Transcript PICO - Kashan University of Medical Sciences

Asking Answerable
Clinical Question
a five-step process for using an evidence-based
approach in general practice
(1)
(2)
(3)
(4)
(5)
define the problem
track down the information sources you need
critically appraise the information
apply the information with your patients
evaluate how effective this application of
information is.
Clinical scenario
• The patient is a 77-year-old man admitted for
dyspnea and fever. He fell ill 4 days ago with
low-grade fever, chills, myalgias, rhinorrhoea
and a non-productive cough. One day ago he
developed dyspnea on exertion, purulent
sputum, lateral chest wall pain with inspiration
and a shaking chill. His general health is fairly
good; he has had essential hypertension for 12
years, well controlled on diuretic therapy. He has
not smoked.
• On examination, his respiratory rate is 28, his
heart rate is 108 and his temperature is
39.2°C. He may have subtle cyanosis. His
chest expands symmetrically, he has no
prolongation of expiration and no wheezing.
There is bronchophony and egophony in the
left lower posterior lung field.
• Initial blood tests show leukocytosis and
hyponatremia.
• The team suspects acute communityacquired pneumonia with hypoxemia,
and plans chest radiographs, sputum studies,
supplemental oxygen and antimicrobial
therapy.
• what questions you have about this
case?
A medical students’ questions:
1. What microbial organisms can cause
community-acquired pneumonia?
2. How does pneumonia cause egophony?
3. What is the incidence of communityacquired pneumonia?
a.s
• Notice that the students’ questions ask for
general or “background” knowledge about
pneumonia, the disorder that presumably
explains much of this patient’s acute illness.
Type of question
Background
Ask for general knowledge about a disorder
two essential components:
• A question root (who, what, where, when,
how)
• A disorder, or an aspect of a disorder
A practitioners’ questions:
• In this patient are any clinical findings sufficiently
powerful to confirm or exclude pneumonia?
• In this patient is a chest radiograph necessary for
the diagnosis?
• In this patient is the probability of Legionella
infection sufficiently high to warrant considering
covering this organism with the initial antibiotic
choice?
• In this patient , do clinical features predict
outcome well enough that as a “low risk” patient
can be treated safely at home?
• these questions ask for specific knowledge
about diagnosis, prognosis, and treat the
patients with pneumonia, which might be
called “foreground” knowledge.
Type of question
Foreground
1.The patient and/or problem
2.The main intervention (defined very broadly,
including an exposure, a diagnostic test, a prognostic
factor, a treatment, a patient perception, and so forth)
3.Comparison intervention(s)
4.The clinical outcome(s) .
Foreground
Questions
Background
Questions
Experience with Condition
Common Types of question and
study design
– Causation / Etiology
– Diagnosis
– Therapy
– Prognosis
A Good Question should be:
• Relevant - Will the answer matter?
• Answerable - Can the question be
answered by research data?
• Clear - unambiguous
• Worthy - Is the answer worth the work?
Question components : PICO
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What types of
What types of
What types of
What types of
Participants?
Interventions?
Comparison?
Outcomes?
QUESTION:
DESIGN:
Selection?
VALIDITY
Representative?
Participants
Allocation?
I
G
Intervention Group (IG) &
Comparison Group (CG)
CG
Maintenance of allocation?
Outcome
+
-
Concealed allocation?
(Randomised)
comparable groups?
treated equally?
compliant?
+
-
Ascertainment?
A
B
C
D
Measurements
blind subjective? OR
objective?
Measurement of outcomes?
What types of participants?
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
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Disease or condition of interest
Potential co-morbidity
Setting
Demographic factors
What types of intervention?
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
Type of treatment
Type of diagnostic test
Type of causative agent
Type of prognostic factor
What types of outcomes?
• For treatment include all outcomes
important to people making decisions
to define success of therapy
• For prognosis, outcome is the chosen
endpoint of the disease
Patient oriented outcomes
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•
•
•
•
•
Mortality/survival
Disease free period
Quality of life
Work absenteeism
Disability/ Duration and severity of illness
Pain
Example 1
A TV programme has highlighted a hospital
in Suffolk in which a stroke unit has been
set up that specialises in the treatment of
patients who have suffered strokes. The
hospital trust wants to know about the
effectiveness of stroke units in terms of
lives saved before deciding whether to
invest in one.
Patient
Or Problem
Intervention
Comparison
Outcomes
Patient
Or Problem
Patients
who have
suffered
strokes
Intervention
Comparison
Outcomes
Patient
Or Problem
Intervention
Patients
who have
suffered
strokes
Stroke
units
Comparison
Outcomes
Patient
Or Problem
Intervention
Patients Stroke units
who have
suffered
strokes
Comparison
Normal
hospital
care
Outcomes
Patient
Or Problem
Intervention
Comparison
Outcomes
Patients
who have
suffered
strokes
Stroke
units
Normal
hospital
care
Lives
saved
Or
Do stroke units save lives ?
Example
• A acute cough is a common reason for
patients to consult their GP. The causes
of acute cough varies a lot. the treatment
often includes antibiotics.
• The effectiveness of Abx is questionable
and there has been a great deal of
concern about bacterial resistance from
over-prescribing.
Patient
Or Problem
Intervention
Comparison
Outcomes
Patient
Or Problem
Acute
Cough in
primary
care
setting
Intervention
Comparison
Outcomes
Patient
Or Problem
Intervention
Acute
Cough in
primary
care
setting
Antibiotics
Comparison
Outcomes
Patient
Or Problem
Intervention
Comparison
Acute
Cough in
primary
care
setting
Antibiotics
No
antibiotics
Outcomes
Patient
Or Problem
Intervention
Comparison
Outcomes
Acute
Cough in
primary
care
setting
Antibiotics
No
antibiotics
Duration
and
severity of
illness
Patient: Acute Cough in primary care setting
Intervention: Antibiotics
Comparison: No antibiotics
Outcomes: Duration and severity of illness