Transcript PICO

PICOS
PICO
• P: Patient characteristics
• I: Intervention
• C: Control (alternative interventions)
• O: Outcomes
• (S): Study Design
How does bleaching affect patients who have
active caries and/or are considered high risk
for caries?
P
I
C
O
How does bleaching affect patients who have
active caries and/or are considered high risk
for caries?
P
I
patients who have active caries and/or are
considered high risk for caries
bleaching
C
Not specified
O
Not specified
For a patient with periodontitis, generalized
bone loss and deep pockets, does adding deep
cleaning + chlorhexidine rinse help obtain
better results ?
P
I
C
O
For a patient with periodontitis, generalized
bone loss and deep pockets, does adding deep
cleaning + chlorhexidine rinse help obtain
better results ?
P
patient with periodontitis, generalized bone
loss and deep pockets
I
deep cleaning + chlorhexidine rinse
C
Not specified
O
Not specified
In patients with a localized vestibular swelling
due to spread of an endodontic infection, is
incision and drainage alone an appropriate
treatment, or should the patient also be
prescribed an antibiotic?
P
I
C
O
In patients with a localized vestibular swelling
due to spread of an endodontic infection, is
incision and drainage alone an appropriate
treatment, or should the patient also be
described an antibiotic?
P
patients with a localized vestibular swelling
due to spread of an endodontic infection
I
I &D
C
I &D + antibiotic (which one?)
O
Not specified
Does the NTI (Nociceptive Trigeminal
Inhibition) device have an effect on migraine
incidence?
P
I
C
O
Does the NTI device have an effect on migraine
incidence?
P
Not specified
I
NTI
C
Not specified
O
Migraine incidence
Is topical fluoride effective?
P
I
C
O
Is topical fluoride effective?
P
Not specified
I
Topical fluoride
C
Not specified
O
Not specified
Is the zirconia reinforced ceramic crown a
reliable alternative to the traditional metalceramic crown when it comes to restoring
teeth?
P
I
C
O
Is the zirconia reinforced ceramic crown a
reliable alternative to the traditional metalceramic crown when it comes to restoring
teeth?
P
Not specified
I
zirconia reinforced ceramic crown
C
metal-ceramic crown
O
Not specified
PICOs
“A great deal of influence rests in
the hands of parties who control
the framing of a health issue”
“K.D. Brownell and K.E. Wagner, 2009”
Canto, 27, on a restricted diet, and Owen, 29, a control subject at the Wisconsin
National Primate Research Center in 2009. Wisconsin’s study concluded that calorie
restriction lengthened life, but a later study suggested the opposite.CreditJeff
Miller/University of Wisconsin-Madison
Doess a calorie-restricted diet increase longevity?
P
rhesus monkeys
I
zirconia reinforced ceramic crown
C1
“eat like the American population at large — as
much as they wanted of a not particularly healthy
diet, loaded with sucrose, and in which all foods
were laboratory purified”
“whole foods and were given fixed portions,
based on what they naturally ate before the study
started.”
Longevity
C2
O
Asking corporate sponsors to conduct pivotal
trials on their own products is like asking a
painter to judge his or her own painting so as to
receive an award. If a manufacturer can be
allowed to manipulate the system to create a
blockbuster product from an ineffective drug,
the temptation is hard to resist.
Vinay Prasad, MD
Adam Cifu, MD
John P. A. Ioannidis, MD, DSc
JAMA 2012
Smoking when compared to no smoking is
associated with an increased lung cancer risk
among British physicians
P
British physicians
I
Smoking (various doses)
C
No smoking
O
Lung cancer incidence
“The clinical evidence implicating frequent
consumption of sugar in the etiology of caries is
much stronger than the evidence supporting the
widely held belief that caries is an infectious disease
caused by mutans streptococci. This contention is
mainly based on studies in coprophagous rodents,
and attempts to control caries using this approach
have been unsuccessful thus far. However, there
are not any multi-billion dollar industries with a
vested interest in discounting the role of a specific
micro-organism.”
D.T. Zero. Caries Research 2004; 38: 277-285
THE
OBVIOUS
?
Journal of the American Medical Association June 9, 1928
Adolf Hitler
Martin Borman
Reidar
Sognnaes
1911-1948
ADVERTISING
Framing the Health Issue
Sugar in
the child’s
diet is a
support to
his growth
…a
necessary
fuel
Máh-to-tóh-pa, Four
Bears, Second Chief, in
Full Dress, 1832
George Catlin
(1796 –1872)
Sugar is
the most
prominent
fuel
burned in
the body
Fear of
decay….
The
remedy is
to keep
the teeth
clean
Sugar
will…
“hit the
spot….”
1930
Sugar is
not an
essential
part of
the diet
Coca-Cola has the same level of
acidity as many other foods and
drinks. And when you think
about it, drinks like Coca-Cola
are swallowed quite quickly and
the saliva in your mouth washes
away the liquid. Dental hygiene
is the key! Make sure you look
after your teeth by brushing
regularly and visiting your
dentist. In fact, tooth decay is
declining globally, even as soft
drink consumption has
increased. This all means
there’s no real reason why you
can’t enjoy Coca-Cola.
PROFESSIONAL
ORGANIZATIONS
The belief that… pure sugar may
cause tooth decay has received
considerable attention. The
consensus of opinion is that
sugar in itself has no harmful
effect…
Bing – Secretary of AMA – Authorized by
CDT October 1932
In light of current laboratory and
epidemiological research findings, the
Association recognizes that it is neither
advisable nor appropriate to eliminate
from the American diet sugarcontaining foods that
provide necessary energy value for
optimal nutrition.
http://www.ada.org/sections/about/pdfs/doc_policies.pdf
Current Policies
“dental health problems do
not require any dietary
recommendations”
and “frequent consumption
of candy did not seem to
be a significant
determinant of caries”
ACADEMIA
F. J. Stare Science 1968.
Like Hansel and Gretel
Linus Pauling is lost in the
woods – of health and
nutrition, areas outside his
competence”.
ICOS
Lipid Research Clinics Coronary
Prevention Trial ($140 million)
Screen 500,000
Enroll: 3806
Cholesterol distribution
Middle-aged Males
Middle-aged Females
Drug and Death
Death
+
-
68 (3.57%) 1839
1906
Placebo 71 (3.74%) 1828
1900
Drug
NNT=591
JAMA, 1984
Drug and CHD
CHD
+
-
160 (8.4%) 1746
1906
Placebo 188 (9.9%) 1712
1900
Drug
NNT=67
JAMA, 1984
Conclusion: those benefits “could
and should be extended to other
age groups and woman and …
other more modest elevations of
cholesterol levels”
Enrollment of patients in
NSAIDS trials
Age
>65 yrs old
<65 yrs old
Rochon, 1998 CMA 159(11)
Bodenheimer, 2000, NEJM 1539
Rofecoxib
Are the patients in the trial similar
to the patients in our chair?
Rofecoxib and dental pain
Condition
Mean Exclusion criteria
Age
Post-Dental 18
Surgery Pain
Duration
Allergies to any anti-inflammatory,
1 day
asthma, diabetes, renal, cardiovascular
or neoplastic disease, neurological
disorders or clinically significant
abnormalities on prestudy clinical
examination or laboratory tolerability tests
including a complete blood count, serum
chemistries, and urine analysis
P
OS
Cox-2 inhibitor for dental pain
• Two double-blind randomized trials
published in JADA
• 406 subjects
• Comparison of:
– 20 mg Cox-2
– 40 mg Cox-2
– 10 mg oxycodone/1000 mg acetaminophen
• Conclusion: Cox-2 is an efficacious and
safe alternative to Percocet
Surprise?
• Oxycodone — Half Life: 3 - 4.5 Hours
• Valdecoxib — Half Life: 8 to 11 Hours
“Madison Ave. Has Growing Role
In the Business of Drug Research”
• The FDA specifically refused thatthis drug
be prscribed for pain control
• “Contrived control” (NYT)
“…efforts to encourage
doctors to prescribe Bextra …
for uses that the US Food &
Drug Administration had
specifically refused to
authorise.”
Contrived control groups
• Antibiotics and meningitis
– Give controls 1/3 of standard dose (Science, 2001
Sept. 7 Vol 293, p.1742)
Fluconazole vs. Amphotericin B
Fungal skin infection
+
-
Fluconazole
7 (1.7%)
413
420
Amph B
11 (2.7%)
396
400
Ann Intern Med. 1994;120:913-918
JAMA 1999; 282(18):1756
“The majority of patients (79%) were
provided with oral amphotericin B,
which is poorly absorbed and poorly
documented” JAMA 1999
In the United States, only an
intravenous (IV) form of
amphotericin B is available.
http://www.thebody.com/content/art4743.html
PIC
A example of a surrogate
Surrogates are scary
• Medication lowers the rate of ventricular
arrhythmias (TRUE)
• Ventricular arrhythmias increase mortality
risk (TRUE)
• Medication lowers the rate of mortality:
(FALSE)
Additional Examples
Disease
Surrogate
Tangible
Outcome
AIDS event
Misleading
AIDS
CD-4
Osteoporosis Bone density
Fracture
yes
Cancer
Tumor size
Mortality
yes
Periodontitis
Pocket depth
Tooth loss
?
Caries
Enamel caries
Pain/tooth loss
?
yes
Outcome Measures
– a surrogate outcome is a laboratory sign or a physical
sign used as a substitute for a clinically meaningful
endpoint that measures directly how a patient feels,
functions or survives. Changes induced by therapy on
a surrogate endpoint are expected to reflect changes
in a clinically meaningful endpoint (Temple, 1995).
– a true outcome reflects unequivocal evidence of
tangible patient benefit. True endpoints include
Quality of life measures
The acceptance of drugs based
on surrogate endpoints may
potentially reflect a fundamental
flaw in the drug approval process
… possibly, a major drug tragedy
will be required to lead to
revisions in the drug-approval
process in the United States
[Psaty et al. 1999].
Surrogate Endpoints & Validity
Enamel protein loss
Upstream surrogates
Subclinical mineral loss
White spot/sticky fissure
WHO class I cavity
WHO class II cavity
WHO class III cavity
River mouth
Tooth Loss
Downstream surrogates
River source
PICO and implants
PICO
• Surrogates:
– Chewing time: The time between the
beginnings of mastication to the swallowing of
the food bolus.
– Cleaning time:the time between the end of
rhythmic mastication and the final swallow
Awad et al., 2000 J. Dent. Res. 79: 1659
PICO: surrogates
• Chewing time and cleaning time of
different types of foods were not depended
on treatment allocation.
• Correlations between the laboratory
assessment of masticatory efficiency and
subjects’ ratings of ease of chewing the
same foods were low and non-significant.
Awad et al., 2000 J. Dent. Res. 79: 1659
PICO: True Endpoints
Functional limitations
Physical Pain
Psychological comfort
Physical disability
Psychological disability
Social disability
Handicap
Implant
14.4
12.5
7.1
12.1
7.9
5.5
6.7
Conventional
18.5
18.7
10.3
15.8
10.6
7.0
8.3
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