The effectiveness of speed limits has been the subject of considerable debate over the years. In most cases in the past, speed limits have been changed because of a single factor (e. g. improving the safety of road traffic or saving energy). In this thesis an attempt has been made to evaluate the consequences of changing a speed limit using cost-benefit analysis which formed the principle objective of this study. The scope was confined to motorways and similar high-quality roads operating under free-flow traffic conditions where speed limits were believed to be most effective. To achieve the main goal, the effect of the speed limit on the mean speed of traffic was investigated which was the second objective of the study. The third objective was to find the effect of the speed of traffic, and especially the mean speed of traffic, on the frequency and severity of personal injury accidents. There was a need to investigate these two relationships as the literature was not consistent on these relationships. A hypothesis was proposed to achieve the second objective. This was tested by defining criteria that had to be met for each of the data collection sites and measuring the speed of vehicles. There were II sites in Tyne & Wear, England and 14 sites in the State of Bahrain. A statistical analysis was applied to the data collected. It was found, from both sets of data, that speed limits had a positive effect on the mean speed and the eighty-fifth percentile speed of traffic. Linear and non-linear (multiplicative) models were developed for each set of data. In addition to the speed limit, the trip length and the length of the section were shown to affect significantly the mean speed of traffic. The amount of change in the mean speed of traffic varied between the models tested but, generally, for every 4 to 5 km/h change in the speed limit the mean speed of traffic changed by, about, I km/h. In a similar way, a hypothesis was proposed to pursue the third objective. Criteria were established for the selection of suitable data collection sites and for the types of accidents. 9 sites were selected in Tyne & Wear and 10 sites in the State of Bahrain. Data was drawn from a5 year set of accident records in Tyne and Wear and a four year set in the State of Bahrain. A statistical analysis was applied to the data. The set of data from Tyne & Wear revealed no significant relationship between the mean speed of traffic and the frequency of accidents but the speed differentials affected the frequency of the personal injury accidents. The data from Bahrain showed that both the mean speed of traffic and the speed differentials of vehicles affected the frequency of the personal injury accidents. No significant relationships were found between the speed of vehicles and the severity of the personal injury accidents. The principle objective of the study was achieved by applying cost-benefit analysis to the consequences of changing the speed limit for a hypothetical typical section of road. The components of cost were the cost of travel-time, the vehicle operating cost, and the cost of accidents. No monetary values were assigned to the environmental effects so it was not possible to include them in the cost-benefit analysis but they were acknowledged. Any changes in air pollution and noise annoyance due to a change in the mean speed of traffic following a change in a speed limit were likely to be small and were not considered in the study. The significance of the uncertainty in the frequency and severity of personal injury accidents in relation to the mean speed of traffic was studied using 'break-even analysis'. Generally, it was believed that lowering the speed limit on motorways and similar high-quality roads would produce negative benefits, even if the frequency and severity of personal injury accidents decreasedw ithin expectedr anges. Increasing the speed limits would produce positive economic benefits but the conclusion was less firm than the previous case. Sensitivity analysis was applied to the variables used in the cost-benefit analysis. It was found that the net benefits were most sensitive to the estimation of the effect of the speed limits on the mean speed of traffic, the initial mean speed of traffic in the base year of the assessment, the travel-time cost, the changes in the frequency of the personal injury accidents, and changes in the number of fatal injury casualties per average personal injury accident as the speed limit varied (i. e. in descending order for most speed limits). The ranking of these variables differed as the speed limit was changed.

published_or_final_version / Nursing Studies / Master / Master of Nursing

published_or_final_version / Public Health / Master / Master of Public Health

published_or_final_version / Community Medicine / Doctoral / Doctor of Philosophy

Ageing is a progressive impairment of function causing decreased defense against environmental challenges and increased risk of many diseases. The development of ageing and ageing-related diseases might be attenuated by nutrients such as carotenoids and polyunsaturated fatty acids. In the present study, for the first time, two nutrient-rich marine microalgae, namely Haematococcus pluvialis (HP) and Schizochytrium mangrovei (SM) were studied for their anti-ageing effects both in vitro and in vivo. Results of nutritional profile analysis confirmed that HP is rich in astaxanthin (AX) (978.9 μg/g). Using rat adrenal medulla pheochromocytoma (PC12) cells as an in vitro model, AX exhibited significant protective effects against oxidative stress induced by H2O2 or amyloid β-peptide (Aβ). To testify whether AX conveys such effects to HP, the anti-ageing property of HP was subsequently investigated on Drosophila melanogaster. In the group of SODn108 mutant fruit flies, lifespan elongation effect was observed, where HP may play as a complement of the defective endogenous antioxidant system to extend the lifespan and ameliorate the age-related decline of locomotor function. On the other hand, a long-term intake of HP (20 mg/mL) induced early mortality of wild type fruit flies, which was associated with the decreased enzymatic activities of CuZn-superoxide dismutase (SOD1) and Mn-superoxide dismutase (SOD2) as well as mRNA down-regulation of SOD1, SOD2, and Catalase (CAT). Further study showed that HP supplementation contributed to the defense of wild type OR fruit flies against chronic but not intensive oxidative stress. The observed ‘bifacial effect’ could be resulted from ‘hormesis’ responses, suggesting the therapeutic instead of the preventive potential of HP against ageing-related diseases. Another microalga SM was found to contain abundant docosahexaenoic acid (DHA) (53 mg/g). The in vitro studies showed that SM failed to protect PC12 cells under H2O2-induced oxidative stress due to its poor anti-oxidative activity. However, from in vivo studies, the SM supplementation significantly extended the lifespan of both wild type and SODn108 mutant fruit flies and ameliorated the age-related decline of locomotor function. Further studies revealed that the observed activities were associated with the mRNA up-regulation of endogenous stress-defending genes such as SOD1 and SOD2, as well as the down-regulation of methuselah (MTH) gene. It has been proposed that antioxidants may protect DHA against oxidative damage. To determine whether there is a synergistic effect for HP and SM, a mixture of these two algal samples was evaluated for its effects on the lifespan of D. melanogaster. Results showed that the wild type fruit flies fed with the mixture had no elevated survival rate, tentatively suggesting that the increased nutritional complexity may trigger elevated metabolic rate and lead to shortened lifespan. In conclusion, results of the present study demonstrated the anti-ageing properties of nutrient-rich microalgae both in vitro and in vivo, suggesting SM possesses the potential to be used as a preventive diet supplementation, while HP may be a suitable candidate as therapeutic agents. Based on these findings, the health benefits of nutrient-rich microalgae for the elderly as well as patients with ageing-related diseases were proposed. / published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

Haemostasis is an important aspect in neurosurgical operations for the achievement of good outcome. Bipolar coagulation is an extensively used haemostatic technique in modern neurosurgery but it may also cause iatrogenic brain trauma due to thermal injury. Published studies on coagulation-induced brain injury on a histological level are, however, limited. The present study aimed at investigating the extent of inflammatory and glial responses caused by different settings of bipolar coagulation using an animal model. It also investigated whether and how pre-operative treatment with dexamethasone or progesterone, both known to have neuro-protective effects, would modulate gliosis and macrophage infiltration induced by bipolar coagulation. The study consisted of two parts. The first part investigated the astrocytic and macrophage responses after bipolar coagulation at different power settings. 45 Sprague-Dawley rats received craniotomy, followed by bipolar coagulation at different power output settings (mock operation as control, 20W and 40W) over the rat cortex for a standardized duration of two seconds. On day 3, day 7 and day 28, brain sections were assessed by immunohistochemical staining for GFAP (astrocytes) and ED1 (macrophages). Quantification of outcome by random field cell counting under light microscopy was performed. The second part of the study used another 45 male Sprague-Dawley rats, divided into three treatment groups: Group 1 received the vehicle agents only (Control); Group 2 received progesterone 20mg/kg; Group 3 received dexamethasone 1 mg/kg. All treatments were given intraperitoneally two hours before craniotomy. The animals received bipolar coagulation at 40W for a standardized duration of two seconds. On day 1, 3 and 7, brain sections were assessed by immunohistochemical staining for GFAP and ED1. Quantification of outcome by random field cell counting under light microscopy was performed. T2-weighted magnetic resonance imaging for the animals on day 3 was also performed. The results showed that bipolar coagulation was associated with significant glial and inflammatory responses that correlated with power output. Progesterone and dexamethasone were both effective in reducing the glial hypertrophy and macrophage infiltration associated with bipolar coagulation. Dexamethasone had an additional advantage of reducing brain oedema and cavity formation. The findings suggested that progesterone and dexamethasone could be further explored as potential protective and/or remedial agents for bipolar coagulation-induced brain trauma sustained during neurosurgical procedures. / published_or_final_version / Surgery / Master / Master of Research in Medicine

Older adults are particularly vulnerable to the development of pressure ulcers (PUs) as a result of skin changes and reduced mobility (Knox, Anderson & Anderson, 1994; Russell et al., 2003). This is associated with diminished quality of life, longer hospitalisations and increased morbidity and mortality (Margolis et al., 2002).In view of the high incidence of PUs (grade 1-4) occurring in elderly patients in acute care, a systematic review of related studies was conducted in August 2011. The optimal frequency and methods of repositioning are described in the literature. With well-designed implementation and evaluation plans, the proposed repositioning guidelines are likely to reduce the incidence of PUs (grade 1-4), while in turn lessening the healthcare burden and preserving patients’ quality of life. Pilot testing, a trial run to test the feasibility of the innovation, will be carried out in the proposed medical ward, and training provided to all staff before the intervention. To proceed with the change, the intervention must be cost-effective and beneficial to all stakeholders. Outcome evaluation determines the number of goals achieved by the innovation and to what degree, and is very important (Melnyk & Fineout-Overholt, 2005).The PU incidence (grade 1-4) is expected to be different after the implementation of the innovation. / published_or_final_version / Nursing Studies / Master / Master of Nursing

Background Myocardial Infarction (MI) is one of the major diseases which cause death in the world nowadays. In Hong Kong, 27.7 persons per 100,000 population died from AMI during the years 2007 to 2009. The rate for recurrent MI is also very high and the mortality rate is even higher for recurrent MI cases than first MI attack. Meanwhile, modern lifestyles and convenience brought about by advancements in technology have led to unhealthy lifestyles which is a risk factor for recurrent MI. Prevention of recurrent MI has become highly important and a worldwide public health issue. Patient education is the process by which health professionals provide information to patients or the public aiming to enhance their awareness and, therefore, alter their unhealthy behavior in order to improve their health status. Even nowadays, patient education is a common approach to disease prevention and health promotion in developed countries. Currently, many developed countries use patient education for disease prevention and health promotion. Many studies have investigated the effect of patient education on recurrent MI prevention resulting from proper behavioral change, and some decreases have resulted in recurrent MI after giving patient education. However, there is a gap in the current literature regarding the specialized meta-analysis in the evaluation of effectiveness of patient education conducted within three months or earlier. In other words, the efficiency of patient education to prevent recurrent MI has seldom been assessed. Although there have been a few systemic reviews about patient education in the past, the focus of these studies was not on recurrent MI, but obesity and diabetes. In addition, they discuss the issues in a qualitative manner, and omit calculations of the relative risk or summarized odds ratio. Therefore, this meta-analysis aims to generate statistics on the evaluation of the positive impact resulting from early patient education on recurrent MI prevention. Aim The current study aimed to assess the effect of early post-MI education in preventing the recurrence of myocardial infarction. Objective The current systematic review aimed to evaluate the relation between the occurrence of recurrent MI, which is evidenced by hospitalization, in addition to consultation with medical professionals, and the provision of early patient education. Method Studies were identified through searching e-databases including MEDLINE (Ovid), PUBMED, Cochrane library and EMBASE. Two reviewers searched the databases independently. Keywords included “recurrent heart attack”, “recurrent myocardial infarction”, “post MI education”, “prevention of myocardial infarction”, “cardiac rehabilitation on MI” when searching the databases. Only studies fulfilling the inclusion criteria were chosen in this meta-analysis. Randomized control trials were selected and included in meta-analysis after the screening and filtering process. Other study methods such as case control study and cohort study were not included in this meta-analysis. All studies selection included in this meta-analysis had to follow strictly the PRISMA 2009 guideline. Quality assessments were also performed by using CONSORT 2010 checklists. Results Eight randomized controlled trials were selected for this meta-analysis. The meta-analysis evaluated the effect of receiving early patient education on prevention of future recurrence of MI by comparing with control subjects. Patients who received early patient education showed a reduction of risk of recurrent myocardial infarction by 3% to 100%; the summarized relative risk of the interventional group was 0.80compared with the control group. This means there resulted a 20% reduction in recurrent MI. Conclusion Early patient education was shown to have a positive effect on the prevention of recurrent MI in this meta-analysis. Compared with the usual care in today’s hospital and medical system, we should provide more early patient education to patients with myocardial infarction for recurrent MI prevention. In light of this meta-analysis, I recommend the government to invest more funds and manpower in patient education at both hospital and clinical levels. / published_or_final_version / Public Health / Master / Master of Public Health

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are together known as venous thrombo-embolism (VTE), one of the most common complications after surgery and trauma injury. In the case of critically ill patients, it is also a significant medical and financial burden, associated with high mortality and morbidity. In recent years, much evidence has come to light showing that DVT prophylaxis can effectively reduce DVT, and it has been incorporated into various evidenced-based guidelines (Geerts et al., 2008; Nicolaides et al., 2006). The objectives of this study are to examine, through a comprehensive literature review of published studies, the effectiveness of various means of DVT prophylaxis aimed at reducing DVT, and to develop an evidence-based guideline for the use of DVT prophylaxis in surgical intensive care unit (ICU) settings. Keywords related to DVT prophylaxis were used in conducting the search in electronic bibliographic databases like MEDLlNE, CINAHL, PubMed and the Cochrane Library. A total of 110 articles were identified, and seven studies fulfilled the inclusion criteria of the study. Data from the seven studies have been extracted to form tables of evidence; the qualities of the studies were then rated, and the levels of evidence assigned according to SIGN 50: A guideline developer’s handbook (Network, Harbour & Forsyth, 2011). Three studies attained a higher level of evidence with strong methodological design and demonstrated a statistically significant reduction in the incidence of DVT. The implementation potential of DVT prophylaxis was examined in terms of target setting, target audience, transferability of findings, feasibility and cost-benefit ratio. And it was found that the development of evidence-based guidelines for DVT prophylaxis was feasible, cost-beneficial and transferable in current settings. The findings of the seven reviewed studies have been translated into an evidence-based DVT prophylaxis guideline. The main focuses of the guideline are the choice of prophylaxis used with surgical ICU patients and the strategies for improving adherence and prophylaxis monitoring. Combined pharmacological and mechanical DVT prophylaxis is recommended for ICU patients who are at high risk of DVT. For patients with active bleeding or high risk of bleeding, mechanical prophylaxis like intermittent pneumatic compressor (IPC) or gradual compression stocking (GCS) should be used first, followed by a review for pharmacological prophylaxis when the risk of bleeding has decreased. In addition, routine assessment of thrombosis and bleeding risk for high-risk ICU patients and regular checking of fitting and functioning of the DVT prophylaxis are recommended. An implementation plan consisting of communication, pilot and evaluation plan was developed. A 12-month programme including communication with stakeholders, marketing of the innovation, training of frontline staff, a five-week pilot study and implementation of the guideline followed by evaluation will be carried out. In the evaluation, programme effectiveness was assessed in terms of patient outcome (e.g. incidence of DVT), process outcomes (e.g. level of knowledge related to DVT, compliance with the guideline and level of staff satisfaction) and system outcome (e.g. financial cost reduction). / published_or_final_version / Nursing Studies / Master / Master of Nursing

Hypothermia at birth is strongly associated with mortality and morbidity in preterm infants. Unfortunately, infants are prone to hypothermia immediately after birth. A large proportion of preterm infants, especially those of gestational age at less than 30 weeks, experience different levels of hypothermia. A frequently used possible preventive measure is the application of an occlusive wrap immediately after birth. However, no systematic review on this preventive measure supports its translation into practice. This dissertation aimed to evaluate the current evidence on the application of occlusive warp for preterm infants. Four electronic databases, Cochrane Library, PubMed, CINAHL, and Medline, were searched. Eight studies met the inclusion criteria of this dissertation. Data were extracted and the quality of the included studies was evaluated by the Scottish Intercollegiate Guidelines Network (SIGN). Six studies were graded as high quality studies and showed that occlusive wrapping significantly prevented the incidence of hypothermia among the preterm infants smaller than 30 weeks. An evidence-based Superwarm guideline was developed, which was deemed to be transferable to the local setting of neonatal intensive care unit with similar target clients and philosophy of care as with those in the identified studies. Also, the proposed innovation was considered to be feasible after examination of staff competency, resources, and approval methods. The potential benefits to preterm infants, nurses, and also the hospital were high, and risks to the patient were minimal. The estimated set-up cost including manpower and consumable cost was $1,720, and the running cost was also $1,720 per year. A 12 -month implementation program scheduled including communication with stakeholders, training to the frontline nurses, and a pilot of the guideline. Patient outcomes will be measured by admission temperature, temperature one hour after admission, and mortality rate. Healthcare provider outcomes include compliance rate, workload, acceptance of the proposed guideline, job satisfaction, knowledge, and skill enhancement in thermoregulation of the preterm infants. The quality of patient care was also considered in the system outcomes. Guideline effectiveness will be evaluated by the increase in admission temperature, nurse and physician satisfaction, and controlled program expenditure. / published_or_final_version / Nursing Studies / Master / Master of Nursing