Events
CRiSM Seminar
Prof Antony Pettitt, Lancaster University
Statistical inference for
assessing infection control measures for the transmission of pathogens in
hospitals
Patients can acquire infections from pathogen
sources within hospitals and certain pathogens appear to be found mainly in
hospitals. Methicillin-resistant Staphylococcus
Aureus (MRSA) is an example of a hospital acquired pathogen that continues
to be of particular concern to patients and hospital management. Patients infected with MRSA can develop
severe infections which lead to increased patient morbidity and costs for the
hospital. Pathogen transmission to a
patient can occur via health-care workers that do not regularly perform hand
hygiene. Infection control measures that
can be considered include isolation for colonised patients and improved hand
hygiene for health-care workers.
The talk develops statistical methods and
models in order to assess the effectiveness of the two control measures (i)
isolation and (ii) improved hand hygiene.
For isolation, data from a prospective study carried out in a London hospital is
considered and statistical models based on detailed patient data are used to
determine the effectiveness of isolation.
The approach is Bayesian. For hand hygiene it is not possible, for
ethical and practical reasons, to carry out a prospective study to investigate
various levels of hand hygiene. Instead
hand hygiene effects are investigated by simulation using parameter values
estimated from data on health-care worker hand hygiene and weekly colonisation
incidence collected from a hospital ward in Brisbane.
The approach uses profile likelihoods.Both approaches involve transmission
parameters where there is little information available and contrasting
compromises have to be made. Conclusions about
the effectiveness of the two infection control measures will be discussed. The talk involves
collaborative work with Marie Forrester, Emma McBryde, Chris Drovandi, Ben
Cooper, Gavin Gibson, Sean McElwain.