Evidence-based Medicine Workbook - Simorgh Research Repository

Prediction (prognosis)
Prediction or prognosis questions are concerned with how likely an outcome is
for a population with certain characteristics (risk factors), such as the likelihood
that a man who is experiencing atypical chest pains will suffer further heart
failure or sudden death within the next few days, or the predicted morbidity
and mortality for a person diagnosed with colon cancer.
Example 1
Childhood seizures are common and frightening for the parents and the
decision to initiate prophylactic treatment after a first fit is a difficult one.
To help parents make their decision, you need to explain the risk of further
occurrences following a single seizure of unknown cause.
P
I
C
Population/patient
Intervention/indicator
Comparator/control
= children
= one seizure of unknown cause
= no seizures
O Outcome = further seizures
Question:
‘In children who have had one seizure of unknown cause, compared with
children who have had no seizures, what is the increased risk of further
seizures’
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