Thanks, Michael
Can you tell how often your recommendations in fact differed
from the ACCP guidelines? That would be very interesting to learn.
Best
ben
From: [log in to unmask]
[mailto:[log in to unmask]]
Sent: Wednesday, September 30, 2009 1:44 PM
To: [log in to unmask]; Djulbegovic, Benjamin
Subject: Re: Reliable, Relevant Information About VTE Prophylaxis in THR
AND TKR Surgery and More
Ben, the
answer to your question about the ACCP VTE prophylaxis guidelines is
yes--they do contain evidence with major threats to validity (fatal
flaws). For example, the ACCP guidelines in their evaluation of
enoxaparin versus warfarin, included some non-blinded trials, trials that
did not present baseline characteristics of the groups or information about
concealment of allocation; some lacked information regarding
co-interventions and there were other problems. Our group chose to exclude
studies with high-risk of bias.
Year after
year, as we assess the evidence supporting guideline recommendations by various
groups, we see guideline recommendations based on conclusions
resulting from low quality studies. (We also see many systematic reviews that
include low quality studies).
We are not
alone. As recently pointed out by Bangalore 2008, the ACC/AHA guidelines on
perioperative assessment recommend perioperative beta blockers for non-cardiac
surgery. However in the meta-analysis of 33 trials (12,306
patients) only 13 trials were rated as having low risk of bias (i.e.,
adequate generation of the allocation sequence, allocation concealment,
binding of patients, personnel and those assessing outcomes) with the
rest classified as being at high risk of bias. Bangalore et al. argue that,
because of the increased risk of stroke, bradycardia and hypotension, beta
blockers should not be routinely used for perioperative treatment of patients
undergoing non-cardiac surgery unless patients are already taking them for
clinically indicated reasons (heart failure, coronary artery disease, previous
myocardial infarction). Finally they conclude that the ACC/AHA guidelines
committee should soften their stance on perioperative beta blockade until
definitive evidence shows clear benefit. They also conclude that use of
perioperative beta blockade as a performance measure, when there is no robust
evidence for improved outcome, is inappropriate. (Bangalore S, Wetterslev J,
Pranesh S, Sawhney S, Gluud C, Messerli FH. Perioperative Beta blockers in
patients having non-cardiac surgery: a meta-analysis. Lancet 2008; published
online Nov 11. DOI:10.1016/ S0140-6736(08)61560-3.)
Others have
reviewed the quality of evidence contained in national guidelines. In one
review of 431 guidelines produced by US medical specialty societies, reviewers
found that 82% did not apply explicit criteria to grade evidence, 87% did not
report whether a systematic search of the literature was performed and 67% did
not describe the type of professionals involved in the development of the
guideline. (Grilli R, Magrini N, Penna A, Mura G, Liberati A. Practice
guidelines developed by specialty societies: the need for a critical appraisal.
Lancet. 2000 Jan 8;355(9198):103-6.)
More
recently, Tricoci et al reviewed ACC/AHA practice guidelines issued from 1984
to September 2008. Evaluation of the 16 current guidelines that reported
levels of evidence revealed that only 314 recommendations of 2711 were
classified as level of evidence A (median, 11%), whereas 1246 (median, 48%)
were level of evidence C. Only 245 of 1305 class I recommendations had level of
evidence A (median, 19%). Tricoci et al. conclude that practice guidelines are
largely developed from lower levels of evidence or expert opinion. (Tricoci P,
Allen JM, Kramer JM, Califf RM, Smith SC Jr. Scientific evidence underlying the
ACC/AHA clinical practice guidelines. JAMA. 2009 Feb 25;301(8):831-41.)
We were
hoping to find a valid, clinically useful evidence synthesis when we started
our review of VTE prophylaxis in total hip and total knee replacement surgery.
We did not find a reliable secondary source, and we, therefore, did our own
review based on widely accepted criteria for validity (e.g., the Cochrane
Handbook). You can read more details about our project in an interview with the
team leader at
http://www.medicalleaders.org/mlInterview_index.htm#ChingKaren090928
Hope this
is helpful. Thanks, Mike
Michael E Stuart MD
President & Medical Director, Delfini Group
Clinical Asst Professor, UW School of Medicine
6831 31st Ave N.E.
Seattle, Washington 98115
206-854-3680 Mobile Phone
206-527-6146 Home Office
[log in to unmask]
www.delfini.org
On Tue Sep 29 12:28 , "Djulbegovic, Benjamin" sent:
I
am surprised by your statement "Current national guidelines are
conflicting and include fatally flawed evidence". As I am sure you must be
aware of widely popular EBM ANTITHROMBOTIC
AND THROMBOLYTIC THERAPY, 8TH ED: ACCP GUIDELINES (see http://www.chestjournal.org/content/133/6_suppl).
Are these guidelines flawed?
We
are especially pleased this month to be able to provide you with free access to
some very helpful and important new information. In addition to an
inspiring interview with practical tips from EBM visionary, Dr. Tim Young about
how patients deserve better and our suggestions for committee member
considerations when reviewing interventions as part of a Pharmacy &
Therapeutics Committee or a Medical Technology Assessment Committee, we are
very proud to jointly make available, with Kaiser Permanente Hawaii, some new
and important work —
Clinical
Practice Guideline & Decision Support for Venous Thromboembolism (VTE)
Prophylaxis for Total Hip and Total Knee Replacement Surgery
In
the summer of 2008, a group of KPHI clinicians and other stakeholders formed a
working group, along with us, to address the significant uncertainty around
thromboembolism or deep vein thromboembolism (DVT) prophylaxis for hip and knee
replacement surgery.
This
was very significant work as the risk of VTE in total hip replacement and
total knee replacement surgery without VTE prophylaxis is frighteningly high
with reported figures from 41% to 85%. Current
national guidelines are conflicting and include fatally flawed evidence.
Not
only can you access the guideline and decision support including a clinician
1-pager and a patient messaging script, you can also read about the project and
what is significant about this work. Evidence-based
quality improvements of this caliber are doable. Many of you too can do
projects like these — successfully and efficiently.
We
are grateful to all members of the team and to medical leader, Dr. Grant Okawa,
for his vision and support, and we are especially grateful to Dr. Karen Ching
for her incredible efforts, her wisdom, her good humor and her
leadership. Karen talks
with us about important elements contributing to the success of the project at www.medicalleaders.org.
And
not least, we always have new discoveries and learnings from working with the
evidence. Our work on this
project resulted in challenges for validity detectives which we report on at
the DelfiniClick â„¢:
"Advanced
Concepts: Can Useful Information Be Obtained From Studies With Significant
Threats To Validity? A Case Study of Missing Data Points in Venous
Thromboembolism (VTE) Prevention Studies"
You
can access everything new here: http://www.delfini.org/delfiniNew.htm.
Happy
Autumn! Sheri & Mike
Sheri
Strite
Principal & Managing Partner
Delfini Group, LLC
3961 NE 10th Ave
Portland, OR 97212-1222
Email: [log in to unmask],'','','')"
target="_blank">[log in to unmask]
Phone: 503-288-5154
www.delfini.org
www.medicalleaders.org & www.pharmacyleaders.org
Michael E Stuart MD
President & Medical Director, Delfini Group
Clinical Asst Professor, UW School of Medicine
6831 31st Ave N.E.
Seattle, Washington 98115
206-854-3680 Mobile Phone
206-527-6146 Home Office
[log in to unmask]
www.delfini.org