Patient-reported outcomes (PROs) produce meaningful information about patient-perceived health status reported directly by patients. Routine collection of PROs data is particularly important in chronic conditions, such as heart failure (HF). Major cardiovascular societies and regulatory agencies encouraged PRO inclusion in randomized controlled trials (RCTs), but PROs remain underutilized as a key outcome in these studies. In this systematic review, we aimed to evaluate temporal trends and explore trial characteristics associated with PRO inclusion in HF RCTs published in high-impact medical journals. We also assessed the quality of PRO reporting against the Consolidated Standards of Reporting Trials PRO extension. We found that over half of HF RCTs included a PRO. The proportion of RCTs with PROs increased significantly since 2000. A number of RCT characteristics such as multicentre; medium-sized (n = 51-250 participants); trials coordinated in Central and South America; and that tested health services, devices or surgery, exercise and rehabilitation interventions were independently associated with higher odds of PRO inclusion. The quality of PRO reporting was modest, with better reporting in RCTs with PROs a primary or co-primary endpoint. Consistent PRO inclusion and high-quality reporting are necessary to increase the utility of these findings by patients, clinicians, and health care policy makers. / Thesis / Master of Science (MSc)

The structural damage after the Christchurch earthquake (2011) led to extensively damaged facilities that did not collapse but did require demolition, representing more than 70% of the building stock in the central business district. These severe economic losses that result from conventional seismic design clearly show the importance of moving towards resilience-based design approaches of structures. For instance, special reinforced masonry shear walls (SRMWs), which are fixed-base walls, are typically designed to dissipate energy through the yielding of bonded reinforcement while special detailing is maintained to fulfill ductility requirements. This comes at the expense of accepting residual drifts and permanent damage in potential plastic hinge zones. This design process hinders the overall resilience of such walls because of the costs and time associated with the loss of operation and service shutdown. In controlled rocking systems, an elastic gap opening mechanism (i.e., rocking joint) replaces the typical yielding of the main reinforcement in conventional fixed-base walls, hence reducing wall lateral stiffness without excessive yielding damage. Consequently, controlled rocking wall systems with limited damage and self-centering behavior under the control of unbonded post-tensioning (PT) are considered favorable for modern resilient cities because of the costs associated with service shutdown (i.e., for structural repairs or replacement) are minimized. However, the difficulty of PT implementation during construction is challenging in practical masonry applications. In addition, PT losses due to PT yielding and early strength degradation of masonry reduce the self-centering ability of controlled rocking masonry walls with unbonded post-tensioning (PT-CRMWs). Such challenges demonstrate the importance of considering an alternative source of self-centering. In this regard, the current study initially evaluates the seismic performance of PT-CRMWs compared to SRMWs. Next, a new controlled rocking system for masonry walls is proposed, namely Energy Dissipation-Controlled Rocking Masonry Walls (ED-CRMWs), which are designed to self-center through vertical gravity loads only, without the use of PT tendons. To control the rocking response, supplemental energy dissipation (ED) devices are included. This proposed system is evaluated experimentally in two phases. In Phase I of the experimental program, the focus is to ensure that the intended behavior of ED-CRMWs is achieved. This is followed by design guidance, validated through collapse risk analysis of a series of 20 ED-CRMW archetypes. Finally, Phase II of the experimental program evaluates a more resilient ED-CRMW is evaluated, which incorporates a readily replaceable externally mounted flexural arm ED device. Design guidance is also provided for ED-CRMWs incorporating such devices. / Thesis / Doctor of Philosophy (PhD)

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No description available.

Controlled substance use, particularly among the rising elderly population, places these patients at a much higher risk of falls, injuries, and hospitalization. This study examines the association between preinjury controlled substance prescription and clinical outcomes of older adults after a ground-level fall. A total of 5,930 patients were included. Their home medication list was analyzed to record active opioids, benzodiazepines, narcotics, or other substances defined as controlled according to the Drug Enforcement Agency. Almost half (45%) of the patients were taking controlled substances. Sixty-seven percent of those were females. Total hospital days, Injury Severity Score (ISS), and mortality outcomes were not significantly different between groups. However, intensive care unit (ICU) days, days on mechanical ventilation (MV), and discharge destination were significantly different for patients taking controlled substances versus those not taking controlled substances. Patients taking controlled substances were more likely to be discharged to short- and long-term care facilities versus patients not taking controlled substances (P≤0.001).

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Background and Objectives: Missing participant data are likely to bias the results of randomized control trials (RCTs) when the reason for missingness is associated with status on the outcome of interest. Unlike dichotomous MPD in RCTs, which have been thoroughly investigated, knowledge regarding continuous MPD in RCTs is much more limited. Our objectives were 1) using an adapted checklist, to assess the reporting quality of simulation studies comparing methods to deal with continuous MPD; 2) identify optimal methods proposed by biostatisticians and tested in simulations studies for continuous MPD in RCTs; 3) evaluate how authors report MPD, and how they plan and conduct analyses to deal with MPD in RCTs. Methods: We conducted two systematic surveys. The first identified methods papers published till 2015 January that compared statistical approaches to deal with continuous MPD in RCTs using at least one simulation. In this sample, we considered both the quality of reporting and the results. The second survey identified a representative sample of individual RCTs published in 2014 in core journals reporting the results of at least one continuous variable addressing a patient-important outcome. Results and conclusion: Our survey identified important limitations in reporting quality of simulation studies that compared statistical approaches to deal with continuous MPD, particularly in the reporting of simulation procedures. Only one of 60 studies reported the random number generator used and none reported starting seeds or failures during simulation. Less then half reported software used to perform simulation (41.7%) or analysis (48.3%), and only 4 (5%) reported justification of number of simulations. When facing continuous MPD in RCTs, results of simulation studies demonstrate that trialists seeking optimal approaches may choose robust regression or mixed models and avoid using last observation caring forward. Continuous MPD frequently occurs in RCTs and the extent is typically substantial (median greater than 10%). Methods sections in trial reports typically do not provide adequate detail on how they dealt with MPD in their primary analysis. Among methods actually implemented to deal with MPD, most authors use only available data, thus excluding MPD from the analysis. Seldom do investigators apply statistical approaches to impute or taking into account of MPD nor conduct sensitivity analysis to address the impact of it. A comprehensive knowledge synthesis summarizing current available statistical approaches and its relative merits, as well as the current used methods in RCTs provide clear implications on how the practise of using methods to handle continuous MPD should shift in individual RCTs. Trialists should use mixed models and robust regressions and avoid using last observation caring forward method. / Thesis / Doctor of Philosophy (PhD)

Experiments were carried out on the solidification of iron-manganese alloys containing sulphur and carbon. The alloys were solidified under controlled conditions in a travelling furnace constructed especially for the investigation. Qualitative and quantitative metallography and electron-probe microanalysis were used to determine the solidification structure, dendrite arm spacings, solute concentration profiles and inclusion compositions. The results were interpreted in the light of existing knowledge and concepts especially developed for the purpose of this investigation. / Thesis / Doctor of Philosophy (PhD)

<P> This thesis is concerned with the investigation of the diffusion controlled reaction between MgO and β-quartz in the temperature range 1200 - 1450 °C in wet and dry atmospheres. The reactions were studied by placing known faces of quartz crystals in direct contact with Mg0 powder, heat treating them, and then investigating the cross sections. The product layer was investigated by both reflected light and thin section metallography, electron - microprobe and X- ray diffraction. Using Wagner's and Schmalzried's ideas on solid state reactions, a theoretical model for the diffusion controlled formation of silicates was developed. With this model, a mechanism for the diffusion controlled formation of forsterite from MgO and β-quartz was advanced. </P> / Thesis / Master of Science (MSc)

Importance: Evidence from randomized controlled trials (RCTs) is required to guide treatment of critically ill children. Unfortunately such evidence is not always available. Objectives: To describe the RCT research enterprise in pediatric critical care — the evidence and the process of creating it, along with problems and some solutions. Methods: To meet these objectives I undertook a series of 5 related studies. First a scoping review to describe the output of the research enterprise. Second, a social network analysis of coauthorship patterns to describe the community of researchers who produce this evidence. Third, a survey to investigate the importance of RCTs in clinicians’ decision-making. Fourth, a survey of trialists to identify barriers and facilitators of high quality RCTs. Fifth, a qualitative interview study to identify acceptable, feasible and effective strategies to improve the evidence available from RCTs in pediatric critical care. Results and conclusions: The number of RCTs in pediatric critical care is increasing but there is a preponderance of small, single-centred RCTs focusing on laboratory or physiological outcomes that are often stopped early because of feasibility problems or futility. The research community is highly fragmented and highly clustered. Experienced trialists identified approaches to improve the pediatric critical care research enterprise, including building a sense of community and ensuring key training and relevant practical experiences for new investigators. Because of the barriers that researchers face and their ethical obligation to undertake trials that are feasible and make a meaningful contribution to advancing the care of critically ill children, individuals and groups must take an active role in building a healthy research community. Only by changing how we function as a research community can we train the next generation of investigators and undertake the type of trials needed to improve the care of critically ill children. / Thesis / Doctor of Philosophy (PhD) / Evidence from randomized controlled trials (RCTs) is required to guide treatment of critically ill children. Unfortunately such evidence is not always available. My objectives in this thesis are to describe the RCT research enterprise in pediatric critical care — the evidence and the process of creating it, along with problems and some solutions. To meet these objectives I undertook a series of 5 related studies: to identify and describe the RCTs, describe how researchers collaborate, understand how clinicians use RCTs, identify barriers and facilitators of conducting high quality RCTs, and understand how we can improve the evidence available from RCTs in pediatric critical care. We found that the number of RCTs is increasing but there are opportunities to improve the methods, outcome measures, and quality of reporting. We identified strategies that researchers can adopt to facilitate the rigorous RCTs that are needed to improve the care of critically ill children.