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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Association between active smoking, secondhand smoke and peripheral arterial disease

Lu, Liya January 2017 (has links)
Worldwide, cardiovascular disease (CVD) is the leading cause of death. It is widely accepted that both active smoking and exposure to secondhand smoke (SHS) are associated with CVD. About 20% of the global population smoke tobacco or tobacco-related products. The global prevalence of smoking is increasing, although it is decreasing in some high-income and upper middle-income countries. Globally, about a third of adults and 40% children are regularly exposed to SHS. According to the World Health Organisation (WHO), only 16% of the global population is protected by a comprehensive smoke-free legislation. Coronary heart disease (CHD), stroke and peripheral arterial disease (PAD) are all types of atherosclerosis and often co-exist in the same patients. Therefore, they share many common risk factors including cigarette smoking. However, previous epidemiological studies on CVD including those on cigarette smoking mainly focused on CHD and stroke and pay little attention to PAD. Evidence is increasing in support of the association between exposure to SHS and both CHD and stroke. In contrast, there is a paucity of studies on SHS and the risk of PAD. The overarching aim of this thesis was to collate the published evidence on the association between active cigarette smoking and PAD, and examine the association between exposure to SHS and PAD in the general population. This thesis starts with a systematic review on the association between active cigarette smoking, SHS and PAD undertaken using four databases: Medline, Embase, PubMed and Web of Science to identify existing published evidence up to 30 April 2012 (Chapter 2). Prior to the published studies contained in this thesis, there had been no meta-analyses on the association between active cigarette smoking and PAD and only two studies published on the association between SHS and PAD. Therefore, this systematic review was followed by a meta-analysis on the association between active cigarette smoking and PAD. This meta-analysis identified 55 studies: 43 cross-sectional, 10 cohort and 2 case-control. Of the 68 results for current smokers, 59 (86.8%) were statistically significant and the pooled odds ratio (OR) was 2.72 (95% confidence interval [CI] 2.28-3.21). Of the 40 results for ex-smokers, 29 (72.5%) were statistically significant and the pooled OR was 1.67 (95% CI 1.54-1.81). Active cigarette smoking significantly increases the risk of PAD, compared with never smokers. The magnitude of association between active cigarette smoking and PAD was greater in current smokers than ex-smokers. In contrast, prior to my studies in this thesis, only two studies on SHS were identified. Only one showed an overall association between self-report SHS and PAD in Chinese never smokers, with a clear dose-response relationship. The other study used serum cotinine as measure for SHS exposure and found neither an overall association nor a dose-response relationship but suggested a very high cotinine concentration as threshold. Chapter 3 examines the association between SHS exposure and PAD in adult non-smokers in Scotland. This chapter includes two cross-sectional studies using the Generation Scotland: Scottish Family Health Study (GS: SFHS) and the Scottish Health Survey (SHeS), and one retrospective cohort study using the record linkage of the SHeS. In the cross-sectional study using SFHS, PAD was measured using ankle brachial pressure index (ABPI) but SHS exposure was self-report. Of the 5,686 never smokers, 134 (2.4%) had PAD (defined as an ABPI < 0.9). Participants who reported overall high level of SHS exposure (exposed to ≥40 hours per week) were more likely to have PAD, compared with those who reported no exposure to SHS. After adjustment for potential confounders, the association between SHS and PAD persisted (adjusted OR 4.53, 95% CI 1.51-13.56, p=0.007), with suggestion of a dose-response relationship. In the other cross-sectional study using SHeS, SHS exposure was measured objectively using cotinine concentration but PAD was based on self-report symptoms of intermittent claudication (IC) using the Edinburgh Claudication Questionnaire. Of the 4,231 non-smokers (defined as self-reported non-smokers with a salivary cotinine concentration <15 ng/mL), 134 (3.2%) had IC. Participants with high exposure to SHS (cotinine ≥2.7 ng/mL) were at significantly higher risk of IC, after adjustment for potential confounders (adjusted OR 1.76, 95% CI 1.04-3.00, p=0.036). A dose-response relationship was suggested, whereby the risk of IC increased with increasing cotinine concentration. However, the association varied by age category. Participants aged <60 were more strongly associated with PAD. This may be explained by survival bias. For the third, retrospective cohort study in Chapter 3, I used record linkage of SHeS to Scottish Morbidity Record 01 (SMR01) records and death certificates to identify the first hospital admission/death following the SHeS in which PAD was recorded as the primary or secondary cause. Of the 4,045 confirmed non-smokers who were free of baseline IC were included. Over the follow-up period (mean follow-up 9 years), there were 568 deaths, none of which were coded as due to PAD, and 64 participants were hospitalised for PAD. High exposure to SHS was associated with increased risk of all-cause mortality (adjusted hazard ratio [HR] 1.42, 95% CI 1.09- 1.86, p=0.011) among all non-smokers and increased risk of incident PAD (adjusted HR 2.82, 95% CI 1.14-6.96, p=0.024) among male non-smokers. Increased cotinine concentrations at baseline were associated with increased risk of all-cause mortality, with a dose-response relationship. SHS contains both sidestream smoke, from burning cigarette tips, and exhaled mainstream smoke. Shortened telomere length is broadly viewed as a biomarker for biological ageing including atherosclerosis phenotypes such as PAD. Evidence is strong that active smoking increases telomere length attrition but whether such association occurs between SHS and telomere length is unknown. Therefore, Chapter 4 aimed to add to growing evidence that exposure to SHS is associated with disproportionately higher biomarkers of cardiovascular risk compared with active smoking and may accelerate normal biological ageing. This chapter includes two cross-sectional studies. The first study investigated the relationship between salivary cotinine and several preclinical cardiovascular biomarkers: C-reactive protein (CRP), high-density lipoprotein (HDL) cholesterol, TC/HDL cholesterol ratio and fibrinogen in 10,081 adults from the SHeS. CRP concentration and the TC/HDL cholesterol ratio increased, and HDL cholesterol concentration decreased with increasing cotinine concentration among both non-smokers and active smokers. There were step changes in the relationship between tobacco exposure and cardiovascular biomarkers at the interface of non-smokers exposed to SHS and active smokers. Non-smokers with high exposure to SHS had lower cotinine concentrations than light active smokers but comparable concentrations of CRP (p=0.709), HDL cholesterol (p=0.931) and the TC/HDL cholesterol ratio (p=0.405). Fibrinogen concentration was less clear-cut and only increased in moderate and heavy active smokers. The second study in this chapter explored the association between self-reported levels of SHS exposure and telomere shortening per annum using a subgroup of participants from the SFHS. Of the 1,303 non-smokers, telomere length decreased more rapidly with increasing age among participants with high level of SHS exposure, compared with both those with no exposure (adjusted coefficient -0.006, 95% CI -0.008- -0.004) (high vs no SHS: p=0.010) or low exposure (adjusted coefficient -0.005, 95% CI -0.007- -0.003) (high vs low SHS: p=0.005). In summary, there is now substantial evidence of an association between active cigarette smoking and PAD. / This thesis adds to the limited existing evidence on SHS as an independent risk factor for PAD. There was an overall association between exposure to SHS and PAD, with suggestion of a dose-response relationship. However, the association varied by age category. Individuals aged <60 were more strongly associated with the prevalence of IC. SHS was significantly associated with incident PAD only in men. This thesis further demonstrates that exposure to SHS carries a disproportionately higher cardiovascular risk than active smoking for a given level of smoke exposure. Telomere shortening per year of age may be an intermediate step between SHS and CVD including PAD. This also supports the association between SHS exposure and the atherosclerosis-related biomarkers, which play an important role in the pathophysiology of PAD. Further research is needed in the future to better understand the association between SHS and PAD, and the underlying mechanisms. The research in this thesis supports the need to protect the general public from exposure to SHS.
102

Ageing with HIV : an investigation of the health and well-being of older people in a rural South African population with a severe HIV epidemic

Nyirenda, Makandwe January 2014 (has links)
This study aims to describe the living and informal care circumstances of older people in an area of rural South Africa severely affected by HIV, and examine how those circumstances may influence the physical health, emotional well-being and survival of older people. Using longitudinal surveillance and cross-sectional survey data this thesis is built around four separate but related papers. Specific study objectives were to: 1) investigate household living arrangements and informal care (financial, physical or emotional assistance) by or towards older people in rural South Africa; 2) describe the self-reported health and emotional well-being status of older people by HIV status; and 3) examine the association between self-reported health, emotional well-being and informal care and mortality in older people. Surveillance data for 2005-2010 showed living arrangements remained stable, with over 85% of older people aged 60 years and above living in multi-generational households; over this period employment rates in both older and young people declined, but government grants receipt increased. Being co-resident with own children, household structure and size were important determinants of whether financial support flowed downward (from older to younger) or upward (from young to older person); while peer support (from one older person to another) was rare. Adjusting for age, marital status, education, place of residency and household socio-economic status, exchanges of financial resources in the study population are most likely to be downward or at best reciprocal (bidirectional with young people). Of the cross-sectional study participants (n=422) aged 50+, over 60% were care-givers (provided help with activities of daily living) to at least one adult (18-49 years) or child (below 18 years); around 84% (n=356) of older people were care-receivers; of whom over 92% (n=329) were receiving assistance with fetching water. Spouse, adult child, and grandchildren were the main sources of physical or emotional care for care-recipients. As expected health deteriorated with advancing age and women were less likely to be in good health. Further, care-giving was associated with improved functional ability but decreased emotional well-being. HIV-infected older participants reported better functional ability, quality of life and overall health state than HIV-affected (had an HIV-infected or HIV-related death of adult child) study participants. These differentials in health and well-being were also evident in mortality patterns over three years of follow-up. Mortality was higher among non-care-givers than in care-givers, in older people with poor self-rated health and in participants who had experienced a major depressive episode. Findings suggest there is an intricate relationship between living arrangements, informal care and health, emotional well-being and survival of older people in severely HIV-affected settings. More crucially, with the considerable resources devoted to HIV Care and Treatment programmes, uninfected older persons may be highly vulnerable to poor health. A multifaceted intervention to improving older people’s health and well-being is urgently required.
103

An exploration of consultant doctors' hand hygiene : practice and perspectives

Westbury, J. January 2012 (has links)
Hand hygiene is considered the cornerstone of infection prevention practice, but previous studies demonstrate one group of healthcare professionals, doctors, have not achieved good levels of compliance in comparison to other staff groups. The aim of the research was to examine consultant doctors‟ practice and perspectives of hand hygiene, exploring their perceptions as leaders and role models, so as to identify strategies to improve compliance. The study design was based on naturalistic inquiry, focussing on the social constructions of participants. Nineteen consultant doctors were observed during hospital ward rounds using both a national audit tool to assess hand hygiene compliance and recording of field notes. These same consultants, plus a further two, were interviewed individually to elicit their views. Data from the 21 interviews and field notes were analysed qualitatively using thematic content analysis. Observations demonstrated high levels of hand hygiene compliance for high risk and medium risk activities, with low levels of compliance for low risk activities. Thematic content analysis revealed a strong belief by consultant doctors in the value of hand hygiene. However, a perceived conflict between political and scientific drivers of hand hygiene promotion gave rise to confusion, frustration and a lack of engagement that created barriers to leadership and acting as a role model. Differing guidelines and audit tools that did not address levels of risk compounded the matter. However, consultant doctors offered various recommendations to resolve the issues. Compliance with hand hygiene by consultant doctors is dependant on perceived levels of risk. To promote leadership and role modelling it is critical to engage consultant doctors, understand their views, employ their recommendations and recognise they are motivated by evidence-based rationales for practice rather than political mandates. The findings, conclusion and recommendations of the research study have significant implications for addressing the shortfalls of the hand hygiene agenda in clinical practice and for the engagement of consultant doctors.
104

Development of a quality of life measure for adults with bilateral cochlear implants

Buhagiar, Roberta January 2012 (has links)
Cochlear implants (CI) provide a sense of hearing to people who are severely or profoundly deaf. A single CI (unilateral) has been shown to improve quality of life (QoL) substantially and clinical practice is evolving towards two per patient (bilateral), although the incremental benefit for QoL has not yet been established definitively. There is a need for self-report measures designed specifically to quantify benefits for QoL in patients who receive a second CI, in order to evaluate the relative benefits of unilateral and bilateral implantation. The aim of the present study was to develop and validate such a measure that is suitable for adults. The sample consisted of patients from the United Kingdom National Health Service who have received two CI sequentially. The study was based on the ‘Rolls Royce’ approach. A retrospective open-ended questionnaire and face to face interviews were carried out in the first stage. Categories from the qualitative data obtained from the responses were identified and these were the foundations on which a close-ended questionnaire was developed. In the second stage, face validity, test-retest reliability and correlations of each item were investigated and amendments were made to the questionnaire items to reflect these results. In the last stage participants were asked to fill in the amended questionnaire together with another three existing QoL questionnaires (generic and disease-specific ones). These results showed that the questionnaire under development is valid and reliable. Responses from the participants also gave an insight into the changes that they experienced as a result of receiving a second CI. The main reports were related to experiences of increased confidence and independence levels as a result of having bilateral CI. Improvement in listening in group situations and localisation ability were also noted. Changes in participant experience were evident when they filled in the questionnaire under development and also the Speech, Spatial and Qualities of Hearing questionnaire. Better understanding of changes in QoL after receiving a second CI will help professionals to understand the benefits of bilateral implantation in adults from the users’ perspectives. This is considered to be important when deciding whether patients should be advised to opt for unilateral or bilateral CI in the future. This knowledge will also help prospective patients understand the practical benefits and limitations of one or two cochlear implants.
105

Modelling patient length of stay in public hospitals in Mexico

Guzman Castillo, M. January 2012 (has links)
This thesis is concerned with the modelling of patient length of stay in public hospitals in Mexico. Patient length of stay is the most commonly worldwide employed outcome measure for hospital resource consumption and performance monitoring. Most of the hospitals around the world use average length of stay as starting point for resource planning. However average estimates frequently gives non-accurate results due to the high variability of the length of stay data. The reason for such high variability may be attributable to the diversity in the patient population and the environment where the patient is treated. Through a systematic review of the literature on methods and models in the field of calculating and predicting patient length of stay, this research highlights the areas of opportunity and research gap from previous studies and practices, and proposes the use of finite mixture models to approximate the distribution of length of stay. Also, these models are proposed as the foundation of more sophisticated models designed to include the internal and external factors associated with LoS. In this context, the thesis proposes three different approaches to explore such factors: individual-based approach, group-based approach and multilevel group-based approach. These interrelated approaches allow a better understanding of the diversity in the patient population and enable length of stay predictions for individual patients, and for cohorts of patients within and between hospitals. In addition, this research is built and evaluated using data from all types of patients treated at two public hospitals operating in Mexico. It is the consideration of the full case-mix of these healthcare facilities that gives this research its unique nature.
106

The role of consultant midwife : an exploration of the expectations, experiences, and intricacies

Robinson, A. January 2012 (has links)
Consultant nurse and midwife roles, with the expectations of significantly moving forward the professions in relation to practice development, effective leadership and quality care provision, have been a major UK policy initiative since 2000. Whilst consultant nurses have received much attention, consultant midwives have been relatively little researched. This study aimed to explore the intricacies of the consultant midwife role. Using an in-depth qualitative case study design, the roles of eight consultant midwives across eight NHS Trusts in England were studied. Data were collected via in-depth interviews with consultant midwives, their heads of maternity services and consultant obstetricians; additionally, the consultant midwives were observed in practice and documentary evidence (their job descriptions) were examined. Data were analysed thematically and aggregated, revealing three dominant themes related to clinical wisdom, taking control and shaping the future. Findings showed that the consultant midwife is in a position of power, built on a foundation of clinically acquired wisdom, transformational leadership skills and a belief in woman centred care, essential to a profession fit for the future. Individually and collectively, the consultant midwives conveyed a passion for their role, whilst aware of the demands of their position. Their impact lay in relation to the way they used their experience, skills and understanding, to undertake complex roles in practice, juggling responsibilities to effect change and improve services for childbearing women and their families. Their strength was born out of acquired knowledge and expertise, as leaders and as role models, influencing not only practice but the midwives of the future. This thesis provides the first in-depth exploration of the consultant midwife role and as such greatly strengthens the hitherto limited evidence base. As well as focusing on the particular aspects of day-to-day consultant midwifery it also gives detailed recommendations for further development of the role organisationally.
107

The (in)visibility of older people in the international development discourse

Lipman, Valerie January 2011 (has links)
Older people are the world’s fastest growing population group. By 2050 eighty per cent of older persons will live in what are now developing countries. There is established and growing evidence of the difficulties families in developing countries are experiencing in providing adequate support for their older members. This thesis explores how international development is responding to the interests of older people. The research examines how older people are represented in international development discourse and illustrates the impact of this on practice. This is informed by a comparative analysis with the progress of women in development. A critical discourse analysis of a corpus of texts from intergovernmental agencies illustrates the degree of visibility of older people in the development discourse. A case study of the work of inter-government organisations in West Bengal, India, shows how this can impact on grassroots activity. An original conceptual framework is introduced which aligns the dominant development paradigms with the dominant perspectives on older people emerging from this research. To the best of my knowledge this is the first research study to consider the (in)visibility of older people in international development discourse and to look at its implications on policy and practice. It highlights that a concentration of development resources at one end of the age spectrum to increase life expectancy is being met with an absence of planned support to meet the consequences when people successfully reach old age. The research further shows that when visible, older people are generally viewed as a homogeneous group in need of support and care, and not as citizens able to contribute and participate in development. The research illustrates a connection between global discourse and local practice in relation to older people and indicates a need for further studies to assess the extent of the links and to examine how local practice could inform the international development discourse.
108

Thinking about patients and talking about persons in critical care nursing

McLean, Christopher Duncan January 2012 (has links)
Nursing scholarship and healthcare policy set an expectation that nurses should think about patients as persons. Nevertheless, the literature reveals that critical care nurses can struggle to perceive patients as persons, and thus suggests they may think about patients in different ways. This thesis presents the findings of an ethnographic study undertaken within one critical care unit in the United Kingdom which examined how critical care nurses do think about patients. A purposive sampling strategy recruited 7 participants representing both experienced and inexperienced critical care nurses. Data were collected over a period of 8 months during 2006 to 2007, and primarily comprised the field notes from 92 hours of participant observation supplemented by 13 tape recorded interviews. Data analysis was influenced by Foucault and Goffman and adopted the perspective of linguistic ethnography. Analysis revealed that all participants thought about patients in seven distinct ways: as ‘social beings’, as ‘valued individuals’, as ‘routine work’, as a ‘set of needs’, as a ‘body’, as ‘(un)stable’ or as a ‘medical case’. Accounts of participants’ practice revealed that they had a tacit understanding that these different ways of thinking related to aspects of one coherent whole, but no one way of thinking could be characterised as thinking about this ‘whole person’. Nurses could only think about one aspect of the patient at a time. Nurses’ practice was not guided or explained by their thinking about patients as persons, but rather expert practice was characterised by nurses’ fluid and appropriate movement between different ways of thinking about patients. When participants talked about their practice it was evident that these nurses could only legitimately talk about themselves as giving care to persons. Participants characterised some of the ways in which they had to think about patients as impersonal, and this actively hindered these nurses from describing or reflecting upon elements of their practice. There is therefore conflict and dissonance between nurses’ expectation that they should think about patients as persons, and the fact that delivering nursing care requires them to think about patients in different ways. The development of future critical care nurses will require practitioners and educators to recognise that nurses think about patients in different ways, and that expert practice is characterised by the clinical wisdom which enables nurses to think about patients in ways which are appropriate to the moment. Nurse scholars and educationalists should therefore avoid claims to a unique professional knowledge base which suggest to nurses that some ways of thinking are always inappropriate or inherently reductionist. Instead, there is a need for scholars and policy makers to articulate a vision of person centred care clearly, and in ways which avoid constructing dissonance between nurses’ ideals, and the ways in which they do and must think about patients.
109

An exploration of dietary patterns and the relationship with obesity in the Malaysian population

Ali, Asma January 2014 (has links)
No description available.
110

Breath by breath analysis of breathing pattern in health and disease : a potential outcome measure for breathing retraining?

Lo, Wai January 2013 (has links)
Analysis of breathing pattern can quantify parameters of breathing such as rate, volume, timing and regularity/rhythmicity. This information can be useful to compare breathing patterns in those healthy and with disease, under different experiment conditions (such as rest versus activity) and to monitor changes over time. In this research, respiratory inductive plethysmography (RIP) was used to record breathing patterns in a group of healthy subjects and a group of severe asthma patients. RIP is a leading technology for ambulatory monitoring of breathing, but traditional RIP devices suffered from poor signal quality under such conditions due to movement of the sensor. Several authors have also raised doubts about the existing calibration methods for RIP which can lead to inaccurate estimation of breathing parameters. During the first phase of the programme, an instrumented garment (LifeShirt®) which had RIP embedded within was tested for its validity in comparison to a pneumotachograph (PT). The first study sought to validate the measurements obtained from the LifeShirt ®against PT when calibrated with a published but yet to be tested method for breath by breath analysis and to address the limitations of existing calibration methods. Eleven healthy individuals took part in this first study. Breathing patterns were simultaneously monitored by the LifeShirt ® and the PT during thirty minutes of rest and twenty minutes of exercise. Parameters of tidal volume, expiration time and tidal volume variability were recorded and compared between devices. The analysis from the first study demonstrated that RIP recorded proportionate changes of tidal volume and expiration duration relative to PT during quiet breathing and exercise. Mean tidal volume and expiration duration between devices was strongly correlated for rest and exercise. No statistical difference in tidal volume variability was observed between devices during either period. Significant differences in expiration duration between devices were observed in all participants at rest but not during exercise. Results of this first study demonstrated that valid breath by breath analysis using RIP without PT was feasible. This is clinically advantageous due to simplicity of set-up for RIP. In the second phase, measurement of breathing patterns was made in severe asthma patients with the LifeShirt® alone during thirty minutes of rest. It intended to add new knowledge with regards to the breathing patterns within this small population as compared to the healthy population. Ten healthy individuals and ten patients diagnosed with severe asthma took part in the second study. Breathing parameters of tidal volume, inspiration time, expiration time, end tidal carbon dioxide levels, tidal volume variability and end tidal carbon dioxide levels variability were recorded by the LifeShirt®. The analysis of the second phase shown no evidence that breathing pattern parameters could differentiate between the severe asthma patients and healthy volunteers in our small study. The symptoms of hyperventilation found more commonly in the severe asthma group were not associated with differences in breathing pattern parameters. However, considerable differences were found between individuals. This suggests the existence of individuality in breathing patterns between individuals. Such findings raised doubts as to whether there is a group ‘pattern’ that is common within the severe asthma population or within the healthy population. This programme calls for a change in paradigm to consider breathing patterns as an unique individual ‘trait’ rather than as a group characteristic.

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