BackgroundStrategies to control varicella vary across Europe. Evidence from established programmes has prompted the United Kingdom to re-evaluate the need for universal vaccination. The burden of complicated varicella is a key parameter in the cost-effectiveness analysis.
View Article and Find Full Text PDFRandomized, controlled trials are not always possible to evaluate interventions targeting infectious disease. This is frequently the case when evaluating the population-level impact of vaccines or when evaluating interventions aiming to increase vaccine uptake. Under such circumstances, an array of quasi-experimental designs is increasingly being used to evaluate the effects of vaccines on a wide range of morbidity and health service outcomes.
View Article and Find Full Text PDFInterrupted time series analysis differs from most other intervention study designs in that it involves a before-after comparison within a single population, rather than a comparison with a control group. This has the advantage that selection bias and confounding due to between-group differences are limited. However, the basic interrupted time series design cannot exclude confounding due to co-interventions or other events occurring around the time of the intervention.
View Article and Find Full Text PDFBackground: The 2012 Health and Social Care Act (HSCA) in England led to among the largest healthcare reforms in the history of the National Health Service (NHS). It gave control of £67 billion of the NHS budget for secondary care to general practitioner (GP) led Clinical Commissioning Groups (CCGs). An expected outcome was that patient care would shift away from expensive hospital and specialist settings, towards less expensive community-based models.
View Article and Find Full Text PDFInterrupted time series (ITS) analysis is a valuable study design for evaluating the effectiveness of population-level health interventions that have been implemented at a clearly defined point in time. It is increasingly being used to evaluate the effectiveness of interventions ranging from clinical therapy to national public health legislation. Whereas the design shares many properties of regression-based approaches in other epidemiological studies, there are a range of unique features of time series data that require additional methodological considerations.
View Article and Find Full Text PDFPurpose: We examined the association between childhood respiratory infections and adult lung function and how this association varies depending on the age at infection.
Methods: The Barry Caerphilly Growth study collected information on childhood upper and lower respiratory tract infections (URTI, LRTI) from birth to 5 years on 14 occasions. Subjects were traced prospectively and had lung function measured at age 25 years.