Transcript Welcome [www.chnri.org]

Evidence Based Medicine
– Introduction
&
Information Resources
Dr. Suman Bhusan Bhattacharyya
MBBS, ADHA, MBA
&
http://www.cebm.net/
An Evaluation
•
•
•
•
•
What?
Why?
Where?
How?
Pain areas…
Evidence Based Medicine
– What?
• Widely credited to have been coined by Dr. David Eddy of
Kaiser Permanente
• It is believed that its philosophical base dates back to the
sceptics of post-revolutionary France (Xavier Bichat,
Pierre Louis, François Magendie)
• May have origins in China, B.C.
• The conscientious, explicit and judicious use of current
best evidence in making clinical decisions about the care
of individual patients (Dr. David Sackett, 1996)
Evidence Based Medicine
- When?
• There is evidence that something works, is
good and benefits the patient, do it
• There is evidence that something does not
work, is harmful, does not benefit the patient,
do not do it
• There is insufficient evidence, be conservative,
relying on individual clinician expertise
Evidence Based Practice
- What?
Any practice that applies up-to-date
information from relevant and valid research
about the usefulness of various diagnostic
tests or the predictive power of prognostic
factors or the beneficence of a particular
treatment method across healthcare,
including education, practice management
and health economics, it is said to be EBMenabled.
Evidence Based Enablement,
but…
Mere application of evidence based
medicine is in itself simply not good enough.
The end results need to be validated. This is
done by performing outcomes analysis,
preferably on a continuous basis
Evidence Based Practice
– Why?
• The old way of depending on a combination of
informed guesswork, unsystematic observation,
common sense, the consensus views of clinical
experts, and the so-called “standard and accepted
practice”, meaning the treatments and procedures
used by most other clinicians in a local community –
was fine, but with the addition of enormous
amounts of information every day, things are
threatening to “get out of control”.
• So, is this way “the only way”?
The Pain Areas…
•
•
•
•
•
•
27 Kg of guidelines,
3000+ new papers per day,
1000 new Medline articles,
46 randomized clinical trials
The number of biomedical journals alone doubling since 1970.
Average workload for a clinician of anything between 100 to 200
consultations a week resulting in 5000 to 10000 per year.
• Add to it the difficulty of relying solely on experience while using 2
million pieces of information all stored in ones memory, ever
increasing pressures to provide value-for-money services, raised
patient demands and expectations, pressures due to a myriad of
obtrusive and mostly confusing regulatory compliances, and rapidly
altering business demands.
• Hmmm…
The Pain Areas… [Contd.]
Every encounter with a patient identifies
gaps in our knowledge about the etiology,
diagnosis, prognosis, or therapy of their
illness. Recent research reveals that even as
seasoned clinicians we generate about five
knowledge “needs” for every in-patient
encounter, and two “needs” for every three
out-patients encounters.
The Pain Areas…
a plausible answer
• To bridge these gaps and fulfill the “needs”, we
need to practice evidence based medicine, and
to evaluate the best evidence that evidence
based medicine is supposed to reveal we need to
perform outcomes analysis
• Practicing medicine based on best evidence in
the form of clinical protocols helps as a valid
legal cover in malpractice suits
Best Evidence…
• Current best evidence is up-to-date
information from relevant, valid research
about the effects of different forms of
healthcare, the potential for harm from
exposure to particular agents, the accuracy
of diagnostic tests, and the predictive
power of prognostic factors.
PICO
– well built clinical questions
Evidence Based Medicine
– How? The way of seven A’s…
Assess the patient
a clinical conundrum or question that arises out of the clinical examination
Ask the patient
the care provider needs to construct a well-built clinical question from the findings
in step 1
Access the information
the appropriate resources needs to be selected and searched for the answer to the
question framed in step 2
Appraise the evidence
the information gathered in step 3 needs to be critically appraised using the
various indices for its validity and applicability to the patient’s problems
Apply the findings
the validated evidence needs to be integrated with clinical expertise and patient
preferences and then applied as required
Assess the outcomes
the performance of the evidence with the patient needs to be evaluated
Add the knowledge
the information so gathered added to the clinician’s knowledge base for future
reference to best evidence in similar problems
Evidence Based Medicine
– The Types
• Diagnostic
– Here the importance of various
observations, value of diagnostic tests,
etc. are evaluated in ruling in or out a
diagnosis
• Treatment
– Here the value of a treatment method
or the necessity of a particular
medication or procedure is determined
Evidence Based Balance Sheet
An evidence based balance sheet is an
important tool that supports the
practice of evidence based medicine.
1. Examine the evidence that a treatment is
effective.
2. If so, then determine the magnitude of its
benefits, harms, and costs.
Evidence Based Balance Sheet
• Display in a compact form the evidence as
quantitative estimates of the effects of
alternative treatments on all the important
outcomes
• The decision-makers can more easily grasp
the consequences of the different options
they face.
• Specially useful for informed shared decisionmaking between physicians and patients.
Developing an Evidence Based Balance
Sheet – The 4 Main Steps
1. Identification of the alternative treatments that are
available to the patient
2. Identification of the health outcomes (i.e., the
outcomes that can be experienced by, and are
important to, the people who will receive the
treatments) that are affected by the treatments
3. Estimation of the probabilities or magnitudes of
each of the health outcomes, for each of the
alternative treatments
4. Displaying the information in a table
EBM Balance Sheet – An Example
One-year probabilities of outcomes associated with Alendronate 5 mg vs. no drug, for a 55-year-old averagerisk woman.
Item
No Drug
Drug
Difference
NNT
Hip fracture
.00046
.00032
.00014
7143
Wrist fracture
.00316
.00223
.00093
1078
Spine fracture
.00144
.00084
.0003
3322
Long-term benefits
0
?
?
?
Inconvenience
1
0
1
1
Gastric distress
30%
0
30%
3
Long-term Harms
0
?
?
?
Cost of drug
$0
$308
+$308
Expected cost of treatment
$220
$203
-$17
Net cost
$220
$511
+$291
Problems associated with Evidence
Based Practice
Problems
Solutions/Workarounds
Resources and commitments in terms of time and money
that needs to be delivered away from actual patient care
Evaluate against opportunity cost, follow-on and
abandonment option costs. Evidence based practice
wins hands down as a strategic investment
Finding and evaluating the evidence is costly in terms of
time
Use EPR
Lack of skills in computer use and locating evidence
Train personnel. This is not an issue with the
generation next.
Resources needed to acquire and maintain databases
Availability in electronic form and increased usage will
bring the prices down
Searching may only result in discovering gaps in medical
knowledge
One must seriously doubt our capabilities and
question our insecurities
Poor indexing may lead to frustration of futile literature
searches
Use online searches and make all literature available
searchable online
The quality and quantity of research mostly unknown
Use refined studies performed real-time using EPR
Demands a high degree of statistics knowledge
Use EPR that have the calculations as well as their
interpretations built-in
Viewed as a form of rationing
Evidence based medicine is about improving the
quality of patient care. It is just as likely to show that
effective interventions are underused as to show that
ineffective procedures are over-used
EBM in Clinical Protocols
• Clinical protocols need to be made based
on the current best evidence
• These protocols must undergo continuous
revalidation in order to continue to be
relevant according to the current best
evidence
• Protocols change according to triage
assessments and specialty – so they need
to be user and problem-specific
Evidence-Based
Information Resources
Push, Pull, Prompt
…ways to deal with
too much information
Evolution of EBM Info
PreEBM: Passive diffusion (“publish it and they
will come”)
Early EBM: Pull diffusion (“teach them to read
it and they will come”)
Current EBM: Push diffusion (“read it for them
and send it to them”)
Future EBM: Prompt diffusion (“read it for
them, connect it to their individual patients,
prompt them and their patients”)
Information in the Internet Age*
Information in the Internet age may be constrained by
a variant of Malthus’ law:
• The amount of information is growing exponentially,
but our attention is not.
• A wealth of information creates a poverty of
attention.
• The low cost of production of poor quality
information results in high quality information being
drowned out.
• The cost of finding specific information rises as the
amount of information increases.
*Coiera E. Information economics and the internet.
J Am Med Inform Assoc 2000;7:215-21.
The Slippery Slope
100%
r = -0.54
p<0.001
..
Choudhry, Fletcher and.Soumerai,
knowledge
Ann
Intern Med 2005;142:260-73
...
.
.
....
.
...
50%
of
current
-94% of 62 studies found decreasing ...
best care
....with
...tasks,
competence for at least some
..
increasing physician age.
....
0%
years since
graduation
The McMaster PLUS project
• only a tiny proportion of all research is “ready
for application”
• only a tiny fraction of the “ready” research is
“relevant” to the practice of a given clinician
• only a tiny proportion of the “relevant” research
for a given practitioner is “interesting” in the
sense of being something new, important, and
actionable.
Evidence-Based Journals
Critical Appraisal Filters
60,000 articles/yr
from 120 journals
~3,500 articles/yr
meet critical appraisal
and content criteria
(95% noise reduction)
McMaster PLUS Project
Clinical Relevancy Filter (MORE)
~3,500 articles/yr meet
critical appraisal
and content criteria
(95% noise reduction)
~25 articles/yr for
clinicians (99.95%
noise reduction)
~5-50 articles/yr for
authors of evidencebased clinical topic
reviews
McMaster Online Rating of Evidence: >6000 practicing clinicians
http://bmjupdates.mcmaster.ca
User End
• Users sign up according to discipline
• Users control relevance and flow
• Users can change disciplines at any time, and can sign up for
as many as they wish
• Users can search according to discipline – or not
• Users can access PubMed Clinical Queries
• (We can monitor individual use, if agreed)
Dear Dr. Haynes,
We want to alert you to NEW articles in the PLUS system.
These articles that have received very high relevancy and newsworthiness scores:
1. Brazg
R, et al. Effect of adding sitagliptin, a dipeptidyl peptidase-4 inhibitor, to metformin
on 24-h glycaemic control and beta-cell function in patients with type 2 diabetes. Diabetes
Obes Metab. 2007;9:186-93.
Rated by: IM/General (patients referred from
Primary Care)
Relevance: 5 of 7
Newsworthiness: 5 of 7
We hope that you will find these articles of value in your clinical practice.
Best wishes from the PLUS Team
CONCLUSIONS: In this 24-week study, oncedaily sitagliptin monotherapy improved glycemic
control in the fasting and postprandial states {vs
placebo}, improved measures of beta-cell
function, and was well tolerated in patients with
type 2 diabetes.
Medscape Best Evidence Alerts
Free at https://profreg.medscape.com/px/newsletter.do
The evolution of information resources
for evidence-based decisions Examples
Systems
Computerized decision
support
Summaries
Evidence-based
textbooks
Synopses
Evidence-based journal
abstracts
Systematic reviews
Syntheses
Original journal articles
Studies
Premier evidence resources
Systems: EMR with decision support
Summaries: Clinical Evidence, PIER,
UpToDate, Dynamed
Synopses: ACP Journal Club, EBM
Syntheses: via BMJUpdates+
Studies: via BMJUpdates+, PubMed
Clinical Queries
58 year old obese male with
…type 2 diabetes mellitus
…A1c 9% (elevated) on glyburide and
rosiglitazone, with metformin intolerance
…continuing to gain weight
…very reluctant to take insulin
Can the new ‘incretin therapies’ (eg,
exenatide, pramlintide or sitagliptin)
help?
For type 2 diabetes, what are the effects
Systems
good
and
bad
Summaries
Synopses
of incretin therapy?
Syntheses
Studies
Systems: no Computerized Decision Support
Summaries: in UTD, PIER, Dynamed, not CE
Synopses: sitagliptin in ACP JC
Syntheses: one for pramlintide in BMJUpdates+
Studies: exenatide, pramlintide, sitagliptin in UTD,
PIER, CE, BMJUpdates+; more on exenatide,
pramlintide and sitagliptin in Clinical Queries
Section updated June 2007
Comments on exenatide, pramlintide, sitagliptin, with
drug monographs for each
“Many questions remain unanswered regarding
clinical use and long-term outcomes with these
drugs.”
Januvia is approved for use by people with type 2 diabetes
US$5 adequately
per pill
that can't be controlled
with diet and exercise.
• Includes exenatide, pramlintide, and sitagliptin, with drug
monographs for each
• “Consider metformin as a first-line agent because it causes
less hypoglycemia and weight gain, along with possible
improvements in cardiovascular risk.”
• “Consider other oral agents, such as sulfonylureas,
thiazolidinediones, and DPP-IV inhibitors {sitagliptin}, as
reasonable first-line agents, although some are costly and
the long-term benefits of these drugs have not been well
studied.”
CONCLUSIONS: Incretin therapy offers an alternative
option to currently available hypoglycemic agents for
nonpregnant adults with type 2 diabetes, with modest
efficacy and a favorable weight-change profile.
Careful postmarketing surveillance for adverse
effects, especially among the DPP4 inhibitors, and
continued evaluation in longer-term studies and in
clinical practice are required to determine the role of
this new class among current pharmacotherapies for
type 2 diabetes.
Survey of traditional
textbooks of medicine
• Harrison’s Textbook – nothing
• Books@Ovid – nothing
• Kelley’s Textbook - nothing
My conclusions about exenatide,
pramlintide, sitagliptin
• Interesting new options for diabetes
• Not well studied (eg, no comparisons with
current best medications)
• Exenatide and pramlintide would likely be
out for this patient (injections)
• Sitagliptin is a possibility, but not until better
known options tried (acarbose, Avandamet,
repaglinide)
Finding evidence when you’re not
sure where to look
• TRIP
• SUMSEARCH
• CLINICAL QUERIES
(Pick One)
To keep up with evidence
Systems
Summaries
• Pull
Synopses
Syntheses
Studies
• Push
• Prompt…some labs and EMRs
with a credible evidencebased pedigree (Zynx)
Thank You!