Self-care is considered a means of meeting the challenge of providing care to patients with long-term conditions. However this has not achieved widespread penetration in the UK, the reasons for which are unclear. This research examined one area of self-care in depth - self-monitoring of oral anticoagulation therapy. The aim was to derive the requirements for an anticoagulation patient self-monitoring service from an analysis of the drivers for, the benefits of, the barriers to, and the challenges of establishing this service from the perspectives of key stakeholders – patients, healthcare professionals and healthcare managers. Qualitative and quantitative techniques - interviews, semi-structured questionnaire survey and focus groups – were used to gain an in-depth understanding of their views. From triangulated results, the candidate requirements for an anticoagulation self-monitoring service were derived, presented in Donabedian’s framework: structure, process and outcome. Most of these requirements were then validated through a pilot self-monitoring service. All stakeholder groups supported anticoagulation self-monitoring. However, financial, clinical and legal barriers were identified. 53% of surveyed patients were willing to undertake self-monitoring. However, only 17% of respondents felt able to purchase a coagulometer, a significant barrier. Lack of confidence in the ability to self-test was also demonstrated. Healthcare staff welcomed self-monitoring as a way to increase capacity and support evolution in the healthcare landscape. There were concerns about affordability to all stakeholders, the potential for increased clinical risk through sharing care with patients, and a fear of litigation compounded by a lack of clarity in the medicolegal position. Patient education and support were essential requirements, to prepare the patient, and on an ongoing basis. Primary care professionals felt expert support was essential for them to deliver this service. A definitive set of service requirements is proposed, and the implications of this research for other long term conditions discussed.

The aims of this thesis were two-fold. Firstly, to develop a robust method to create a fully integrated, national surveillance dataset for human immunodeficiency virus (HIV) infections by linking records from three independent, national HIV case reporting systems. Secondly, to apply statistical techniques, more commonly used in cohort study research, to the integrated dataset to yield more of the potential from the constituent information and increase the public health utility of the data. This demonstrated that an integrated dataset can reduce missing information in each surveillance system and improve information use by combining different data that was previously available only in separate databases. Using the integrated dataset, I achieved the following: accounted for missing information; described the frequency of CD4 count measurements and associated factors; determined characteristics associated with late diagnosis and consequent mortality; estimated the national incidence of acquired immunodeficiency syndrome (AIDS) and death and the influencing factors; assessed information about the date of starting therapy for each individual; and assessed factors associated with immune defence recovery after the start of treatment. These analyses will be/have been integrated into national surveillance processes as appropriate and used to publish academic papers. Lessons have been learnt for surveillance methodology with regards sharing information and ensuring that data are representative of the whole population. The large size, wide coverage and prospective nature of the integrated dataset mean that national (and local) policy decisions can be based on information that reflects the national picture rather than unrepresentative and time-bound studies. The dataset also has the power to unpick differences within small population groups. For example, evidence about late diagnoses and mortality has been used to promote the need for earlier HIV diagnosis and is updated annually and used to target local needs and to monitor improvements.

This thesis proposes a novel computer assisted detection framework to analyse airway shape change and to detect signs of paediatric pulmonary tuberculosis (TB). The method can accurately distinguish TB patients with airway involvement, from non-TB patients using CT scans. This model is also applied to X-ray radiographs to segment the airways. As a first step, a CT airway segmentation algorithm is proposed, and then evaluated as part of the EXACT’09 airway segmentation challenge. Algorithms are then implemented to extract the airway centreline, detect branch points and label each airway branch. A number of cases had the appearance of complete obstruction in some bronchi, and a method is presented to identify and segment beyond these obstructions. A statistical shape model is developed using airway shape variation, which requires correspondence between airways. Thus, a method to register regions of the airway tree is proposed. This method generates landmarks on the airway surface. Using these landmarks, a template mesh is then aligned to each airway by thin-plate-spline warp and local vertex alignment. This develops a corresponding surface mesh representation for each airway that can be used for statistical analysis. A statistical model of the variation of local regions of the airway is constructed and features derived from this are used to train a classifier to detect abnormal airway variation. The method is able to accurately detect TB in unseen cases. It is also compared to second method based on automated bronchi measurements. Finally, a method is developed that uses the previous 3D model to segment the airways in 2D radiographs. This uses an optimisation algorithm to fit the 3D model to image features in the radiograph. These methods create novel tools for airway analysis and have wider applications in medical imaging.

SCUBA diving is inherently dangerous. Anecdotal reports suggest that risks may be exacerbated by diver behaviour, particularly tobacco smoking. This thesis reports findings from an internet survey of tobacco use, health and attitudes to risk taking conducted amongst UK members of the Professional Association of Diving Instructors in 2006. The main aims of the study were to assess smoking prevalence and factors associated with tobacco use compared to the UK population and to explore the health impact of smoking on divers, to determine the need for prevention measures in this group. After adjusting for socio-demographic factors, divers’ cigarette smoking prevalence (p<0.001) and consumption (p<0.001) were found to be lower than the UK population, although non-cigarette smoking prevalence was higher (p<0.001). Everyday risk taking scores were significantly associated with cigar or pipe use (p = 0.037) and higher cigarette consumption (p = 0.046) and dependence (p = 0.011) in current smokers. Divers with a professional recreational diving qualification who currently smoked had higher cigarette consumption (p = 0.001) and dependence (p = 0.001) compared with their non-professionally qualified peers. Recreational SCUBA divers were less likely to report poor general health than the UK population, but current cigarette smoking was significantly associated with poorer self-assessed health in divers (p = 0.006) after controlling for socio-demographic factors. After adjustment for confounding variables, current cigarette smoking was significantly associated with the occurrence of panic attacks (p = 0.014), which was significantly associated with lung problems (p = 0.016), and cigarette consumption was significantly associated with the frequency of diving-related illness (p = 0.037). In conclusion, although cigarette smoking prevalence and daily cigarette consumption were significantly lower in divers compared with the UK population, both were found to be associated with poorer health in important ways.

Fat and lean mass have important implications for adult health and physical functioning, but few studies have examined their determinants. This thesis used a life course perspective to examine how explanatory factors across life relate to adult measures of fat and lean mass. The MRC National Survey of Health and Development was used—a British birth cohort study originally comprised of 5362 babies born in March 1946. At 60–64 years, 746 males and 812 females had fat and lean mass measures taken using dual energy X-ray absorptiometry. Linear regression was used to examine associations between prospectively ascertained explanatory variables (socioeconomic position, measures of growth, and physical activity) with these masses. Lower childhood and adult socioeconomic position, greater weight gains in childhood and adolescence (7-20 years), and lower current physical activity levels (measured objectively and by self-report) were all associated with higher fat mass, with evidence in females of cumulative benefits of leisure time physical activity across adulthood (36 to 60–64 years) in leading to lower fat mass. Higher childhood (females only) and adult (both sexes) socioeconomic position, higher birth weight, greater weight gain from birth to 20 years, and physical activity participation across adulthood were all associated with higher lean mass; associations with socioeconomic position and physical activity were found after adjustment for fat mass. Associations between lower childhood socioeconomic position and higher fat mass were partly mediated by weight gain from 7–20 years; associations with higher fat and lower lean mass were partly mediated by leisure time physical activity measures. Factors operating in both early and adult life were associated with adult fat and lean mass. These factors could be potential targets for public health strategies which seek to reduce fat mass and increase lean mass in the population.

Female levels of obesity in low- and middle-income countries (LMICs) are rising. Obesity prevalence has been the greatest in high socio-economic status (SES) groups, but recent evidence suggests a changing pattern with the prevalence of obesity rising rapidly among lower SES groups and exceeding the former - a reversal of the social gradient of obesity. However, inconsistencies in the gradient by SES indicator have put the reversal into question. Using nationally representative surveys, the thesis: 1) examines the time variation in the SES-obesity association splitting SES into two components; and 2) tests the hypothesis that education protects against the obesogenic effects of improved material circumstances through cognitive skills and their influence on media exposure and dietary behaviour. Egypt (~40% female obesity prevalence) is investigated using Demographic and Health Surveys data. Changes in the SES-obesity association over the period 1992-2008 are examined including the separate and joint effects of education and material circumstances on obesity. Then, Egypt is compared with countries of different levels of economic development: Benin, Nigeria, India, Jordan, Peru, Colombia (DHS data) and China (Four-Provinces survey data). Finally, literacy, TV exposure and sweet snack use are investigated as mediators. All estimates are adjusted for age group, area of residence, and number of children using multivariate logistic regression. The findings showed variation over time and by country consistent with the reversal of the social gradient. Education significantly modified the association between material circumstances and obesity at middle levels of country income. There was evidence that literacy and TV exposure may mediate this inter-relationship but the study power limited inferences on dietary behaviour. The findings support the possibility that education drives the reversal of the social gradient of female obesity and that cognitive skills may be more important than material circumstances in preventing female obesity. Thus, investments in education could be viewed as preventive medicine.

In the UK substantial numbers of new HIV diagnoses are within migrant African communities. A continuing feature of HIV in this population is the late presentation to HIV services. This dissertation sets out to explore HIV testing among Africans in the UK, the factors associated with late presentation to HIV services, and the extent of HIV acquisition within the UK in African communities. The main focus of the thesis is the ‘study of newly diagnosed HIV among Africans in London’ (the SONHIA study), which combined qualitative and quantitative methods in a multi-centre study. The thesis begins with the work undertaken in preparation for SONHIA. It presents a literature review to provide epidemiological, cultural and historical background. Next is an analysis of the 2nd National Survey of Sexual Attitudes and Lifestyles to explore the factors associated with HIV testing among black Africans in Britain. Finally, the findings from in-depth interviews with key informants to identify the issues affecting utilisation of HIV services for Africans in Britain are presented. The SONHIA study consisted of survey of 269 Africans newly diagnosed with HIV. All respondents self-completed a questionnaire linked to clinical records, and 26 in-depth interviews with a purposively selected sub-sample were performed. The findings show that Africans are accessing services but clinicians are failing to use these opportunities for preventive and diagnostic purposes with regards to HIV infection. HIV presentation patterns appear governed by factors linked to the characteristics of, and response to, the HIV epidemic operating within people’s sociocultural networks. UK acquisition of HIV in this population appears substantially higher than acknowledged by national surveillance data, with a quarter to a third of HIV possibly acquired in the UK. The qualitative findings provide contextual understanding of the factors contributing to late presentation. They highlight the central role of HIV-related stigma and discrimination in influencing HIV testing behaviours. Failings within the health care system offer insight as how clinicians can better address HIV in the future. The key findings are summarized and contextualised with the literature and the current socio-political climate. The study’s limitations are addressed, and the thesis concludes with the public health and policy implications of the study.

Background: In 2005 Colombia adopted the national Millennium Development Goal (MDG5) target of 75% modern contraceptive prevalence rate (CPR) by 2015. Important gains have been achieved with respect to living conditions, education and health indicators in recent decades but inequalities within the country remain to be addressed. Methods: The aim was to analyse socioeconomic inequalities in women’s ‘current non-use of contraception’ using the six Colombian Demographic and Health Surveys (DHS). A multidimensional approach to socioeconomic position was implemented. Absolute and relative socioeconomic inequalities were analysed using the Slope Index of Inequality (SII) and Relative Index of Inequality (RII). The interplay between level of education and Public capital with respect to contraceptive non-use was examined. Individual and contextual effects were investigated using a multilevel approach. Results: National prevalence in current non-use of contraception between 1986 and 2010 decreased from32.6% to 22.9%. Nationally, absolute inequalities narrowed but relative inequalities did not decline. Women with less than primary education had not met the CPR target in 2010 in urban (30.9%) and rural (41.4%) areas respectively. Absolute inequalities narrowed in urban areas but relative inequalities persisted in urban and rural areas. Gradients in contraceptive non-use with respect to household wealth were stronger among women in rural than in urban areas. The impact of level of education on contraceptive non-use was relatively weak among women in households and within communities with high Public capital compared to low Public capital. Municipality ethnic composition had an effect on women’s contraceptive non-use over and above individual and community characteristics. Conclusion: Colombia reached the national CPR target ahead of time. However, the persistent socioeconomic gradients in non-use of contraception by household wealth and education indicate the need to go beyond country averages and individual level determinants to monitor urban and rural socioeconomic inequalities and contextual effects on women’s contraceptive behaviour.

In this thesis we examine the overlooked issue of vertical equity in health care delivery. This principle requires that individuals with unequal needs receive appropriately unequal treatment. Most analyses of equity in health care delivery focus only on horizontal equity, i.e. the principle of equal treatment for equal needs. Therefore, the aim of this thesis is to assess and refine the techniques to investigate vertical inequity, and to offer evidence about vertical equity in the English health care system. The extent of inequalities in health is first investigated. We find persistent inequalities in health in England. We then illustrate the methods widely used in the literature to explore horizontal inequity in health care and highlight a major limitation; these studies ignore the possibility that the estimated differential treatment received by individuals with different needs is inappropriate. In order to identify the methods used to date to measure vertical equity we review the empirical literature. The most comprehensive techniques identified focused on the socioeconomic dimension of vertical inequity. We illustrate these techniques and suggest an extension to this measure that takes into account the full distribution of needs in a population. We apply our suggested methods to measure inequity in individual level and in area level health care provision in England. The optimal variation of health care with variation in needs is estimated based on subgroups less likely to be affected by unmet needs. The findings of this thesis indicate that there is vertical inequity in detriment to socioeconomic deprived groups and, to a larger extent, in detriment to those with larger needs. We show that including vertical inequity aspects may lead us to draw different conclusions about the nature and extent of inequity. Therefore, conclusions about inequities in health care are extensively being made on the basis of incomplete information.

Although many lives are saved in intensive care, patients frequently fail to make a good recovery. In addition to physical weakness and cognitive impairment, patients suffer from clinical anxiety, depression and PTSD. The aim of this PhD was to establish the prevalence of poor mental health after intensive care and identify clinical, psychological and socio-demographic risk factors. First I carried out a systematic review of post-ICU psycho-social outcomes but found the quality of studies was variable and few consistent risk factors were identified. I subsequently conducted a prospective cohort study of 157 intensive care patients who were assessed for mood, stress, delirium and memory in the ICU. Clinical and socio-demographic data were recorded. At three months, 64% completed valid measures of PTSD, depression and anxiety, and socio-economic circumstances (SEC). Incidence of mood disturbance, delirium and physical stress in the ICU were 78%, 66% and 77% respectively. At three months, prevalence of PTSD was 27.1% (95%CIs: 18.3, 35.9%), depression 46.3% (95%CIs: 36.5, 56.1%) and anxiety 44.4% (95%CIs: 34.6%, 54.2%). A total of 55% of patients had at least one outcome. PTSD was predicted by number of organs supported, drug groups used and sepsis bio-markers. Strongest clinical predictors were days of sedation (PTSD), benzodiazepine usage (depression), inotropes (anxiety) and steroids (better physical HRQL). SEC was a risk factor for depression, anxiety and mental HRQL. Psychological predictors including ICU mood, stress, delirium and memories were highly correlated with outcomes and partially mediated the relationships between clinical factors and outcomes. A qualitative study of 17 patients with intrusive memories of ICU at three months revealed patients had highly disturbing hallucinatory flash-backs or distressing recurring images of bleeding, choking, tubes and pain. The PhD highlighted the need to reduce ICU stress and identified modifiable risk factors that could inform clinical interventions to help patients.