12 June 2004Clinical algorithms in public health1 Seminar on “Intelligent data analysis and data...
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Transcript of 12 June 2004Clinical algorithms in public health1 Seminar on “Intelligent data analysis and data...
12 June 2004 Clinical algorithms in public health 1
Seminar on “Intelligent data analysis and data mining – Application in medicine”
Research on poisonings Research on poisonings in children: public in children: public
health perspective for health perspective for the development of the development of clinical algorithmsclinical algorithms
byDr Sergio Pièche
12 June 2004 Clinical algorithms in public health 2
Developing clinical algorithms in public health
The problem
The target
Principles
Research
12 June 2004 Clinical algorithms in public health 3
Developing clinical algorithms in public health: The The
problemproblem
InjuriesInjuries
• Mortality: causing deaths• Morbidity: burden of the
condition• Age group at risk• Costs: hospital and primary
health care• Likely impact of interventions
12 June 2004 Clinical algorithms in public health 4
Developing clinical algorithms in public health: The targetThe target
Health providers at primary health care level:
– Health background: doctors, medical assistants, nurses, other health workers
– Type of facility: equipment, supply, access to referral facility
12 June 2004 Clinical algorithms in public health 5
Developing clinical algorithms in public health: PrinciplesPrinciples
• Safe and effective guidelines: Sensitive and specific clinical signs
Minimum number of clinical signs
Requiring simple skills to be used
Standard and simple assess-classify-treat system
Possible to teach and learn
Minimum number of essential drugs
Best care possible for severe cases
• Safe and effective guidelines: Sensitive and specific clinical signs
Minimum number of clinical signs
Requiring simple skills to be used
Standard and simple assess-classify-treat system
Possible to teach and learn
Minimum number of essential drugs
Best care possible for severe cases
12 June 2004 Clinical algorithms in public health 6
Clinical algorithm
ASSESSMENT:signs
CLASSIFICATION:for action
TREATMENT:the action
Danger signs SEVEREReferral:
pre-referral treatment
Other signs MODERATETreatment (follow-up
needed)
Other signs or no signs
MILD Home care
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Developing clinical algorithms in public health: ResearchResearch
•Hydrocarbon poisoning
•Organophosphate poisoning
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Developing clinical algorithms in public health: Research Research
on poisoning: prospective on poisoning: prospective studystudy
Clinical predictors of severity of accidental poisoning from hydrocarbons and organophosphates in children below 5 years old
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Developing clinical algorithms in public health: Research on Research on
poisoning: aimpoisoning: aim
…to develop an algorithm for the
outpatient management of
children with hydrocarbon and
organophosphate poisonings at
primary health care facilities in
developing countries.
12 June 2004 Clinical algorithms in public health 10
Developing clinical algorithms in public health: Research Research
stepssteps
• Derivation of clinical decision
rule (factors with predictive power)
• Prospective validation of the algorithm in different settings
• Provider performance analysis
• Impact
12 June 2004 Clinical algorithms in public health 11
Developing clinical algorithms in public health: Research Research
approachapproach• Identification and standard
definition of signs and symptoms
• Gold standards for diagnoses
• Definition of outcomes
• Observer variability and bias
• Procedures (protocol and instruments; training, supervision)
12 June 2004 Clinical algorithms in public health 12
Developing clinical algorithms in public health: Research Research
methodology - 1methodology - 1
EnrolmentEnrolment• Children 2 to 59 months old
• History: unintentional exposure to hydrocarbons or organophosphates
• Acute exposure
• Seen within 48 hours of exposure to poison
• New cases
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Developing clinical algorithms in public health: Research Research
methodology - 2methodology - 2ProceduresProcedures
• All children admitted for at least 48 hours post-exposure irrespective of severity (written consent and free admission)
• Examined by study physician + investigations upon admission
• Followed up at 6, 12, 24, 48 hours post-exposure
• No delay or interference with quality care
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Follow-up
Post-exposure
OPD/ER6 hours
Follow-up
12 hours
Follow-up
24 hours
Follow-up
48 hours
Follow-upDischarge
/ death
Cl. exam.(Lab tests;
X-ray)
Intermediate outcomesFinal
outcome
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E.g. Hydrocarbon poisoning
•Respiratory signs:cough, fast breathing,etc•Vomiting•…
Chemicalpneumonitis
OutcomeBacterial
pneumonia
Severity
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Developing clinical algorithms in public health: Research Research
methodology - 3methodology - 3
Sample sizeSample size• To detect the overall association and prediction
of common symptoms and signs with poisoning severity and outcome
• To account in the analysis for stratification of cases in sub-groups based on time of exposure to poison
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Key questions
• Which common clinical signs and symptoms best predict poisoning severity and outcome?
• How long is the safe clinical observation period before sending home a child who has been exposed to hydrocarbons or organophosphates?
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Developing clinical algorithms in public health: Research: Research:
AnalysisAnalysis
• Chi-square statistics or Fisher exact test, risk differences, risk ratios, odds ratios
• Multivariate logistics regression - incl. stepwise techniques
• Data mining techniques to be considered• Sensitivity, specificity, predictive accuracy
12 June 2004 Clinical algorithms in public health 19
Data analysis:
The challenge!
The challenge!