Outline of presentation

1

• Outline of presentation
• Key messages
• HFA
• Thoughtful physicians Difficult Questions
• EBM
• Measurement Iterative Loop
• COPCORD / WHO / ILAR Studies
• In conclusion

2
The cyclic process of differential diagnosis

• Listen
• Listen
• Listen

listen generate hypotheses
cross examine to gather data for hypothesis
testing
test hypotheses
NO
is one of the hypotheses valid?
YES
TAKE ACTION
3

• How do I select the appropriate diagnostic test?
• 1) Diagnostic tests RARELY reveal a patients
  true state with certainty.
• 2) Test selection should be restricted to those
  
• diagnostic tests whose results could
  change
• physicians mind as to what should be
  done
• for a patient.
• 3) Physicians often start treatment despite
• uncertainty about true state of patient.

4
Number of diagnostic hypotheses remaining
during The steps of evaluating a symptom
chief complaint
Number of diagnoses to be considered
history
physical exam
tests
5
Equal chance of occurring or not occurring
Certain not to occur
Certain to occur
0
0.5
1.0
Probability of disease - 1
6
Posterior Probability
Prior Probability
0
0.5
1.0
Probability of disease - 2
7
Pdisease 0.06
0
0.5
1.0
Probability of disease - 3
8

• EBM Essential Steps Flowchart
• 1) Convert information needs into answerable
  questions
• 2) Track down, with maximum efficiency, the best
  evidence with which to answer them (from the
  clinical examination, the diagnostic laboratory,
  the published literature, or other sources)
• 3) Critically appraise that evidence performance
  for its validity (closeness to the truth)
  usefulness (clinical applicability)
• 4) Apply the results of this appraisal in
  clinical practice
• 5) Evaluate performance

9
Clinical knowledge, experience, skills, guts,
flair
Patient Preferences
Best Evidence
Diagnosis, Therapy, Prognosis
Performance
Fig Flowchart of evidence-based medicine
(adapted from Jenicek7)
10

• Clinical aphorisms
• 1) If you hear hoofbeats, think of horses,
• not zebras
• 2) Rare manifestations of common diseases are
• often more likely than common
  manifestations of rare diseases
• 3) If a test is unlikely to change the management
  of the patient, dont do the test
• 4) If a test result surprises you, repeat the
  test
• before taking action
• 5) The first priority in differential diagnosis
  is to
• think about the diseases you cant
  afford to miss

11

• Outline of presentation
• Key messages
• HFA
• Thoughtful physicians Difficult Questions
• EBM
• Measurement Iterative Loop
• COPCORD / WHO / ILAR Studies
• In conclusion

12
Measurement Iterative Loop
Burden of Illness (Assessment)
Monitoring Reassessment
Etiology or Causation
Diagnosis
Prognosis
Synthesis Implementation of Program
Community Effectiveness
Therapy
Policy Process
Efficiency
13
Relevance of population based studies Prevalen
ce Incidence Risk factors Protective
factors Knowledge, Attitude, Practice
Behavior
14

• Relevance of population based studies - 1
• Prevalence No. of affected persons present in
  
• the population at a specific time
• -------------------------
  --------------------
• No. of persons in the
  population
• at that time
• Implication
• - Useful measure of burden of disease
• Age/gender prevalence
• Valuable for planning health services
• allocating resources (M)
• Spectrum of disease seen (mild /moderate
  /severe)

15
Relevance of population based studies -
2 Incidence No. of new cases that occur
during a specific period of time
-----------------------------------------
population at risk of developing the
disease Implication Helpful in exploring
the relationship of an exposure the risk of
disease e.g. sore throat RF Rheumatic fever
licks the joint and bites the heart
16
Relevance of population based studies - 3 Risk
factors Factors associated with occurrence
of disease most likely to be present prior
to the onset of disease Implication Risk
factors potential causal implications eg.
Hypertension heart disease
17
Relevance of population based studies -
4 Protective factors Those which appear to
have an inverse association with the presence or
development of disease Implication For
potential treatment or even prevention
of disorders eg. Low fat diet atherosclerosis
18
Relevance of population based studies -
5 Knowledge, Attitude, Practice, Behavior
(KAPB) Studies Assess the knowledge, attitude,
practice behavior of a particular disease in
the population Implication - Health
behavior - Treatment seeking behavior - Complian
ce of treatment
19

• Outline of presentation
• Key messages
• HFA
• Thoughtful physicians Difficult Questions
• EBM
• Measurement Iterative Loop
• COPCORD / WHO / ILAR Studies
• In conclusion

20

• The Bhigwan (India) COPCORD Study
  Publications
• The Bhigwan (India) COPCORD Methodology First
  Information Report
• A Chopra, J Patil, V Billampelly, J Relwani, HS
  Tandale
• APLAR Journal of Rheumatoloty, September 1997
• - Prevalence of Rheumatic diseases in a Rural
  Population in Western India
  A WHO-ILAR COPCORD Study
• A Chopra, J Patil, V Billampelly, J
  Relwani, HS Tandale
• J Assoc Physicians India, February 2001
• - Pain disability, perceptions beliefs of a
  Rural Indian Population A
  WHO-ILAR COPCORD study
• A Chopra, M Saluja, J Patil, HS Tandale
• The Journal of Rheumatology, 2002

21
The Bhigwan (India) COPCORD Methodology
First Information Report - 1 Study objective
Well stated Study population Characteristics
well defined compared with national level
(generalizability) Study team COPCORD team
good representation of local resources
(manpower) Study design Cross-sectional
community based study Chopra et al.
APLAR Journal of Rheumatology September 1997
22
The Bhigwan (India) COPCORD Methodology
First Information Report - 2 Study instruments
Standardized COPCORD questionnaires -
Questions translated to local language -
Validated on 50 referral patients
(General population)
Chopra et al. APLAR Journal of Rheumatology
September 1997
23

• The Bhigwan (India) COPCORD
• Methodology first information report - 3
• Survey teams Trained Community Health Workers
• COPCORD Medical Team One rheumatologist, one
• orthopedic surgeons, one rural doctor, two
• rheumatology research associates
• Data collection
• House to house daily visits
• Daily operations were supervised
• Due care was taken to look at the NON respondents
• - Results well presented

Chopra et al. APLAR Journal of Rheumatology
September 1997
24

• Prevalence of Rheumatic diseases in a Rural
  Population in Western India
• A WHO-ILAR COPCORD Study - 1
• Prevalence data from 1st rural Indian COPCORD
  survey in Bhigwan
• Cross-sectional survey n 6034
• Significant rural spectrum of rheumatic-musculoske
  letal symptoms/diseases (RMSD)

Chopra et al. JAPI 2001
25
Prevalence of Rheumatic diseases in a Rural
Population in Western India A WHO-ILAR COPCORD
Study - 2
Conditions Prevalence Remarks
Rheumatoid arthritis 0.5 (95 CI 0.3-0.7) Highest ever reported from an Asian Rural COPCORD study
Osteoarthritis 5.8 -
Inflammatory arthritis 0.9 -
Soft tissue rheumatism general 3.2 -
Soft tissue rheumatism - regional 2.3 -
Chopra et al. JAPI 2001
26

• Pain disability, perceptions beliefs of
• a Rural Indian Population
• A WHO-ILAR COPCORD study
• lt 25 of patients perceive that they have severe
  problem which influences their work ability
  personal life
• 21 did not perceive a need to see a doctor
• Implications
• Health seeking behavior
• Treatment Compliance
• Cost quality of life implications

Chopra et al. The Journal of Rheumatology 2002
27

• Outline of presentation
• Key messages
• HFA
• Thoughtful physicians Difficult Questions
• EBM
• Measurement Iterative Loop
• COPCORD / WHO / ILAR Studies
• In conclusion

28
Measurement Iterative Loop
Burden of Illness (Assessment)
Monitoring Reassessment
Etiology or Causation
Diagnosis
Prognosis
Synthesis Implementation of Program
Community Effectiveness
Therapy
Policy Process
Efficiency
29
Relationship between incidence prevalence
Incidence
Prevalence
Recovery
Death
30

• In conclusion ..
• Key messages
• HFA
• Thoughtful physicians Difficult Questions
• EBM
• Measurement Iterative Loop
• COPCORD / WHO / ILAR Studies
• In conclusion

31
Inferior doctors treated the patients disease,
Mediocre doctors treat the patient as a person,
Superior doctors treat the community as a
whole.
- Huang Lee, 2600 BC