policies change and the epidemic of obesity continues.
- SourceAvailable from: Demetrios Moris[Show abstract] [Hide abstract]
ABSTRACT: Secondary hyperoxaluria is a multifactorial disease affecting several organs and tissues, among which stand native and transplanted kidneys. Nephrocalcinosis and nephrolithiasis may lead to renal insufficiency. Patients suffering from secondary hyperoxaluria, should be promptly identified and appropriately treated, so that less renal damage occur. The aim of this review is to underline the causes of hyperoxaluria and the related pathophysiologic mechanisms, which are involved, along with the description of seven cases of irreversible renal graft injury due to secondary hyperoxaluria.Transplantation Reviews. 01/2014;
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ABSTRACT: Cognitive dysfunction is associated with reduced postoperative weight loss up to 2 years following surgery, though the role of cognition at more extended follow-up is not yet understood. Thirty-six months following bariatric surgery, we retrospectively compared obese and non-obese patients on 12-week postoperative cognitive performance. We hypothesized that early postoperative cognitive dysfunction would predict higher body mass index (BMI) and lower percent weight loss (%WL) in the total sample at 36 month follow-up. Fifty-five individuals undergoing bariatric surgery completed cognitive testing at preoperative baseline and serial postoperative timepoints, including 12 weeks and 36 months. Cognitive test scores were normed for demographic variables. Percent weight loss (%WL) and body mass index (BMI) were calculated at 36-month follow-up. Adjusting for gender, baseline cognitive function, and 12-week %WL, 12-week global cognitive test performance predicted 36 month postoperative %WL and BMI. Partial correlations revealed recognition memory, working memory, and generativity were most strongly related to weight loss. Cognitive function shortly after bariatric surgery is closely linked to extended postoperative weight loss at 36 months. Further work is necessary to clarify mechanisms underlying the relationship between weight loss, durability, and cognitive function, including contribution of adherence, as this may ultimately help identify individuals in need of tailored interventions to optimize postoperative weight loss.Obesity Surgery 02/2014; · 3.10 Impact Factor
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ABSTRACT: Our study investigated how demographic, health, and behavioral factors interacted to affect weight outcomes in bariatric patients. Roux-en-Y gastric bypass (RYGB) patients who were non-Hispanic black, Hispanic, or non-Hispanic white race/ethnicity, had no revisions to their RYGB during 2004-2009, and had at least 1 year of follow-up data for body weight after surgery (n = 860) were surveyed by phone about their health and behaviors. The main outcomes of interest were percent excess weight loss and percent of initial weight lost. Participants were 47 ± 11 years old, 54 % non-Hispanic white, 25 % Hispanic, and 21 % non-Hispanic black, 82 % female, 60 % married, 82 % had some college education, and 47 % had an annual income between $35,000 and $80,000. At the time of surgery, patients had lost 50 ± 29 % of their excess weight and had achieved 24 ± 15 % initial weight lost after an average of 54 months of follow-up. After accounting for weight at the time of surgery, demographics, and self-reported health and behavior, non-Hispanic black men had significantly greater weight loss compared to non-Hispanic white men (p < .05). There were no differences between racial/ethnic groups of women in weight outcomes. Percent excess weight loss was related to greater diet soda intake, and percent initial weight lost was related to greater water intake. Independent of health status and lifestyle behaviors, age, and weight at the time of surgery, race/ethnicity, gender, and diet soda and water intake were the strongest predictors of weight outcomes after RYGB surgery.Obesity Surgery 05/2014; · 3.10 Impact Factor
Risk Factors and Chronic Disease
Gastric Bypass as Treatment for Obesity:
Trends, Characteristics, and Complications
Judith A. Shinogle, Maria F. Owings, and Lola Jean Kozak
SHINOGLE, JUDITH A., MARIA F. OWINGS, AND
LOLA JEAN KOZAK. Gastric bypass as treatment for
obesity: trends, characteristics, and complications. Obes
Objective: This paper describes national trends in gastric
bypass procedures from 1998 through 2003 and explores the
demographic and health profile of those who receive this
procedure. Short-term outcomes such as length of stay and
in-hospital complication rates are also examined.
Research Methods and Procedures: Data on obese hospital
inpatients who had gastric bypass were obtained from the
1998 to 2003 National Hospital Discharge Survey. Gastric
bypass was reported for an estimated 288,000 discharges
during the 6-year study period. Trends within the 6-year
period were tested using weighted regression. Characteris-
tics of gastric bypass patients were compared with those of
other inpatients using a ?2test of independence and the
two-sided t test.
Results: The estimated number of hospital discharges with
gastric bypass increased significantly, from 14,000 in 1998
to 108,000 in 2003. During this period, the average length of
stay declined by 56% from 7.2 to 3.2 days. Gastric bypass
patients were primarily women (84%), 25 to 54 years of age
(82%), and privately insured (76%). A 1 in 10 complication
rate was found for discharges with gastric bypass.
Discussion: Gastric bypass procedures in the United States
have increased rapidly since 1998, whereas the average
hospital stay has decreased. The decreasing length of stay
needs to be evaluated in conjunction with potential compli-
cation rates and the permanent change in anatomy and
lifestyle that must accompany this procedure. Monitoring
trends in use of this procedure is important, especially if
reimbursement policies change and the epidemic of obesity
Key words: National Hospital Discharge Survey, length
of stay, payment source, comorbidities, race
Obesity is currently a pressing health issue, with 30% of
adults considered obese in 1999 to 2000 (1). This is a
significant increase from the 23% found to be obese in 1988
to 1994 (1,2). Obesity is defined as having a BMI (weight in
kilograms divided by the square of height in meters) of
?30. Even more troubling than the overall obesity growth
rate is the significant increase in morbid obesity (defined as
BMI ? 40) during this same time period, from ?3% to 5%
Bariatric surgical procedures are among the few current
treatments to produce sustained weight loss (3). The most
common surgical procedures performed include adjustable
gastric banding and Roux-en-Y gastric bypass. A recent
meta-analysis found that bariatric procedures not only cause
significant weight loss but also lead to improvement in
many associated conditions such as diabetes, hypertension,
hyperlipidemia, and obstructive sleep apnea (4).
Gastric bypass involves creating a small stomach pouch
in the upper quadrant of the stomach using staples to per-
manently close the remaining area of the stomach. This
pouch is then connected to the small bowel. The stomach
volume is decreased to ?30 mL, which requires a perma-
nent change in eating habits. Continuing patient follow up
and adherence to a new dietary regimen are important
components to the success of this operation (5).
Gastric bypass has received increased publicity due to
famous celebrities discussing their weight loss (Today
Show’s Al Roker, American Idol’s Randy Johnson, and
singer Carnie Wilson), and most evidence points to de-
creased morbidity and mortality as a result of the procedure
(6,7). However, it is controversial as a means of cost savings
in health (8–11). In addition to the debate over costs, recent
reports of complications and deaths have raised concerns
about the safety of the procedure (4,12–14). To improve
Received for review February 18, 2005.
Accepted in final form September 28, 2005.
RTI International, National Center for Health Statistics, Centers for Disease Control and
Prevention, Washington, DC.
Address correspondence to Judith A. Shinogle, RTI International, 1615 M Street NW, Suite
740, Washington, DC 20036-3209.
Copyright © 2006 NAASO
2202OBESITY RESEARCH Vol. 13 No. 12 December 2005
outcomes and reduce complications and errors, an expert
panel on weight loss surgery provided recommended steps,
best practice, and clinical guidelines (15). At the same time,
the Centers for Medicare and Medicaid Services announced
that they will remove language from their regulations that
obesity is not a disease (16), leaving open the possibility
that Medicare may cover the cost of gastric bypass.
Using data from its members, the American Society of
Bariatric Surgery has estimated that the number of gastro-
intestinal surgical procedures for obesity grew from 16,000
in 1992 to 103,000 in 2003 (17). Pope et al. (18) examined
data from the Nationwide Inpatient Sample and found a
significant increase in the rate of gastric bypass between
1990 and 1997 from 2.7 to 6.3 per 100,000 adults and a
decline in the median length of stay from 5 to 4 days. They
also found that in 1997, 84% of gastric bypass patients were
women, the median age was 40 years, and 31% had one or
more comorbid conditions, although the mortality rate was
only 0.37 per 100 discharges.
Livingston and Ko (19) used the 2000 National Health
Interview Survey to determine the characteristics of the
population eligible for gastric bypass and compared these
results with the 2000 Healthcare Cost and Utility Project
data and the 2000 National Hospital Discharge Survey
(NHDS).1They found that although African Americans
accounted for 21% of all individuals eligible for bariatric
procedures, they made up only 9% of those undergoing
Using the 1996 through 2001 NHDS, Livingston (20)
examined in-hospital complication rates associated with
bariatric procedures. He found a clinically significant com-
plication rate of 10%. His research provided some informa-
tion regarding comorbidities and complications of dis-
charges who had this procedure, but was limited by small
The public health significance of obesity and the rapid
developments surrounding its surgical treatment point to the
need for more information about gastric bypass. Our re-
search explores current trends in gastric bypass, character-
istics of patients receiving gastric bypass, and complications
after gastric bypass. These data supply valuable information
for tracking use of this procedure and the patient population
it serves, evaluating the safety of gastric bypass, and pro-
viding baseline information before possible changes in
Medicare reimbursement policies.
Our study provides nationally representative estimates
from public data to compare with previous research in this
area. The results reported here also update and expand on
Pope’s (18) and Livingston’s (19,20) figures. We use more
recent data and include all age groups. Reports now show
that gastric bypass is being performed on persons under 18
years of age (21).
Research Methods and Procedures
Data for this analysis were from the 1998 to 2003 NHDS
conducted annually by the National Center for Health Sta-
tistics since 1965. The data were collected from a sample of
inpatient records obtained from a national probability sam-
ple of hospitals. Only general hospitals, children’s general
hospitals, or hospitals with an average length of stay of
fewer than 30 days for all patients were included in the
survey. Federal hospitals were excluded. During 1998 to
2003, an annual average of 448 hospitals participated in the
survey for an average response rate of 93%. These hospitals
provided information on ?316,000 sampled discharges per
year. The data could be analyzed only for 1998 and subse-
quent years because in earlier years, the annual number of
discharges with gastric bypass sampled in the survey was
too few to make reliable national estimates. A description of
the estimation process and other aspects of the survey’s
design and operation have been published (22).
Items collected in the NHDS include age, sex, and race of
the patient; expected principal source of payment and length
of stay for the hospitalization; geographic region of the
hospital; and up to seven diagnoses and four surgical or
non-surgical operations or procedures performed during the
hospitalization. Diagnoses and procedures are coded ac-
cording to the International Classification of Diseases,
Ninth Revision, Clinical Modification (ICD-9-CM) (23).
The NHDS does not collect information regarding height
and weight; therefore, discharges were included in this
analysis if they had a principal or secondary diagnosis of
obesity (ICD-9-CM code 278.0) and a high gastric bypass
(code 44.31) or other gastroenterostomy (code 44.39) per-
formed during the hospitalization. High gastric bypass is
defined as a procedure that connects the middle part of the
small intestine to the upper stomach, and the category
specifically includes Printen and Mason gastric bypass. A
variety of other bariatric procedures, such as gastric banding
and biliopancreatic diversion, may also have been coded as
44.31 or 44.39 because codes for other specific bariatric
procedures were not available during the period covered by
The obesity diagnostic code included both unspecified
(278.00) and morbid obesity (278.01). We limited our study
to those who were identified as obese to exclude patients
who received gastroenterostomies for other conditions such
as cancer, ulcers, and other stomach-related disorders. Only
about one-half of patients with gastroenterostomies (code
44.39) had an obesity diagnosis. In contrast, 98% of the
patients who had high gastric bypass (ICD-9-CM code
44.31) during 1998 to 2003 had obesity or morbid obesity as
1Nonstandard abbreviations: NHDS, National Hospital Discharge Survey; ICD-9-CM,
International Classification of Diseases, Ninth Revision, Clinical Modification.
Gastric Bypass as Treatment for Obesity, Shinogle, Owings, and Kozak
OBESITY RESEARCH Vol. 13 No. 12 December 20052203
a diagnosis. Unlike Pope (18), we included discharges for
all ages who met the selection criteria named above because
gastric bypass is being performed on younger patients (21).
To further understand the risks associated with gastric
bypass that were reported by Livingston (20), and to place
them into context with other procedures, complication rates
for discharges with gastric bypass were compared with
those for discharges with other surgical procedures. A dis-
charge with any ICD-9-CM diagnosis code 996 to 999 or
E87 was counted as having a complication.
Standard errors for the estimates were obtained using
SUDAAN software (24). Trends in annual discharge rates
and average lengths of stay during 1998 to 2003 were tested
using weighted least squares regression for complex surveys
(25). Data for the 6-year period were grouped to allow
reliable examination of characteristics of patients with gas-
tric bypass. Discharge rates for gastric bypass patients were
produced for sex, age, race, and regional groups to compare
demographic differences in use of this procedure. Rates
were calculated by dividing the estimated number of dis-
charges in each group by the midyear civilian resident
population for that group, expressed per 100,000 popula-
tion. The population estimates were obtained from the U.S.
Percentage distributions by sex, age, race, region, and
expected principal source of payment were compared to
examine how discharges receiving gastric bypass differed
from other hospital discharges. Contingency table analysis
was used for these comparisons, and significance was de-
termined by means of a ?2test of independence. Comor-
bidities were selected for analysis because a large number of
discharges reported the diagnosis or because the diagnosis
was of special interest in obesity research. Percentages of
gastric bypass discharges and other discharges with these
comorbidities were compared with a two-sided t test. Be-
cause multiple comparisons were made, the Bonferroni ad-
justment was used, with an overall level of significance set
Over the 6-year period studied, 2573 discharges had
ICD-9-CM codes indicating obesity and gastric bypass.
Sampled cases were weighted to produce national statistics
using multistage estimation procedures. This produced a
weighted national estimate of obese patients with gastric
bypass of 288,000.
The number of gastric bypass procedures has grown
significantly from an estimated 14,000 in 1998 to an esti-
mated 108,000 in 2003. The rate of gastric bypass per
100,000 population grew from 5.3 to 37.1 during the 6-year
period (Figure 1). At the same time, the average length of a
hospital stay for a gastric bypass discharge decreased 56%,
from 7.2 days in 1998 to 3.2 days in 2003 (Figure 2). The
average length of stay for all patients declined by only 6%
during this period, from 5.1 days in 1998 to 4.8 days in
During 1998 to 2003, patients receiving gastric bypass
had different characteristics than other inpatients. They
were more likely to be women (84% vs. 60% for non-gastric
bypass patients) and 25 to 54 years of age (82% vs. 34%).
They were also more likely than other discharges to have
private or other commercial insurance, including health
maintenance organizations and preferred provider organiza-
tions (76% vs. 36%), as the principal expected source of
payment (Table 1).
As reported in previous research, women had a higher
rate of gastric bypass discharges per 100,000 population
than men, 27.9 compared with 5.7 (Table 1). Gastric bypass
Figure 1: Discharge rate for obese inpatients with gastric bypass,
United States, 1998 to 2003.
Figure 2: Average length of stay in days for obese discharges with
gastric bypass and for all other discharges, United States, 1998 to
Gastric Bypass as Treatment for Obesity, Shinogle, Owings, and Kozak
2204OBESITY RESEARCH Vol. 13 No. 12 December 2005
discharge rates were higher for those 25 to 39 and 40 to 54
years old than for older or younger persons. The median age
for a gastric bypass patient was 42 years during 1998 to
2003. Gastric bypass rates were not significantly different
for black and white patients or across geographic regions.
Almost all obese patients who received gastric bypass
during 1998 to 2003 had a first listed diagnosis of morbid
obesity. They had an average of 3.7 diagnoses in addition to
morbid obesity. Comorbidites for obese patients receiving
gastric bypass during 1998 to 2003 are shown in Figure 3.
1998 through 2003
Characteristics of obese discharges who received gastric bypass and all other discharges, United States,
Obese discharges with gastric bypass
(N ? 288,000)
All other discharges
(N ? 196,493,000)
Under 25 years
25 to 39 years
40 to 54 years
55 years and over
Race not stated
Expected principal source
Source not stated
17.11.8 100.0* 100.0*
SE, standard error.
* Not applicable.
† Percentage distribution of gastric bypass discharges significantly different from distribution of other discharges, ?2test of independence
significant at p ? 0.001.
‡ Denominators not available.
§ Estimate not reliable; relative SE greater than 30%.
¶ Includes HMOs and PPOs, BlueCross BlueShield, and other private or commercial insurance.
? Includes workers compensation, other government sources, self-pay, no charge, and other unspecified sources.
Gastric Bypass as Treatment for Obesity, Shinogle, Owings, and Kozak
OBESITY RESEARCH Vol. 13 No. 12 December 20052205
Essential hypertension was reported for 44% of these pa-
tients; 33% had joint diseases and related disorders, includ-
ing osteoarthritis; esophageal reflux was mentioned for 28%
of gastric bypass discharges; sleep apnea for 24%; and
diabetes for 20%. Disorders of lipid metabolism, depres-
sion, and asthma were reported for 10% or more of gastric
bypass discharges. Two-thirds of the gastric bypass patients
had two or more of these comorbidities. For comparison,
percentages of discharges that did not have gastric bypass
are also shown in Figure 3. The percentage with each
obesity-related comorbidity was significantly higher for
gastric bypass discharges than for all other discharges.
The outcome of gastric bypass cannot be fully measured
with hospitalization data, but we can examine complications
that arise in the hospital during the operation and the im-
mediate postoperative period. One of every 10 discharges
with gastric bypass had a medical or surgical complication
reported during their hospitalization. These complications
included conditions such as intestinal obstruction, acciden-
tal puncture or laceration, aspiration pneumonia, hemor-
rhage, postoperative infection, and cardiac complications.
Figure 4 presents complication rates per 100 discharges
with selected surgical procedures. Also shown are rates for
discharges who received gastric bypass and for all those
who received surgical procedures. The complication rate for
gastric bypass patients was similar to that for all discharges
with surgical procedures, ?10%. It was not significantly
different from rates for specific procedures such as prosta-
tectomy, appendectomy, hip or knee replacement, abdomi-
nal hysterectomy, or cholecystectomy but was lower than
rates for procedures such as repair of hernia, partial excision
of large intestine, and coronary artery bypass graft.
Surgical complications tend to increase with age (26);
thus, the complication rates for gastric bypass and other
procedures for those ?55 years of age were also analyzed.
The majority of the gastric bypass discharges (88%) were
under age 55 in 1998 to 2003, but only one-half of dis-
charges with other surgical procedures fell into this age
category. This analysis revealed a similar pattern as seen in
comparing the overall rates. Two exceptions were that the
gastric bypass complication rate was higher than complica-
tion rates for appendectomy or knee replacement in this age
group (data available from authors).
As seen in previous research, our data showed that the
number and rate of gastric bypass procedures are increasing.
Data from the NHDS estimate a median age of 42 for 1998
to 2003, similar to Pope et al.’s (18) median age of 40. In
addition, the percentage of gastric bypass discharges that
were women was almost identical in this and Pope’s anal-
yses. Our study found that three-quarters of the gastric
bypass procedures were paid, in part or in full, by private
health insurance, as was found in previous research. The
trend in private health insurance coverage should be mon-
itored because recent reports suggest a re-examination of
coverage by private health insurers (27). Nevertheless,
trends in the demographics and financing of gastric bypass
have been generally stable.
Similar to Livingston and Ko (19), we found a discrep-
ancy between the distribution of obesity in the population
and the profile of patients who received gastric bypass.
From 1999 to 2000, among the non-Hispanic population,
15% of black women were classified as extremely obese
compared with only 5% of white women (1). (For men, the
estimated percentage of extremely obese black men was not
reliable, but 3% of white men were extremely obese.) How-
ever, we found no significant difference in rates of gastric
bypass per 100,000 population by race. We also examined
the rates by race separately for men and women and again
Figure 3: Percentage of obese discharges with and without gastric
bypass surgery with selected comorbidities, United States, 1998 to
Figure 4: Rate of discharges with complications for selected types
of surgery, United States, 1998 to 2003.
Gastric Bypass as Treatment for Obesity, Shinogle, Owings, and Kozak
2206 OBESITY RESEARCH Vol. 13 No. 12 December 2005