Bayesian modeling to unmask and predict influenza A/H1N1pdm dynamics in London.

The tracking and projection of emerging epidemics is hindered by the disconnect between apparent epidemic dynamics, discernible from noisy and incomplete surveillance data, and the underlying, imperfectly observed, system. Behavior changes compound this, altering both true dynamics and reporting patterns, particularly for diseases with nonspecific symptoms, such as influenza. We disentangle these effects to unravel the hidden dynamics of the 2009 influenza A/H1N1pdm pandemic in London, where surveillance suggests an unusual dominant peak in the summer. We embed an age-structured model into a bayesian synthesis of multiple evidence sources to reveal substantial changes in contact patterns and health-seeking behavior throughout the epidemic, uncovering two similar infection waves, despite large differences in the reported levels of disease. We show how this approach, which allows for real-time learning about model parameters as the epidemic progresses, is also able to provide a sequence of nested projections that are capable of accurately reflecting the epidemic evolution.

An analysis of the economic and patient outcome impact of an integrated COPD service in east London.

Exacerbations of COPD carry a huge burden of morbidity and a significant economic impact. It has been shown that home care may be useful for exacerbations of COPD. This article presents a review of an integrated COPD service in east London. Hospital Episode Statistics, Public Health Mortality Files and clinical data were used to analyze differences in health care usage and COPD patient outcomes, including COPD assessment test (CAT) scores for a subsample, before and after the introduction of the integrated service. There was a significant (30%) reduction in the number of hospital bed days for COPD patients (P<0.05), alongside a significant increase in patients with only a short stay (0-1 days) in hospital (P<0.0001). There was a significant increase in the number of patients dying outside of hospital (a proxy for quality of end-of-life care) following introduction of the service (P=0.00015). Patients also reported a clinically significant improvement in CAT scores. A locally developed economic model shows that the economic benefits of the service (via impact on place of death and reduction in length of hospital stay) were almost equal to the cost of the service. The increase in proportion of short-stay admissions and the reduction in bed days suggest an impact of the service on early supported discharge and that this along with an improvement in patient clinical outcomes and in quality of end-of-life care shows that an exemplar integrated COPD service can provide benefits that equate to a nearly cost-neutral service.