Queueing theory has often been applied to study communication and service queueing systems such as call centers, hospital emergency departments and ride-sharing platforms. Unfortunately, it is complicated to analyze queueing systems. That is largely because the arrival and service processes that mainly determine a queueing system are uncertain and must be represented as stochastic processes that are difficult to analyze. In response, service providers might be able to partially capture the main characteristics of systems given partial data information and limited domain knowledge. An effective engineering response is to develop tractable approximations to approximate queueing characteristics of interest that depend on critical partial information. In this thesis, we contribute to developing high-quality approximations by studying tight bounds for the transient and the steady-state mean waiting time given partial information. We focus on single-server queues and multi-server queues with the unlimited waiting room, the first-come-first-served service discipline, and independent sequences of independent and identically distributed sequences of interarrival times and service times. We assume some partial information is known, e.g., the first two moments of inter-arrival and service time distributions. For the single-server GI/GI/1 model, we first study the tight upper bounds for the mean and higher moments of the steady-state waiting time given the first two moments of the inter-arrival time and service-time distributions. We apply the theory of Tchebycheff systems to obtain sufficient conditions for classical two-point distributions to yield the extreme values. For the tight upper bound of the transient mean waiting time, we formulate the problem as a non-convex non-linear program, derive the gradient of the transient mean waiting time over distributions with finite support, and apply classical non-linear programming theory to characterize stationary points. We then develop and apply a stochastic variant of the conditional gradient algorithm to find a stationary point for any given service-time distribution. We also establish necessary conditions and sufficient conditions for stationary points to be three-point distributions or special two-point distributions. Our studies indicate that the tight upper bound for the steady-state mean waiting time is attained asymptotically by two-point distributions as the upper mass point of the service-time distribution increases and the probability decreases, while one mass of the inter-arrival time distribution is fixed at 0. We then develop effective numerical and simulation algorithms to compute the tight upper bound. The algorithms are aided by reductions of the special queues with extremal inter-arrival time and extremal service-time distributions to D/GI/1 and GI/D/1 models. Combining these reductions yields an overall representation in terms of a D/RS(D)/1 discrete-time model involving a geometric random sum of deterministic random variables, where the two deterministic random variables have different values, so that the extremal waiting times need not have a lattice distribution. We finally evaluate the tight upper bound to show that it offers a significant improvement over established bounds. In order to understand queueing performance given only partial information, we propose determining intervals of likely performance measures given that limited information. We illustrate this approach for the steady-state waiting time distribution in the GI/GI/K queue given the first two moments of the inter-arrival time and service time distributions plus additional information about these underlying distributions, including support bounds, higher moments, and Laplace transform values. As a theoretical basis, we apply the theory of Tchebycheff systems to determine extremal models (yielding tight upper and lower bounds) on the asymptotic decay rate of the steady-state waiting-time tail probability, as in the Kingman-Lundberg bound and large deviations asymptotics. We then can use these extremal models to indicate likely intervals of other performance measures. We illustrate by constructing such intervals of likely mean waiting times. Without extra information, the extremal models involve two-point distributions, which yield a wide range for the mean. Adding constraints on the third moment and a transform value produces three-point extremal distributions, which significantly reduce the range, yielding practical levels of accuracy.

Electronic health records (EHRs) led to improvements in patient safety, care delivery, and efficiency; however, they have also resulted in significant increases in documentation time. EHR documentation burden, defined as “added work (e.g., documentation) or extraneous actions (e.g., clicks) performed in the EHR beyond that which is required for good clinical care”, has been linked to increased medical errors, poorer patient outcomes, reduced care quality, cognitive overload, and ultimately, burnout among clinicians. Relative to other clinical practice settings where patient flows are more predictable and of lower intensity, emergency department (ED) clinicians report markedly higher workload. Furthermore, EHR implementation research in the ED indicates that incongruities between EHR design and usability and the clinical workflow may intensify clinician workflow fragmentation. In our prior work, we identified workflow fragmentation, which we define as task switching, as one potential approach for evaluating documentation burden in ED practice settings. Yet, no standardized, scalable measures of documentation burden have been developed. Despite shortcomings, there have been increasing efforts to leverage information from EHR event logs as an alternative to direct clinical observation methods in evaluating user-centric behaviors and interactions with health information technology systems. Using EHR event logs, this dissertation aims to advance the study of evaluating burden by investigating EHR-mediated workflow fragmentation as a measure of EHR documentation burden among physicians and registered nurses (hereinafter interchangeably referred to as “clinicians”) in the ED. First, I review the literature on the existing quantitative approaches employed for measuring clinician documentation burden in clinical practice settings. Next, I explore EHR factors perceived to contribute to clinician documentation burden as well as the perceived role of workflow fragmentation on clinician documentation burden in the ED. Lastly, I investigate data-driven approaches to abstract clinically relevant concepts from EHR event logs for studying EHR documentation burden—culminating into a computational framework to evaluate ED clinician documentation burden in the context of cognitive burden. Collectively, the work conducted in this dissertation contributes computational methods that are foundational for investigating clinician documentation burden measurement at scale using EHR event logs, informed by current evidence and clinician perspectives, and grounded in theory.

Rapid changes in the healthcare environment increase the need for nurse practitioners to be motivated, knowledgeable and skilled in order to ensure quality patient care. Accident and emergency units are challenging environments and by ensuring that nurse practitioners work in an enabling environment, they should be motivated, skilled and knowledgeable and be able to think critically to enhance their own professional growth and emancipated practice. This in turn may increase the nurse practitioners’ job satisfaction, which in turn encourage job retention and may influence patient outcomes positively. A journey towards a shared vision namely “emancipatory practice development” was undertaken in an accident and emergency unit of a Level III public hospital. Following the diagnosis of an emergency situation, action research was applied to change the perceived toxic environment to an enabling environment. The study was conducted within the critical social theory paradigm and descriptive, explorative and contextual in nature. Both qualitative and quantitative approaches were utilised. Throughout the action research for practitioners project, collaboration enhanced the emancipation of the nurse leaders, as key drivers of the process, as well as the nurse practitioners. Short and long-term actions were planned, implemented and amended based on observations and reflection following each cycle of the project. During this process a toxic environment was changed to an enabling environment, in which nurse practitioners were retained and additional spin-offs followed. Guidelines for the application and implementation of the process as utilised in this study were compiled to guide others who experience similar challenges. / Health Sciences / D.Litt. et Phil. (Health Studies)

International mass sports gatherings like the FIFA (Federation Internationale de Football Association) World Cup Soccer and Olympics can cause great challenges to local healthcare systems and emergency medical services. History has shown that disasters do occur during these events, whether on a small or large scale. Disaster Management Practitioners from the public health perspective widely recognize that poor planning and a range of other underlying factors, create conditions of vulnerability. These result in insufficient capacity or measures to reduce hazards’ potentially negative consequences. The eThekwini District has to be prepared in the event of a mass disaster. Pre-empting and planning for disasters will lead to the safety and security of our citizens. The aim of this study was to undertake a baseline survey (in a total number of eleven public sector hospitals) to assess the state of hospital readiness, medical preparedness, and emergency care in preparation for the 2010 FIFA World Cup Soccer in the eThekwini District. A general assessment tool in the form of a standard questionnaire, and a walkthrough visit with a checklist, was used to collect data. There is no previous study conducted at the eThekwini District to assess requirements for an international event in terms of a mass disaster. South Africa is a developing country, and this was the first time any developing country had hosted a sporting event on such a large magnitude thus there are no international standards on sports disaster management by any other developing countries to generalise to eThekwini District. The current disaster management operational plan that is being used for the World Cup is based on a United Kingdom integrated management philosophy tool. The study herein adopted a public health approach and incorporates the Yokohama Strategy within its tool along with the use of HMIMMS and MIMMS in the assessment of the clinical criteria. The perceived minimum requirements suggested by the hospitals and a Provincial Task Team, from the Provincial Health Disaster Management office, was used as a guideline. The study showed that although disaster plans and policies are in situ, there still exists a need for resources to be directed toward skills training, attraction and retention of healthcare professionals, revitalisation of emergency and theatre areas and the commissioning of more isolation units. The results of the study would enable the District Office to note any shortcomings and lack of resources in public sector hospitals. The study outcome would be important for the implementation of any strategic planning to aid the hospitals in preparation for mass disasters that may occur during the 2010 FIFA World Cup Soccer. / Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2010.

Rapid changes in the healthcare environment increase the need for nurse practitioners to be motivated, knowledgeable and skilled in order to ensure quality patient care. Accident and emergency units are challenging environments and by ensuring that nurse practitioners work in an enabling environment, they should be motivated, skilled and knowledgeable and be able to think critically to enhance their own professional growth and emancipated practice. This in turn may increase the nurse practitioners’ job satisfaction, which in turn encourage job retention and may influence patient outcomes positively. A journey towards a shared vision namely “emancipatory practice development” was undertaken in an accident and emergency unit of a Level III public hospital. Following the diagnosis of an emergency situation, action research was applied to change the perceived toxic environment to an enabling environment. The study was conducted within the critical social theory paradigm and descriptive, explorative and contextual in nature. Both qualitative and quantitative approaches were utilised. Throughout the action research for practitioners project, collaboration enhanced the emancipation of the nurse leaders, as key drivers of the process, as well as the nurse practitioners. Short and long-term actions were planned, implemented and amended based on observations and reflection following each cycle of the project. During this process a toxic environment was changed to an enabling environment, in which nurse practitioners were retained and additional spin-offs followed. Guidelines for the application and implementation of the process as utilised in this study were compiled to guide others who experience similar challenges. / Health Sciences / D.Litt. et Phil. (Health Studies)

This thesis is a case analysis of the nature of delays in emergency room admissions and the effects on ambulance dispatching and availability as it occurred in Southern California.

This dissertation consists of three essays in health economics concerned with measuring the determinants of health care resource utilization and health. In the first chapter, I study entry barriers in healthcare provider markets. In the U.S., proponents of regulatory entry barriers called CON programs claim that they reduce waste by limiting "unnecessary" entry. I examine CON programs in the dialysis industry, where their effects on market structure, access, health, costs, and welfare are poorly understood, and where patients are sensitive to access and quality. I combine quasi-experimental policy variation in low population areas with a structural model of patient preferences to find that marginal entrants improved access significantly, reduced hospitalization rates, and generated for patients the utility value of traveling 275-344 fewer miles per month; but there is evidence that they contributed even more to fixed costs. Using policy variation throughout North Carolina, I also find evidence that the NC dialysis CON program created a mechanism through which incumbents could block potential entrants by expanding in tandem with their local patient populations. Taken together, my findings suggest that stronger regulatory entry barriers in low population areas may raise total welfare at patients' expense---but they also amplify concerns that CON programs dampen competition statewide. In the second chapter, I study an empirical framework commonly used in health economics research to measure the impact of an event over time using observational data: the event study. Dating back to at least Snow (1855), event studies have been used in health economics research to study mortality, health care utilization, health insurance enrollment, provider competition, and much more. Under no anticipation and parallel trends assumptions, difference-in-differences are known to identify the event's average treatment effect on the treated when units experience one event at most. In this paper, I introduce a new event study framework to accommodate settings where units may experience multiple events. I introduce a matching estimator which consistently and transparently estimates the average treatment effect on the treated of a single event under generalizations of the conventional no anticipation and parallel trends assumptions. I show that the matching estimator is equivalent to a weighted least squares estimator for a particular set of weights. I also introduce a parallel pre-trends test which can be used to scrutinize these assumptions in the usual sense. Finally, I demonstrate in a series of Monte Carlo simulations that the estimator and parallel pre-trends test work well for a wide range of treatment effects, including dynamic, non-stationary, and history-dependent treatment effects. In the third chapter, I study when and why emergency departments initiate ambulance diversions, and what happens to diverted patients. Efficiently distributing scarce healthcare resources among patients with time sensitive healthcare needs and uncertain arrival rates is a hard problem. When an emergency department gets too full, ED managers sometimes request that incoming ambulances reroute their patients to alternative destinations. While such ambulance diversions can sometimes help an overcrowded ED manage its caseload, it can also harm incoming patients and reduce systemwide EMS responsiveness. In detailed administrative records cataloging when, where, and why diversions occur, as well as who got diverted, I document that diversions commonly last exactly 1 hour, approximately 4 hours, and exactly 8 hours (indicating that managerial frictions may directly affect ED availability); that diverted patients have different characteristics than non-diverted patients (including potentially more severe symptoms); and that diverted patients spend 65% longer on the road to the hospital than non-diverted patients. I also find that diversions often occur not only because of crowdedness, but also because of hospital systems failures. I identify directions for future research.

Patient satisfaction dimensions have a wide ranging and significant impact on organizational performance in the healthcare industry. In addition, the Centers for Medicare and Medicaid Services Hospital Value Based Purchasing (HVBP) Program links patient satisfaction to Medicare reimbursement, putting millions of dollars at risk for health systems. A gap in the literature exists in the exploration of how a patient's experience in the emergency department affects their satisfaction with inpatient services. In a multiple regression analysis, the relationship between HVBP Patient Experience of Care and hospital level factors including emergency department wait times are explored. Results indicate a statistically significant relationship between hospital level factors and standardized measure of patient satisfaction with a moderate adjusted effect size (p= <.0001, R2 adjusted= 0.184). Emergency department wait times post physician admit orders were most salient in predicting patient satisfaction scores (rs2= 0.434, β= -0.334, p= <.001). Recommendations to improve emergency department wait times include focusing on key decision points and implementation of electronic systems to support the movement of admitted patients out of the emergency department as quickly as possible.

The study aimed to investigate the implementation of customer care at the Casualty Department of Edenvale Regional Hospital in Gauteng Province. The research was conducted using a qualitative case study approach, which sought to gain deeper understanding of the impact of customer care in the hospital’s Casualty Department from the employees’ point of view. Data was collected from 16 purposively selected respondents using semi-structured interviews and document analyses were interpreted by the researcher to give voice and meaning to the assessment topic. Data was analysed using the Content Analysis framework and six themes emerged from the data analysis: (1) High expectation levels from the community; (2) Quality of patient care; (3) Lack of resources; (4) Malfunctioning equipment; (5) Compromised safety and security; (5) Strategies to improve customer care; and (6) The effect of policies and guidelines on the quality of services rendered. The study revealed that the surrounding community that is served by the Edenvale Hospital’s Casualty Department had high expectations which the hospital was unable to meet because of the many limitations, especially resource constraints. The issues and difficulties associated with overcrowding in the emergency section were raised by respondents, who reported several challenges experienced in the hospital. These included patients sleeping on floor mattresses and even on stretchers, inadequate beds, shortage of staff, malfunctioning equipment and lack of sufficient infrastructure. These challenges resulted in long waiting periods for patients to be given open beds in the wards, bad attitudes from both patients and employees alike, poor communication among staff and patients and their families, and an unsafe environment for the staff and customers (patients). There is hence a need for the Gauteng Health Department together with the hospital management to review resources allocated to the Edenvale Regional Hospital and to increase awareness among the community about the operations of the level 2 hospitals such as this. / Public Administration / M. P. A.