The overall aim of this research is to provide qualitative data which may help explain the health disadvantage found in quantitative studies among many generations of Irish people in Britain. It examines the ways in which social factors linked to recognised health risks relate to Catholic versus Protestant identity and Irish versus Scottish origin. Using data from 72 qualitative interviews, with people in different religious/ethnic, gender, class and age groups, the analysis focuses on three key areas of social life: employment, communal life and family life. The impact of structural and cultural factors on health and identity, and the ways in which structure and culture are mutually and dynamically constitutive are examined. The evidence points to the health relevance of structural factors (direct and indirect discrimination, and hidden and institutional sectarianism), which are dependent upon externally identifying a cultural difference, Catholic upbringing. These effects on health are theorised to be both via class position and psychosocial pathways, and directly connected to how Catholic identity is maintained and constructed. Over time, since both discrimination and Catholic religious practice are assessed as waning, it may be postulated that past discrimination, while undoubtedly a factor in relation to current ill health, may lose its explanatory force for future ill health. On the other hand, the positive health benefits to be gained by Catholics through being religious are also likely to wane, as a defined religious culture among Catholics becomes less prevalent. The continued perception of the diffuse experience of anti-Catholic bigotry in social life appears to influence health negatively. It seems that it is in the experience of uncertainty and exclusion, that health may be compromised, a particular issue for men’s health, and particularly for middle class ‘younger’ Catholic men who challenge exclusions and boundaries. Thus class is important, as is the ‘classing’ or religious identity. Also, while women may escape past identities, for men this option is not possible. Irish Catholic identity, even as the Irish component is often not explicitly referred to, but rather submerged, may link to health positively and negatively in a number of ways, and links also to an every-changing culture which affects and is affected by wider structures, ideologies and past history. Irish Catholic identity is highly contextualised and differently experienced by gender, class and cohort.

The specific objectives of the study were to: 1. Investigate women's perceptions and experiences of postnatal care; 2. Examine the current pattern of postnatal care provision in terms of clinical outcomes (maternal and neonatal) and maternal satisfaction; 3. Evaluate the new model in terms of clinical outcomes (maternal and neonatal) and maternal satisfaction; 4. Compare the outcomes of both models; and 5. Evaluate midwives' perceptions of both models of care. There were no difference between the two Phases in terms of clinical outcomes (maternal and neonatal) midwifery and maternal satisfaction. In both stages of the study, the average day of postnatal discharge was day three, the mean number of postnatal visits was 4.2, and the average number of midwives to visit a woman was two. Women were very satisfied with the community postnatal care provided by midwives, although concerns were expressed about hospital postnatal care. All women agreed that community postnatal care was an important service and would choose to have the midwife visit her in their own home rather than attend health or drop in centres. Midwives applied aspects of the new template of postnatal visiting and were more likely to visit low risk women three times following introduction of the ne template. There was not change in community of carer. Findings of focus group discussions highlighted that women were not prepared for motherhood and the postnatal period. Women stated that the educational support antenatally and in the postnatal ward did not meet their expectations and needs.

In order to examine the possible health implications of outdoor play areas, this PhD used a multi-methods approach to examine socio-economic variations in the provision, quality and perceptions of publicly available outdoor play areas in Glasgow, with the underpinning philosophy that play areas may be used as a locale for children to engage in physically active play. The locations of play areas were mapped using GIS software and spatial variations were examined by deprivation. A sample (n=100) of play areas in the highest, middle and lowest quintiles of deprivation were visited and an objective quality audit was undertaken assessing their safety and aesthetics. Pupils in P6 (mean age=9.9 years) were recruited from a school in a highly deprived area and a school in an area of low social deprivation. Sixty two “Draw-and-write” activities and four focus groups were conducted with children to investigate preferences for play and benefits and barriers for visiting play areas. Interviews were also conducted with seven play area maintenance men and two mothers to investigate their views on local play provision. Whilst there was greater provision of play areas in deprived areas of Glasgow, some aspects of their quality were poorer. Children and adults spoke about safety from injury and strangers, and a lack of suitable facilities as barriers to using play areas. Vandalism, misuse and youth disorder were also strong themes in all qualitative research. The barriers for play for children from a deprived area were of a more serious nature compared to children from a less deprived area and those aspects of safety and incivilities which were objectively measured as worse in deprived areas, were also ones that acted as barriers for parents and children. Thus, it is those children who may be in greatest need for free access to safe and healthy play spaces that face more (and often more serious) barriers to play. Although play areas might provide children with opportunity to be physically active, access to facilities alone may not always mean they are used. Further research evaluating refurbishments to play areas may help to determine whether improvements made to play areas would impact upon their use and physical activity levels of users.

Abstract When analysing medical or public health datasets, it may often be of interest to measure the time until a particular pre-defined event occurs, such as death from some disease. As it is known that the health status of individuals living within the same area tends to be more similar than for individuals from different areas, event times of individuals from the same area may be correlated. As a result, multilevel models must be used to account for the clustering of individuals within the same geographical location. When the outcome is time until some event, multilevel event history models must be used. Although software does exist for fitting multilevel event history models, such as MLwiN, computational requirements mean that the use of these models is limited for large datasets. For example, to fit the proportional hazards model (PHM), the most commonly used event history model for modelling the effect of risk factors on event times, in MLwiN a Poisson model is fitted to a person-period dataset. The person-period dataset is created by rearranging the original dataset so that each individual has a line of data corresponding to every risk set they survive until either censoring or the event of interest occurs. When time is treated as a continuous variable so that each risk set corresponds to a distinct event time, as is the case for the PHM, the size of the person-period dataset can be very large. This presents a problem for those working in public health as datasets used for measuring and monitoring public health are typically large. Furthermore, individuals may be followed-up for a long period of time and this can also contribute to a large person-period dataset. A further complication is that interest may be in modelling a rare event, resulting in a high proportion of censored observations. This can also be problematic when estimating multilevel event history models. Since multilevel event history models are important in public health, the aim of this thesis is to develop these models so they can be fitted to large datasets considering, in particular, datasets with long periods of follow-up and rare events. Two datasets are used throughout the thesis to investigate three possible alternatives to fitting the multilevel proportional hazards model in MLwiN in order to overcome the problems discussed. The first is a moderately-sized Scottish dataset, which will be the main focus of the thesis, and is used as a ‘training dataset’ to explore the limitations of existing software packages for fitting multilevel event history models and also for investigating alternative methods. The second dataset, from Sweden, is used to test the effectiveness of each alternative method when fitted to a much larger dataset. The adequacy of the alternative methods are assessed on the following criteria: how effective they are at reducing the size of the person-period dataset, how similar parameter estimates obtained from using methods are compared to the PHM and how easy they are to implement. The first alternative method involves defining discrete-time risk sets and then estimating discrete-time hazard models via multilevel logistic regression models fitted to a person-period dataset. The second alternative method involves aggregating the data of individuals within the same higher-level units who have the same values for the covariates in a particular model. Aggregating the data like this means that one line of data is used to represent all such individuals since these individuals are at risk of experiencing the event of interest at the same time. This method is termed ‘grouping according to covariates’. Both continuous-time and discrete-time event history models can be fitted to the aggregated person-period dataset. The ‘grouping according to covariates’ method and the first method, which involves defining discrete-time risk sets, are both implemented in MLwiN and pseudo-likelihood methods of estimation are used. The third and final method to be considered, however, involves fitting Bayesian event history (frailty) models and using Markov chain Monte Carlo (MCMC) methods of estimation. These models are fitted in WinBUGS, a software package specially designed to make practical MCMC methods available to applied statisticians. In WinBUGS, an additive frailty model is adopted and a Weibull distribution is assumed for the survivor function. Methodological findings were that the discrete-time method led to a successful reduction in the continuous-time person-period dataset; however, it was necessary to experiment with the length of time intervals in order to have the widest interval without influencing parameter estimates. The grouping according to covariates method worked best when there were, on average, a larger number of individuals per higher-level unit, there were few risk factors in the model and little or none of the risk factors were continuous. The Bayesian method could be favourable as no data expansion is required to fit the Weibull model in WinBUGS and time is treated as a continuous variable. However, models took a much longer time to run using MCMC methods of estimation as opposed to likelihood methods. This thesis showed that it was possible to use a re-parameterised version of the Weibull model, as well as a variance expansion technique, to overcome slow convergence by reducing correlation in the Markov chains. This may be a more efficient way to reduce computing time than running further iterations.

Evidence is presented to indicate that: a) The cuticular layer of the shell is rarely present as an even covering at any stage in the laying year. So, its role as a first line of defence is questionable. b) The shell membranes do inhibit bacterial transfer to some degree, even when they are structurally disrupted; however, if the challenge is great enough, then their function as effective barriers is reduced. c) In the absence of the shell membranes, Salmonella enteritidis Phage type 4 does not move freely across the shell, but it is either facilitated or inhibited in its passage by structural variation in the true shell, particularly at the level of the mammillary layer. Statistical data support in most instances a significant and positive correlation between the presence of structural defects and bacterial transfer. d) In a three tier battery system, a tier effect exists with respect to ease of translocation of microoganisms, with eggs from the top tier being more susceptible, i.e. structurally inferior. e) The results confirm earlier work that shell quality declines with age, and extends this finding to show that this morphological deterioration is accompanied by a decreased resistance to bacterial movement. f) Patent gas exchange pores, whilst obvious portals for bacterial ingress, are in this respect of secondary importance to structural defects within the shell. Evidence is also provided to substantiate the assumption that birds, irrespective of strain, display diverse shell structural quality. One of the strains evaluated (strain B) was structurally better than the other (strain A), at the beginning and middle of lay, and was also more capable of withstanding bacterial challenge in all three laying periods tested. 4. The housing system can influence shell quality; thus Barn and Battery eggs were structurally superior to their Range counterparts, at the end of lay. 5. The tagging of Salmonella with immunogold markers proved to be a valuable technique, which allowed a more precise localisation of the bacteria within the shell's ultrastructure, as viewed by the Scanning Electron Microscope (S.E.M.). This method gave support to other findings in this work, confirming that bacterial transfer was specifically encouraged by late fusion and alignment of the mammillae and pitting occurrences, with the cone layer probably implicated in the process of penetration in vivo. (now derestricted)

Outbreaks and sporadic cases of viral Infectious Intestinal Disease (IID) are a major public health issue resulting in significant morbidity and sometimes mortality each year. The economic costs associated are substantial. Laboratory diagnosis of viral IID is important as the many infectious and non-infectious causes cannot be reliably differentiated using clinical or epidemiological characteristics alone. An accurate diagnosis can aid patient management, infection control procedures and reduce health care costs by preventing unnecessary treatments, testing for alternative causes and hospital stay. It also aids public health surveillance. At the start of the research described in this thesis the West of Scotland Specialist Virology Centre (WOSSVC) used Electron Microscopy (EM) as the frontline test for outbreaks and sporadic cases of IID. However, although rapid on a small number of samples, this technique has been shown to be insensitive, laborious and is not suited to testing large numbers of samples. The research presented in this thesis sought to examine whether molecular diagnostic techniques such as conventional gel-based or real-time Polymerase Chain Reaction (PCR) assays could be a viable replacement for EM as the frontline test(s) for viral IID in a routine laboratory service of this type, and whether their implementation could bring benefits to the laboratory service in terms of improved rapidity, sensitivity and throughput. The aim was to adapt published PCR methods for use in routine diagnostic work rather than for research purposes, an approach that distinguishes this research from previous work in this area. In order to achieve this aim, the appropriate PCR techniques were first selected from the literature, based on a combination of clinical and laboratory requirements, and were adapted for use in the laboratory service. A series of laboratory experiments was then carried out in order to compare the sensitivity of the adapted methods to existing techniques such as EM and antigen detection assays (EIAs) and to other methods that emerged during the period of study including alternative PCR assays. Where found to be suitable, the selected PCR tests were implemented in the routine diagnostic service for viral IID. The effects of these changes on the laboratory service were then examined. The results show that since the introduction of molecular tests at WOSSVC for the detection of viral pathogens in cases of gastroenteritis the number of samples tested has risen steadily, as have the detection rates for each of the main viral causes of IID. Furthermore, this has been achieved at the same time as a substantial reduction in sample turn-around-times. Such improvements will have a positive impact in several areas of public health relating to viral IID and are discussed fully, including patient management, infection control and national surveillance.

This thesis offers an analysis of how conceptions of responsibility have affected social responses to HIV/AIDS. The central premise of this work is that how responsibility for the disease is presumed has a determining impact upon policy and individual reactions to the epidemic. This in turn influence the spread of the disease. This thesis also addresses how AIDS and its associated meanings provides and necessitates new ways of understanding social relations of responsibility. I begin with a theoretical exploration of dominant perspectives on responsibility through the development of two analytical categories: responsibility as freedom and responsibility as control. The first of these represents those approaches to responsibility that regard it as the condition that makes individual freedom possible. The second views all notions of responsibility as an inherently restrictive means of individual self-disciplining which only serves to protect the status-quo. In the successive case studies on health promotion materials, I-IIV testing policy and the criminalisation of HIV transmission, I develop a detailed analysis of the embeddedness of individual responsibility as promoted by the responsibility as freedom model, and of the accompanying critiques of those individualised approaches that some from the responsibility as control model. I then explore and alternative form of apprehending responsibility that transcends this abrupt dichotomy between freedom and control. Using the example of the 1 3th International AIDS Conference at Durban, I elaborate an intersubjective model of responsibility. In this framework, I propose an understanding of responsibility founded on social relations and the interconnectedness of social actors. This position also acknowledges the political struggles inevitably involved in attempts to bring about change, struggles which involve individuals, civil society, organisations and states.

Hospital-acquired infections (HAIs) are a big threat to the well-being of patients and place a heavy burden on hospital resources. The thesis provides the first attempt to apply agent-based simulation (ABS) to describe the transmission dynamics and evaluate the intervention policies of HAIs in general and Methicillin-resistant Staphylococcus aureus (MRSA) in particular. Based on the proposed taxonomy of potential methods for modelling HAIs, the relative advantages of ABS compared to other modelling methods are investigated. The comparison provides a theoretical justification to the use of ABS. The main methodological issues, including the representation of patient agents and the modelling of the transmission process, are discussed and a framework of applying ABS on HAI modelling is proposed. Guided by the framework, a MRSA model is built and validated using observed data from an empirical study. The model is more realistic and flexible than previous MRSA models and embeds intervention policies that have not been systematically studied such as the turnaround time and frequency of screening tests and the decolonisation treatment. Various interventions and influencing factors are systematically evaluated by formal experimental design methods including the fractional factorial design and the response surface design. The experimental results indicate that the use of rapid screening tests with shorter test turnaround time is the most effective policy to reduce MRSA transmission in the hospital setting. The introduction of admission and repeat screening is another effective policy; however, the effectiveness is not linear and may depend on patients’ lengths of stay. Providing more isolation facilities is also an effective policy but its effectiveness is significantly dependent on the efficacy of isolation. To demonstrate the potential and flexibility of ABS, the MRSA model is extended to include a competitive infection, to include multiple hospital units and HCW agents, and the wider community.

Statistical inference and model choice for partially observed epidemics provide a variety of challenges both practical and theoretical. This thesis studies some related aspects of models for epidemics and their inference. The use of the matrix exponential to facilitate exact calculations in the General Stochastic Epidemic (GSE) is demonstrated, most usefully in providing the exact marginal likelihood when infection times are unobserved. The bipartite graph epidemic is defined and shown to be a flexible framework which encompasses many existing models. It also provides a way in which a deeper understanding of the relation between existing models could be obtained. The Indian buffet epidemic is introduced as a non-parametric approach to modelling unknown heterogeneous contact structures in epidemics. Inference for the Indian buffet epidemic is a challenging problem, some progress has been made. However the algorithms which have been studied do not yet scale to the size of problem where significant differences from the GSE are apparent. Evidence confirming and demonstrating the importance of understanding the tail behaviour of proposals in importance sampling is presented. The adverse impact of heavy tailed proposals on the Grouped Independence Metropolis-Hastings (GIMH) and Monte Carlo within Metropolis (MCWM) algorithms is demonstrated. A new algorithm, the Kernel Metropolis Hastings (KMH), is proposed as an approximate algorithm for low dimensional marginal inference in situations where the GIMH algorithm fails because of sticking. The KMH is demonstrated on a challenging 2-d problem.

In the United Kingdom (UK), an estimated 107,800 people were living with HIV in 2013, of whom 55% were heterosexual men and women. Black African men and women accounted for the majority of heterosexuals living with HIV in the UK in 2013. In this PhD by prospective publication my research question is “How is the epidemiology of heterosexually-acquired HIV infection evolving, particularly among black Africans, in England, Wales and Northern Ireland?”. I conducted a quantitative analysis of national surveillance datasets and undertook literature searches. Most of my analysis was based on data from the three national HIV surveillance systems which constitute the HIV and AIDS Reporting System (New HIV Diagnoses database; Survey of Prevalent HIV Infections Diagnosed; CD4 Surveillance Scheme). I published the results of my analyses in six peer-reviewed papers between 2007 and 2014. My key findings were as follows: over the last decade an increasing proportion of black African heterosexuals born abroad but diagnosed with HIV in the UK acquired HIV whilst living in the UK; outward migration from the UK may explain why some black African heterosexuals were lost to follow-up from HIV care; the proportion of black African heterosexuals diagnosed late with HIV has not changed substantially; the uptake of HIV testing among black African heterosexuals has increased over time but remains low compared with that among MSM. To minimize the risk of HIV transmission and to maximise the benefits of earlier detection my key recommendation is to promote regular HIV testing among black African women and men in a range of healthcare and community settings in E,W&NI, particularly in primary care.