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Asking Answerable Asking Answerable Clinical Clinical QQuestionsuestions
Five steps of EBM PracticeFive steps of EBM Practice
1 Translation to an answerable questionTranslation to an answerable question2 Efficient searching of the best evidenceEfficient searching of the best evidence3 Critical appraisal of the evidence for its Critical appraisal of the evidence for its
validity and clinical applicability validity and clinical applicability 4 Integration of that critical appraisal with Integration of that critical appraisal with
clinical expertise and the patient’s unique clinical expertise and the patient’s unique biology and beliefs biology and beliefs
5 Evaluation of one’s performance. Evaluation of one’s performance.
Case ReportCase Report► The patient is a 77-year-old man 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.
► On examination, his respiratory rate is 28, his heart rate is 108 and his temperature is 39.2°C. There is bronchophony and egophony in the left lower posterior lung field.
► Initial blood tests show leukocytosis and hyponatremia.
A medical students’ A medical students’ questions:questions:
1.1. What microbial organisms can cause What microbial organisms can cause community-acquired pneumonia?community-acquired pneumonia?
2.2. How does pneumonia cause How does pneumonia cause egophony?egophony?
3.3. What is the incidence of community-What is the incidence of community-acquired pneumonia?acquired pneumonia?
Background KnowledgeBackground Knowledge
►The students’ questions ask for The students’ questions ask for general or general or “background”“background” knowledge knowledge about pneumonia, the disorder that about pneumonia, the disorder that presumably explains much of this presumably explains much of this patient’s acute illness. patient’s acute illness.
Background questionsBackground questions
► Ask for general knowledge about a Ask for general knowledge about a disorderdisorder
► Have two essential components:Have two essential components:1.1. A question root (who, what, where, A question root (who, what, where,
when, how, why) with a verbwhen, how, why) with a verb
2.2. A disorder, or an aspect of a disorderA disorder, or an aspect of a disorder
A practitioners’ questions:A practitioners’ questions:► In this patient are any clinical findings In this patient are any clinical findings
sufficiently powerful to confirm or exclude sufficiently powerful to confirm or exclude pneumonia?pneumonia?
► In this patient is a chest radiograph In this patient is a chest radiograph necessary for the diagnosis?necessary for the diagnosis?
► In this patient is the probability of In this patient is the probability of Legionella Legionella infection sufficiently high to warrant infection sufficiently high to warrant considering covering this organism with the considering covering this organism with the initial antibiotic choice?initial antibiotic choice?
► In this patient , do clinical features predict In this patient , do clinical features predict outcome well enough that as a “low risk” outcome well enough that as a “low risk” patient can be treated safely at home?patient can be treated safely at home?
Foreground KnowledgeForeground Knowledge
►The practitioners’ questions ask for The practitioners’ questions ask for specific knowledge about how to specific knowledge about how to diagnose, “prognose”, and treat the diagnose, “prognose”, and treat the patients with pneumonia, which might patients with pneumonia, which might be called be called “foreground”“foreground” knowledge. knowledge.
►Ask for specific knowledge about Ask for specific knowledge about managing patients with a disordermanaging patients with a disorder
Foreground” questions
► Have four (or three) essential Have four (or three) essential components:components:
1.1. The patient and/or problem of interestThe patient and/or problem of interest
2.2. The main intervention (defined very The main intervention (defined very broadly, including an exposure, a broadly, including an exposure, a diagnostic test, a prognostic factor, a diagnostic test, a prognostic factor, a treatment, a patient perception, and so treatment, a patient perception, and so forth)forth)
3.3. Comparison intervention(s), if relevantComparison intervention(s), if relevant
4.4. The clinical outcome(s) of interest.The clinical outcome(s) of interest.
Background and foreground questionsBackground and foreground questions
Background
Foreground
Experience with Condition
Background VS. Foreground Background VS. Foreground KnowledgeKnowledge
►Clinical practice demands that we use Clinical practice demands that we use large amounts of both “background” large amounts of both “background” and “foreground” knowledge. and “foreground” knowledge.
The components:1The components:1
► Think about who / what you wish to apply this Think about who / what you wish to apply this evidence to… e.g.evidence to… e.g. People with a particular disorder?People with a particular disorder?
► e.g chronic recurrent cystitise.g chronic recurrent cystitis
People in a particular care setting?People in a particular care setting?► e.g. communitye.g. community
particular groups of peopleparticular groups of people► e.g. sexually active young women?e.g. sexually active young women?► the elderly?the elderly?► children?children?
► How would you describe your clients / setting?How would you describe your clients / setting?
The components:2The components:2
►The intervention / topic of interest The intervention / topic of interest (e.g. cause, change in practice etc.) (e.g. cause, change in practice etc.) e.g.e.g. Use of cranberry juice (as a drink)Use of cranberry juice (as a drink) Might want to specify how much / how Might want to specify how much / how
oftenoften For complex interventions may need to For complex interventions may need to
give specific detail / consideration to the give specific detail / consideration to the description…description…
►What exactly am I considering…?What exactly am I considering…?
The components:3The components:3
►The comparison or alternative (not The comparison or alternative (not applicable to all questions) e.g.applicable to all questions) e.g. Anti-biotic therapy?Anti-biotic therapy? Nothing?Nothing? Fluids alone?Fluids alone?
►What alternatives actions might I try?What alternatives actions might I try?
The components:4The components:4
► The outcome… e.g.The outcome… e.g. CureCure Duration of diseaseDuration of disease preventionprevention DeathDeath Side effectsSide effects Pain (reduced)Pain (reduced) WellbeingWellbeing
► What am I hoping to accomplish (what What am I hoping to accomplish (what outcomes might reasonably be affected…)?outcomes might reasonably be affected…)?
The 4 part clinical questionThe 4 part clinical question
1.1. ““PPopulation”opulation”
2.2. ““IIntervention”ntervention”
3.3. ““CComparison”omparison”
4.4. ““OOutcome”utcome”► ““In adult females does cranberry In adult females does cranberry
juice reduce the duration of urinary juice reduce the duration of urinary tract infection when compared to no tract infection when compared to no treatment”treatment”
4 Domains of EBM4 Domains of EBM
►TreatmentTreatment►DiagnosisDiagnosis►PrognosisPrognosis►Causation/EtiologyCausation/Etiology
TreatmentTreatment
►PP – In a child with frequent febrile – In a child with frequent febrile seizuresseizures
►II – would anticonvulsant therapy – would anticonvulsant therapy►CC – compared to no treatment – compared to no treatment►OO – result in seizure reduction? – result in seizure reduction?
TreatmentTreatment
►P - Among young children with otitis P - Among young children with otitis media, media,
► I - does treatment with AmoxicillinI - does treatment with Amoxicillin►C – compared with placeboC – compared with placebo►O - result in more rapid O - result in more rapid
improvement?improvement?
DiagnosisDiagnosis
►PP – In an otherwise healthy 7-year-old – In an otherwise healthy 7-year-old boy with sore throat,boy with sore throat,
►I - I - how does the clinical examhow does the clinical exam►C C – compare to throat culture– compare to throat culture►OO – in diagnosing Streptococcal – in diagnosing Streptococcal
infection?infection?
DiagnosisDiagnosis
►P P – In a 15 month old child with FTT– In a 15 month old child with FTT►I I – is IgA antigliadin antibodies – is IgA antigliadin antibodies ►CC – comparable to biopsy – comparable to biopsy►OO – in diagnosing celiac disease? – in diagnosing celiac disease?
DiagnosisDiagnosis
►P - Among young children with otitis P - Among young children with otitis media, media,
►I - I - how does the clinical examhow does the clinical exam►C C – compare to tympanocentesis– compare to tympanocentesis►OO – in diagnosing otitis media? – in diagnosing otitis media?
PrognosisPrognosis
►P - In children with Down syndrome,P - In children with Down syndrome,► I - is IQ an important prognostic factor I - is IQ an important prognostic factor ►C – C – ►O – in predicting Alzheimer’s later in O – in predicting Alzheimer’s later in
life?life?
PrognosisPrognosis
►P - Among young children with otitis P - Among young children with otitis media, media,
► I - is parents smoking an important I - is parents smoking an important prognostic factor prognostic factor
►C – C – ►O – in predicting frequency of disease? O – in predicting frequency of disease?
Etiology/HarmEtiology/Harm
►P – In otherwise healthy childrenP – In otherwise healthy children► I - exposed in utero to cocaine,I - exposed in utero to cocaine,►C – compared to children not exposedC – compared to children not exposed►O – have increased incidence of O – have increased incidence of
learning disabilities at age six years?learning disabilities at age six years?
Etiology/HarmEtiology/Harm
►PP – Does a newborn – Does a newborn ►II – given vitamin K at birth – given vitamin K at birth►C C – compared to no vitamin K– compared to no vitamin K►OO – have an increase in cancer later in – have an increase in cancer later in
life?life?
Etiology/HarmEtiology/Harm
►P – Controlling for confounding factors, P – Controlling for confounding factors, do otherwise healthy childrendo otherwise healthy children
► I – who attend daycare,I – who attend daycare,►C – compared to children who do notC – compared to children who do not►O – have increased incidence of otitis O – have increased incidence of otitis
media in the first two years of life?media in the first two years of life?
Factors to consider when deciding Factors to consider when deciding which question to answer first which question to answer first
include:include:1.1. Which question is most important to the Which question is most important to the
patient’s well-being?patient’s well-being?2.2. Which question is most relevant to our Which question is most relevant to our
learners’ needs?learners’ needs?3.3. Which question is most feasible to answer Which question is most feasible to answer
within the time we have available?within the time we have available?4.4. Which question is most interesting?Which question is most interesting?5.5. Which question is most likely to recur in Which question is most likely to recur in
our practice?our practice?
Educational Prescription
Summary and Further Summary and Further ReadingsReadings
►Chapter 1Chapter 1
