parameters estimated for Salmonella typhimurium in swine using susceptible-infectious-resistant m... more parameters estimated for Salmonella typhimurium in swine using susceptible-infectious-resistant models and unobserved sources of uncertainty (cohort effects, diagnostic test sensitivity), so leading to more reliable estimates Correia-Gomes et al. BMC Veterinary Research 2014, 10:101
ABSTRACTBackground Campylobacteriosis is a major public health concern. Despite evidence that cli... more ABSTRACTBackground Campylobacteriosis is a major public health concern. Despite evidence that climate factors influence the spatio-temporal patterns of the infections; their impact is not fully described and understood. ObjectivesTo examine methods for determining the impact of rainfall and temperature on Campylobacter cases in England and Wales. MethodsReported cases for England and Wales were linked to local temperature and rainfall at laboratory postcode locations in the 30 days before the specimen date. Descriptive, statistical and spatial methods included a novel Comparative Conditional Incidence (CCI), wavelet analysis, hierarchical clustering, generalized additive model (GAM) and generalized structural time series model (GEST).ResultsThe Campylobacter increase in late spring was linked to temperature two weeks prior, with an increase in CCI of 0.175 cases per 100,000 per week for weeks 17 to 24; the relationship was non-linear and changed through the year. GEST with penalized...
Bayes' rule is introduced as a coherent averaging strategy for multiclassifier system (MCS) o... more Bayes' rule is introduced as a coherent averaging strategy for multiclassifier system (MCS) output, and as a strategy for eliminating the uncertainty associated with a particular choice of classifier-model parameters. We use a Markov-Chain Monte Carlo method for efficient selection of classifiers to approximate the computationally intractable elements of the Bayesian approach --- the set of classifiers so selected is our MCS. Furthermore we exploit the massive sampling (thousands of classifiers) within the Bayesian framework to encompass an estimate of the confidence to be placed in any classification result --- thus providing a sound basis for rejection of some MCS classification results. We present uncertainty envelopes as one way to derive these confidence estimates from the population of classifiers that constitutes the MCS, and we show that as the diversity among component classifiers increases so does the accuracy of confident classification estimates, but diversity is not...
The long-term evolution of ozone is influenced by a wide variety of factors that may be broadly s... more The long-term evolution of ozone is influenced by a wide variety of factors that may be broadly separated into radiative, dynamical, transport, chemical and external forcing processes. Many of the processes are also coupled in the sense that, for example, dynamical changes lead ...
One difficulty for real-time tracking of epidemics is related to reporting delay. The reporting d... more One difficulty for real-time tracking of epidemics is related to reporting delay. The reporting delay may be due to laboratory confirmation, logistic problems, infrastructure difficulties and so on. The ability to correct the available information as quickly as possible is crucial, in terms of decision making such as issuing warnings to the public and local authorities. A Bayesian hierarchical modelling approach is proposed as a flexible way of correcting the reporting delays and to quantify the associated uncertainty. Implementation of the model is fast, due to the use of the integrated nested Laplace approximation (INLA). The approach is illustrated on dengue fever incidence data in Rio de Janeiro, and Severe Acute Respiratory Illness (SARI) data in Paran\'a state, Brazil.
Health & social care in the community, Jan 16, 2016
There is a general understanding that socioeconomically disadvantaged people are also disadvantag... more There is a general understanding that socioeconomically disadvantaged people are also disadvantaged with respect to their access to NHS care. Insofar as considerable NHS funding has been targeted at deprived areas, it is important to better understand whether and why socioeconomic variations in access and utilisation exist. Exploring this question with reference to cardiovascular care, our aims were to synthesise and evaluate evidence relating to access to and/or use of English NHS services around (i) different points on the care pathway (i.e. presentation, primary management and specialist management) and (ii) different dimensions of inequality (socioeconomic, age- and gender-related, ethnic or geographical). Restricting our search period from 2004 to 2016, we were concerned to examine whether, compared to earlier research, there has been a change in the focus of research examining inequalities in cardiac care and whether the pro-rich bias reported in the late 1990s and early 2000s...
Recently, a prototype dengue early warning system was developed to produce probabilistic forecast... more Recently, a prototype dengue early warning system was developed to produce probabilistic forecasts of dengue risk three months ahead of the 2014 World Cup in Brazil. Here, we evaluate the categorical dengue forecasts across all microregions in Brazil, using dengue cases reported in June 2014 to validate the model. We also compare the forecast model framework to a null model, based on seasonal averages of previously observed dengue incidence. When considering the ability of the two models to predict high dengue risk across Brazil, the forecast model produced more hits and fewer missed events than the null model, with a hit rate of 57% for the forecast model compared to 33% for the null model. This early warning model framework may be useful to public health services, not only ahead of mass gatherings, but also before the peak dengue season each year, to control potentially explosive dengue epidemics.
parameters estimated for Salmonella typhimurium in swine using susceptible-infectious-resistant m... more parameters estimated for Salmonella typhimurium in swine using susceptible-infectious-resistant models and unobserved sources of uncertainty (cohort effects, diagnostic test sensitivity), so leading to more reliable estimates Correia-Gomes et al. BMC Veterinary Research 2014, 10:101
ABSTRACTBackground Campylobacteriosis is a major public health concern. Despite evidence that cli... more ABSTRACTBackground Campylobacteriosis is a major public health concern. Despite evidence that climate factors influence the spatio-temporal patterns of the infections; their impact is not fully described and understood. ObjectivesTo examine methods for determining the impact of rainfall and temperature on Campylobacter cases in England and Wales. MethodsReported cases for England and Wales were linked to local temperature and rainfall at laboratory postcode locations in the 30 days before the specimen date. Descriptive, statistical and spatial methods included a novel Comparative Conditional Incidence (CCI), wavelet analysis, hierarchical clustering, generalized additive model (GAM) and generalized structural time series model (GEST).ResultsThe Campylobacter increase in late spring was linked to temperature two weeks prior, with an increase in CCI of 0.175 cases per 100,000 per week for weeks 17 to 24; the relationship was non-linear and changed through the year. GEST with penalized...
Bayes' rule is introduced as a coherent averaging strategy for multiclassifier system (MCS) o... more Bayes' rule is introduced as a coherent averaging strategy for multiclassifier system (MCS) output, and as a strategy for eliminating the uncertainty associated with a particular choice of classifier-model parameters. We use a Markov-Chain Monte Carlo method for efficient selection of classifiers to approximate the computationally intractable elements of the Bayesian approach --- the set of classifiers so selected is our MCS. Furthermore we exploit the massive sampling (thousands of classifiers) within the Bayesian framework to encompass an estimate of the confidence to be placed in any classification result --- thus providing a sound basis for rejection of some MCS classification results. We present uncertainty envelopes as one way to derive these confidence estimates from the population of classifiers that constitutes the MCS, and we show that as the diversity among component classifiers increases so does the accuracy of confident classification estimates, but diversity is not...
The long-term evolution of ozone is influenced by a wide variety of factors that may be broadly s... more The long-term evolution of ozone is influenced by a wide variety of factors that may be broadly separated into radiative, dynamical, transport, chemical and external forcing processes. Many of the processes are also coupled in the sense that, for example, dynamical changes lead ...
One difficulty for real-time tracking of epidemics is related to reporting delay. The reporting d... more One difficulty for real-time tracking of epidemics is related to reporting delay. The reporting delay may be due to laboratory confirmation, logistic problems, infrastructure difficulties and so on. The ability to correct the available information as quickly as possible is crucial, in terms of decision making such as issuing warnings to the public and local authorities. A Bayesian hierarchical modelling approach is proposed as a flexible way of correcting the reporting delays and to quantify the associated uncertainty. Implementation of the model is fast, due to the use of the integrated nested Laplace approximation (INLA). The approach is illustrated on dengue fever incidence data in Rio de Janeiro, and Severe Acute Respiratory Illness (SARI) data in Paran\'a state, Brazil.
Health & social care in the community, Jan 16, 2016
There is a general understanding that socioeconomically disadvantaged people are also disadvantag... more There is a general understanding that socioeconomically disadvantaged people are also disadvantaged with respect to their access to NHS care. Insofar as considerable NHS funding has been targeted at deprived areas, it is important to better understand whether and why socioeconomic variations in access and utilisation exist. Exploring this question with reference to cardiovascular care, our aims were to synthesise and evaluate evidence relating to access to and/or use of English NHS services around (i) different points on the care pathway (i.e. presentation, primary management and specialist management) and (ii) different dimensions of inequality (socioeconomic, age- and gender-related, ethnic or geographical). Restricting our search period from 2004 to 2016, we were concerned to examine whether, compared to earlier research, there has been a change in the focus of research examining inequalities in cardiac care and whether the pro-rich bias reported in the late 1990s and early 2000s...
Recently, a prototype dengue early warning system was developed to produce probabilistic forecast... more Recently, a prototype dengue early warning system was developed to produce probabilistic forecasts of dengue risk three months ahead of the 2014 World Cup in Brazil. Here, we evaluate the categorical dengue forecasts across all microregions in Brazil, using dengue cases reported in June 2014 to validate the model. We also compare the forecast model framework to a null model, based on seasonal averages of previously observed dengue incidence. When considering the ability of the two models to predict high dengue risk across Brazil, the forecast model produced more hits and fewer missed events than the null model, with a hit rate of 57% for the forecast model compared to 33% for the null model. This early warning model framework may be useful to public health services, not only ahead of mass gatherings, but also before the peak dengue season each year, to control potentially explosive dengue epidemics.
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