What follows may seem like TMI, but it shows you how skewed things can be just be looking at things statistically, and the surgeons ask, 'What is the real
answer here?" I don't know - we're asking you.
-B
________________________________________________________________________________
Author: Jacquelyn K. Beals, PhD -
http://www.medscape.com/viewarticle/576331?sssdmh=dm1.361387&src=nldne
June 19th, 2008
A study comparing the efficacy of laparoscopic adjustable gastric
band (LAGB) treatment with laparoscopic Roux-en-Y gastric bypass
(LRYGB) in terms of loss of excess body weight found that the treatment
outcomes differed significantly when failures were included but not
when failures were excluded. Failures included explantation of LAGB,
reversal of LRYGB, or conversion of either treatment to another
bariatric procedure.
Presented here at the American Society for Metabolic & Bariatric
Surgery 25th Annual Meeting, the study analyzed data from all patients
(N = 1280) who received LAGB (n = 576) or LRYGB (n = 704) as their
primary treatment during a period of 3 years, 7 months. Age and sex
distribution were equivalent in the 2 groups. Average body mass indexes
were 45.6 ± 0.26 kg/m 2 (LAGB) and 47.7 ± 0.28 kg/m 2 (LRYGB) ( P < .001).
Medscape General Surgery spoke with coauthor Richard S.
Flint, MD, a fellow in the group of David B. Lautz, MD, director of
bariatric surgery, Brigham & Women's Hospital, Harvard Medical
School, Boston, Massachusetts, who presented the study.
"You've got some studies saying that the bypass is more effective.
However, the more recent evidence is saying that the band is just as
effective as a bypass," said Dr. Flint. "And considering it has less
perioperative risk, that has quite a significant influence on what
operation a patient may choose. So what we're trying to identify is
what the real answer is here."
The study assessed excess body weight loss (EBWL) 1, 2, and 3 years
after each procedure and analyzed the effect of carrying forward the
final weight loss data of patients who dropped out of the study. At 3
years' follow-up, the percentage EBWL for the 2 treatments appeared to
be converging when failures were excluded ( P = .059). With
failures included, percentage EBWL for each treatment stabilized after
1 year, and mean percentage EBWL at 3 years was 73.3 in the LRYGB group
vs 37.0 in the LAGB group ( P < .001).
A second part of the study increased follow-up and used statistical
modeling to deal with missing data. In this analysis, the percentage
EBWL achieved with LYRGB was significantly greater than for LAGB and
was maintained over time.
Investigators concluded that proper handling of missing data,
including treatment failures, is necessary when comparing bariatric
procedures. "I think what we've shown in our data is that if you don't
handle the missing data and treatment failures correctly, then you can
actually get a skewed influence," said Dr. Flint. "And telling a
patient that they're getting the same result as a bypass when they're
not actually getting the same result as a bypass...they may be going
and unwittingly get discouraged. And that may jeopardize the band's
efficacy anyway," he said.
"No one can accurately predict what operation suits what patient....
[T]herefore, it's really left to the patient to decide," noted Dr.
Flint. "It's very important that you give them accurate facts. If
you've got proponents of 1 operation saying, well, this is the only
operation to do, then you're not giving the patient a fair go."
Victor F. Garcia, MD, a pediatric surgeon, director of Trauma
Services at Cincinnati Children's Hospital Medical Center Trauma
Services, and associate surgical director for the Cincinnati Children's
Comprehensive Weight Management Center, Ohio, discussed the study
following Dr. Flint's presentation.
"I think this is an incredibly important study of seminal
observations being made on patients lost to follow-up," noted Dr.
Garcia. Focusing on the challenge of maintaining high levels of
follow-up, he asked: "How can we be confident, then, that those lost to
follow-up...do not differ from those who return for follow-up?....
[T]he question is, what can you offer them?"
Dr. Garcia mentioned 2 "perhaps controversial approaches" — public
performance reporting or compensation for patients who follow-up. But
"how does [this] stipulate or consolidate problems that patients
already have?" Dr. Garcia asked.
Dr. Flint concluded: "What we're trying to say is, 'What is the real
answer here?' What happens to those treatments in the patients who
fail, and how does that influence the result? What we're trying to say
is that it does significantly influence the results."
Dr. Flint and Dr. Garcia have disclosed no relevant financial relationships.
American Society for Metabolic & Bariatric Surgery 25th Annual Meeting: Abstract PL-13. Presented June 18, 2008.
What follows may seem like TMI, but it shows you how skewed things can be just be looking at things statistically, and the surgeons ask, 'What is the real answer here?" I don't know - we're asking you.
-B
________________________________________________________________________________
Author: Jacquelyn K. Beals, PhD -
http://www.medscape.com/viewarticle/576331?sssdmh=dm1.361387&src=nldne
June 19th, 2008
A study comparing the efficacy of laparoscopic adjustable gastric band (LAGB) treatment with laparoscopic Roux-en-Y gastric bypass (LRYGB) in terms of loss of excess body weight found that the treatment outcomes differed significantly when failures were included but not when failures were excluded. Failures included explantation of LAGB, reversal of LRYGB, or conversion of either treatment to another bariatric procedure.
Presented here at the American Society for Metabolic & Bariatric Surgery 25th Annual Meeting, the study analyzed data from all patients (N = 1280) who received LAGB (n = 576) or LRYGB (n = 704) as their primary treatment during a period of 3 years, 7 months. Age and sex distribution were equivalent in the 2 groups. Average body mass indexes were 45.6 ± 0.26 kg/m 2 (LAGB) and 47.7 ± 0.28 kg/m 2 (LRYGB) ( P < .001).
Medscape General Surgery spoke with coauthor Richard S. Flint, MD, a fellow in the group of David B. Lautz, MD, director of bariatric surgery, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts, who presented the study.
"You've got some studies saying that the bypass is more effective. However, the more recent evidence is saying that the band is just as effective as a bypass," said Dr. Flint. "And considering it has less perioperative risk, that has quite a significant influence on what operation a patient may choose. So what we're trying to identify is what the real answer is here."
The study assessed excess body weight loss (EBWL) 1, 2, and 3 years after each procedure and analyzed the effect of carrying forward the final weight loss data of patients who dropped out of the study. At 3 years' follow-up, the percentage EBWL for the 2 treatments appeared to be converging when failures were excluded ( P = .059). With failures included, percentage EBWL for each treatment stabilized after 1 year, and mean percentage EBWL at 3 years was 73.3 in the LRYGB group vs 37.0 in the LAGB group ( P < .001).
A second part of the study increased follow-up and used statistical modeling to deal with missing data. In this analysis, the percentage EBWL achieved with LYRGB was significantly greater than for LAGB and was maintained over time.
Investigators concluded that proper handling of missing data, including treatment failures, is necessary when comparing bariatric procedures. "I think what we've shown in our data is that if you don't handle the missing data and treatment failures correctly, then you can actually get a skewed influence," said Dr. Flint. "And telling a patient that they're getting the same result as a bypass when they're not actually getting the same result as a bypass...they may be going and unwittingly get discouraged. And that may jeopardize the band's efficacy anyway," he said.
"No one can accurately predict what operation suits what patient.... [T]herefore, it's really left to the patient to decide," noted Dr. Flint. "It's very important that you give them accurate facts. If you've got proponents of 1 operation saying, well, this is the only operation to do, then you're not giving the patient a fair go."
Victor F. Garcia, MD, a pediatric surgeon, director of Trauma Services at Cincinnati Children's Hospital Medical Center Trauma Services, and associate surgical director for the Cincinnati Children's Comprehensive Weight Management Center, Ohio, discussed the study following Dr. Flint's presentation.
"I think this is an incredibly important study of seminal observations being made on patients lost to follow-up," noted Dr. Garcia. Focusing on the challenge of maintaining high levels of follow-up, he asked: "How can we be confident, then, that those lost to follow-up...do not differ from those who return for follow-up?.... [T]he question is, what can you offer them?"
Dr. Garcia mentioned 2 "perhaps controversial approaches" — public performance reporting or compensation for patients who follow-up. But "how does [this] stipulate or consolidate problems that patients already have?" Dr. Garcia asked.
Dr. Flint concluded: "What we're trying to say is, 'What is the real answer here?' What happens to those treatments in the patients who fail, and how does that influence the result? What we're trying to say is that it does significantly influence the results."
Dr. Flint and Dr. Garcia have disclosed no relevant financial relationships.
American Society for Metabolic & Bariatric Surgery 25th Annual Meeting: Abstract PL-13. Presented June 18, 2008.