Download Public Health Perspective for the Development of Clinical Algorithm

Seminar on “Intelligent data
analysis and data mining –
Application in medicine”
Research on poisonings in
children: public health
perspective for the
development of clinical
algorithms
by
Dr Sergio Pièche
12 June 2004
Clinical algorithms in public health
1
Developing clinical algorithms
in public health
The problem
The target
Principles
Research
12 June 2004
Clinical algorithms in public health
2
Developing clinical algorithms
in public health: The problem
Injuries
• 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
3
Developing clinical algorithms
in public health: The 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
4
Developing clinical algorithms
in public health: Principles
• 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
5
Clinical algorithm
ASSESSMENT: CLASSIFICATION:
signs
for action
Danger signs
SEVERE
Other signs
MODERATE
Other signs or
no signs
MILD
12 June 2004
Clinical algorithms in public health
TREATMENT:
the action
Referral:
pre-referral
treatment
Treatment
(follow-up
needed)
Home care
6
Developing clinical algorithms
in public health: Research
• Hydrocarbon poisoning
• Organophosphate poisoning
12 June 2004
Clinical algorithms in public health
7
Developing clinical algorithms
in public health: Research on
poisoning: prospective study
Clinical predictors of severity of
accidental poisoning from
hydrocarbons and
organophosphates in children
below 5 years old
12 June 2004
Clinical algorithms in public health
8
Developing clinical algorithms
in public health: Research on
poisoning: 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
9
Developing clinical algorithms
in public health: Research steps
• 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
10
Developing clinical algorithms in
public health: Research approach
• 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
11
Developing clinical algorithms
in public health: Research
methodology - 1
Enrolment
• 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
12 June 2004
Clinical algorithms in public health
12
Developing clinical algorithms
in public health: Research
methodology - 2
Procedures
• All children admitted for at least 48 hours postexposure 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
12 June 2004
Clinical algorithms in public health
13
Follow-up
Post-exposure
OPD/ER
6 hours
12 hours 24 hours 48 hours Discharge
/ death
Follow-up Follow-up Follow-up Follow-up
Cl. exam.
(Lab tests;
X-ray)
Intermediate outcomes
12 June 2004
Clinical algorithms in public health
Final
outcome
14
E.g. Hydrocarbon poisoning
•Respiratory Chemical
signs:
pneumonitis
cough, fast
Outcome
breathing,etc
•Vomiting
Bacterial
•…
pneumonia
Severity
12 June 2004
Clinical algorithms in public health
15
Developing clinical algorithms
in public health: Research
methodology - 3
Sample 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
12 June 2004
Clinical algorithms in public health
16
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?
12 June 2004
Clinical algorithms in public health
17
Developing clinical algorithms
in public health: Research:
Analysis
• 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
18
Data analysis:
12 June 2004
Clinical algorithms in public health
19