The West Glamorgan asthma study: A statistical analysis.

This thesis is based largely on the analysis of a large data set collected by Iechyd Morgannwg, West Glamorgan County Council and Neath Borough Council, with the aim of discovering whether air borne pollution caused any significant health effects on the lung function of school children aged between 8 and 11 years. Individual time series of daily Peak Expiratory Flow Rate measurements of school children at four different sites in West Glamorgan are related to changes in air borne pollutants such as Nitrogen Oxides, Sulphur Dioxide, Carbon Monoxide, Ozone and PM 10 (particulate dust). Little work has previously been conducted on the acute health effects of air pollution, particularly with respect to children. Recent studies have attempted to model such data, each offering various methodology. This research, however, looks at the longitudinal nature of the data and offers an insight into ways to model it. All modelling was done using the statistical programming language APL. Unlike most other studies the data, upon which this research was based, was plentiful. Many pollutant levels were measured as well as the weather conditions. The children's peak expiratory flow rate readings were accompanied by a questionnaire about the child's previous health symptoms and their home environment. Daily symptom diaries for each day of the study were also kept. This allowed a full and comprehensive analysis to be undertaken, where all confounding factors could be considered. Longitudinal Statistical methods, including the use of Restricted Maximum Likelihood (REML), are applied to investigate the effects of the different pollutant variables