A VERY SIMPLIFIED VERSION OF STATISTICAL METHODS FOR PHARMACOVIGILANCE Prepared for M.Pharm Pharmacology- Clinical Research and Pharmacovigilance

1. Statistical Methods for
Pharmacovigilance
Sanju Kaladharan
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2. Signal
• Reported information on a possible causal
relationship between an adverse event and a
drug, the relationship being unknown or
incompletely documented previously. Usually
more than a single report is required to
generate a signal, depending on the
seriousness of the event and the quality of the
information.
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3. Disproportionality
• Though not a definition, it is the case that
disproportionality is an issue: reporting of
events that are statistically disproportionate
(i.e.an O/E ratio exceeding a specified
threshold), is a signal of disproportionate
reporting.
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11. • Confidence Interval
• A confidence interval is an interval that will
contain a population parameter a specified
proportion of the time. The confidence
interval can take any number of probabilities,
with the most common being 95% or 99%.
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12. Information Component
• where Pr(R|D) is the
posterior probability of
observing a
• specific adverse event R
given that a specific drug D
is the suspect drug.
• Pr(R) and Pr(D) are prior
probabilities of observing R
and D in the entire
database.
• Pr(R,D) is joint probability
that both R and D were
observed in the same
database coincidentally
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17. Multi-item-association analysis
methods
• Multi-item gamma poisson shrinker (MGPS)
• Bayesian confidence propagation neural
network (BCPNN)
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19. BAYESIAN CONFIDENCE PROPAGATION
NEURAl NETWORK (BCPNN)
• The Uppsala Monitoring Centre (UMC) for WHO databases
uses BCPNN architecture for SD
• Neural networks are highly organized & efficient
• Give simple probabilistic interpretation of network weights
• Analogous to a living neuron with its multiple dendrites
and single axon
• BCPNN calculates cell counts for all potential R-D
combinations in the database, not just those appearing in
at least one report
• Done with two fully interconnected layers
• One for all drugs and one for all adverse events
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20. THANK YOU
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