A Bayesian latent class safety performance function for identifying motor vehicle crash blackspots

The current state of the practice in Blackspot Identification (BSI) utilizes safety performance functions based on total crash counts to identify transport system sites with potentially high crash risk. This paper postulates that total crash count variation over a transport network is a result of multiple distinct crash generating processes including geometric characteristics of the road, spatial features of the surrounding environment, and driver behaviour factors. However, these multiple sources are ignored in current modelling methodologies in both trying to explain or predict crash frequencies across sites. Instead, current practice employs models that imply that a single underlying crash generating process exists. The model mis-specification may lead to correlating crashes with the incorrect sources of contributing factors (e.g. concluding a crash is predominately caused by a geometric feature when it is a behavioural issue), which may ultimately lead to inefficient use of public funds and misidentification of true blackspots. This study aims to propose a latent class model consistent with a multiple crash process theory, and to investigate the influence this model has on correctly identifying crash blackspots. We first present the theoretical and corresponding methodological approach in which a Bayesian Latent Class (BLC) model is estimated assuming that crashes arise from two distinct risk generating processes including engineering and unobserved spatial factors. The Bayesian model is used to incorporate prior information about the contribution of each underlying process to the total crash count. The methodology is applied to the state-controlled roads in Queensland, Australia and the results are compared to an Empirical Bayesian Negative Binomial (EB-NB) model. A comparison of goodness of fit measures illustrates significantly improved performance of the proposed model compared to the NB model. The detection of blackspots was also improved when compared to the EB-NB model. In addition, modelling crashes as the result of two fundamentally separate underlying processes reveals more detailed information about unobserved crash causes.

Patient Safety - A Psychological Perspective

This comprehensive book takes a psychological perspective on patient safety. It is based on the most recent theoretical and empirical research evidence from psychology (including clinical, work, and organizational psychology) and adjacent social and behavioral sciences such as human factors. Factors that influence safety-related experiences, behaviors, and outcomes of patients and professionals working in clinical settings such as medical practices and hospitals are reviewed, structured, and critically evaluated. Consistent with the complexity of the topic, the author takes a multi-level approach to patient safety, which includes a review of individual, team, and organizational factors and outcomes. The book describes how these factors, by themselves and in combination, can facilitate or impede patient safety. Individual factors include safety-relevant knowledge, skills, abilities, and personality traits such as conscientiousness and emotional stability. Team factors include group communication, training, and leadership. Finally, organizational factors include the safety culture and climate. Throughout the book, different evidence-based intervention programs are described that can help practitioners promote patient safety and prevent accidents. The book is a valuable resource for both researchers and practitioners interested in understanding, maintaining, and improving patient safety in a variety of applied settings. It is based on the most up-to-date research evidence from psychology and neighboring disciplines, and it is written in a clear and non-technical language understandable for a wide audience.

Medication incident reporting in residential aged care facilities: Limitations and risks to residents' safety

Background Medication incident reporting (MIR) is a key safety critical care process in residential aged care facilities (RACFs). Retrospective studies of medication incident reports in aged care have identified the inability of existing MIR processes to generate information that can be used to enhance residents’ safety. However, there is little existing research that investigates the limitations of the existing information exchange process that underpins MIR, despite the considerable resources that RACFs’ devote to the MIR process. The aim of this study was to undertake an in-depth exploration of the information exchange process involved in MIR and identify factors that inhibit the collection of meaningful information in RACFs. Methods The study was undertaken in three RACFs (part of a large non-profit organisation) in NSW, Australia. A total of 23 semi-structured interviews and 62 hours of observation sessions were conducted between May to July 2011. The qualitative data was iteratively analysed using a grounded theory approach. Results The findings highlight significant gaps in the design of the MIR artefacts as well as information exchange issues in MIR process execution. Study results emphasized the need to: a) design MIR artefacts that facilitate identification of the root causes of medication incidents, b) integrate the MIR process within existing information systems to overcome key gaps in information exchange execution, and c) support exchange of information that can facilitate a multi-disciplinary approach to medication incident management in RACFs. Conclusions This study highlights the advantages of viewing MIR process holistically rather than as segregated tasks, as a means to identify gaps in information exchange that need to be addressed in practice to improve safety critical processes.

Using Big Data to manage safety-related risk in the upstream oil and gas industry: A research agenda

Despite considerable effort and a broad range of new approaches to safety management over the years, the upstream oil & gas industry has been frustrated by the sector’s stubbornly high rate of injuries and fatalities. This short communication points out, however, that the industry may be in a position to make considerable progress by applying “Big Data” analytical tools to the large volumes of safety-related data that have been collected by these organizations. Toward making this case, we examine existing safety-related information management practices in the upstream oil & gas industry, and specifically note that data in this sector often tends to be highly customized, difficult to analyze using conventional quantitative tools, and frequently ignored. We then contend that the application of new Big Data kinds of analytical techniques could potentially reveal patterns and trends that have been hidden or unknown thus far, and argue that these tools could help the upstream oil & gas sector to improve its injury and fatality statistics. Finally, we offer a research agenda toward accelerating the rate at which Big Data and new analytical capabilities could play a material role in helping the industry to improve its health and safety performance.

Queuing Models for Estimating Aircraft Fleet Availability

The availability of a small fleet of aircraft in a flying-base, repair-depot combination is modeled and studied. First, a deterministic flow model relates parameters of interest and represents the state-of-the art in the planning of such systems. Second, a cyclic queue model shows the effect of the principal uncertainties in operation and repair and shows the consequent decrease in the availability of aircraft at the flying-base. Several options such as increasing fleet size, investments in additional repair facilities, or building reliability and maintainability into the individual aircraft during its life-cycle are open for increasing the availability. A life-cycle cost criterion brings out some of these features. Numerical results confirm Rose's prediction that there exists a minimal cost combination of end products and repair-depot capability to achieve a prescribed operational availability.

Safety impacts of alcohol and other drugs in construction

Estimated 638,400 persons suffered a work-related injury or illness in 2009-2010 and 337 lost their lives as a result in 2009-2010. In 2013-2014, there were 186 fatalities with 29 (16%) occurring in construction. Very little is known about what proportion of accidents are directly attributable to the effects of AOD. Anecdotal evidence highlights issues of AOD and its association with safety risk on construction sites. Research Objective: • To scientifically evaluate the relationship between the use of AOD and the safety impacts within the Australian construction industry to engender a cultural change in the workforce • A nationally consistent and collaborative approach involving government, employers and employees, unions and other key industry stakeholders

Simulation and modelling tools for quantitative safety assessments of unmanned aircraft systems and operations

This paper presents two simple simulation and modelling tools designed to aid in the safety assessment required for unmanned aircraft operations within unsegregated airspace. First, a fast pair-wise encounter generator is derived to simulate the See and Avoid environment. The utility of the encounter generator is demonstrated through the development of a hybrid database and a statistical performance evaluation of an autonomous See and Avoid decision and control strategy. Second, an unmanned aircraft mission generator is derived to help visualise the impact of multiple persistent unmanned operations on existing air traffic. The utility of the mission generator is demonstrated through an example analysis of a mixed airspace environment using real traffic data in Australia. These simulation and modelling approaches constitute a useful and extensible set of analysis tools, that can be leveraged to help explore some of the more fundamental and challenging problems facing civilian unmanned aircraft system integration.

Lactobacillus bacteremia, with special focus on the safety of probiotic Lactobacillus rhamnosus GG

Lactobacilli are gram positive rods, which belong to normal oropharyngeal, gastrointestinal and urogenital flora. They are widely used in food industry and as food additives. Although their virulence is presumed to be very low, opportunistic bacteremic infections, especially in immunocompromised hosts, have been detected. In the present study, the possible effects of increasing probiotic use of Lactobacillus rhamnosus GG (LGG) on the occurrence of bacteremia due to lactobacilli was evaluated on population level. In Finland, 90 Lactobacillus bacteremia cases were reported to the National Infectious Disease Register maintained by National Public Health Institute, during 1995-2000. Their proportion of all bacteremia cases was on average 0.24%, corresponding to 0.3 cases/100 000 inhabitants annually. In the Helsinki University Central Hospital district the corresponding proportion of all bacteremia cases was observed during 1990-2000. Despite LGG intake increased six folded no increasing trend in the occurrence of lactobacilli bacteremia was seen. A total of 85 Lactobacillus sp. blood isolates collected from different human bacteremic cases were characterised and compared with the commercial probiotic LGG strain. In species characterisation 46 L. rhamnosus strains, 12 L. fermentum and L. casei strains each, three each of L. gasseri, L. salivarius and L. jensenii species, two L. curvatus, and one each of L. plantarum, L. sakei, L. zeae and L. reuteri species were detected. Nearly half of the L. rhamnosus findings turned out to be indistinguishable from the probiotic LGG strain. Common predisposing factors to Lactobacillus bacteremia were immunosuppression, prior prolonged hospitalisation and prior surgical interventions. Severe or fatal comorbidities were found in 82% of the patients. Mortality at one month was 26% and severe underlying diseases were a significant predictor of death (OR 15.8). Antimicrobial susceptibility of Lactobacillus strains was species dependent. The Lactobacillus isolates were generally susceptible to imipenem, piperacillin-tazobactam, clindamycin and erythromycin, whereas all other than L. gasseri and L. jensenii species were not at all susceptible to vancomycin. The susceptibility to cephalosporin varied greatly even within species why they might not be recommended for treatment of Lactobacillus infections. The effect and safety of probiotic LGG preparation in amelioration of gastric symptoms and diarrhea in HIV-infected patients was evaluated. No significant differences in gastrointestinal symptoms or diarrhoea in LGG treated patients compared to placebo could be found. LGG was well tolerated with no adverse effects including bacteremic outbreaks could be observed. The use of probiotic LGG can be regarded safe in this immunocompromised patient group.

Addressing the challenges of road safety in India: Are there lessons from Australia?

An invited panel presentation on "Road Safety: Challenges and Way outs" Overview - Road trauma trends in Australia - Key features of Australia’s approach to road safety - Role of university-based research centres in promoting road safety in Australia - UN Decade of Action for Road Safety

Pharmacokinetics, efficacy, and safety of pravastatin in children : Studies in children with heterozygous familial hypercholesterolemia and in pediatric cardiac transplant recipients

Background. Hyperlipidemia is a common concern in patients with heterozygous familial hypercholesterolemia (HeFH) and in cardiac transplant recipients. In both groups, an elevated serum LDL cholesterol level accelerates the development of atherosclerotic vascular disease and increases the rates of cardiovascular morbidity and mortality. The purpose of this study is to assess the pharmacokinetics, efficacy, and safety of cholesterol-lowering pravastatin in children with HeFH and in pediatric cardiac transplant recipients receiving immunosuppressive medication. Patients and Methods. The pharmacokinetics of pravastatin was studied in 20 HeFH children and in 19 pediatric cardiac transplant recipients receiving triple immunosuppression. The patients ingested a single 10-mg dose of pravastatin, and plasma pravastatin concentrations were measured up to 10/24 hours. The efficacy and safety of pravastatin (maximum dose 10 to 60 mg/day and 10 mg/day) up to one to two years were studied in 30 patients with HeFH and in 19 cardiac transplant recipients, respectively. In a subgroup of 16 HeFH children, serum non-cholesterol sterol ratios (102 x mmol/mol of cholesterol), surrogate estimates of cholesterol absorption (cholestanol, campesterol, sitosterol), and synthesis (desmosterol and lathosterol) were studied at study baseline (on plant stanol esters) and during combination with pravastatin and plant stanol esters. In the transplant recipients, the lipoprotein levels and their mass compositions were analyzed before and after one year of pravastatin use, and then compared to values measured from 21 healthy pediatric controls. The transplant recipients were grouped into patients with transplant coronary artery disease (TxCAD) and patients without TxCAD, based on annual angiography evaluations before pravastatin. Results. In the cardiac transplant recipients, the mean area under the plasma concentration-time curve of pravastatin [AUC(0-10)], 264.1 * 192.4 ng.h/mL, was nearly ten-fold higher than in the HeFH children (26.6 * 17.0 ng.h/mL). By 2, 4, 6, 12 and 24 months of treatment, the LDL cholesterol levels in the HeFH children had respectively decreased by 25%, 26%, 29%, 33%, and 32%. In the HeFH group, pravastatin treatment increased the markers of cholesterol absorption and decreased those of synthesis. High ratios of cholestanol to cholesterol were associated with the poor cholesterol-lowering efficacy of pravastatin. In cardiac transplant recipients, pravastatin 10 mg/day lowered the LDL cholesterol by approximately 19%. Compared with the patients without TxCAD, patients with TxCAD had significantly lower HDL cholesterol concentrations and higher apoB-100/apoA-I ratios at baseline (1.0 ± 0.3 mmol/L vs. 1.4 ± 0.3 mmol/L, P = 0.031; and 0.7 ± 0.2 vs. 0.5 ± 0.1, P = 0.034) and after one year of pravastatin use (1.0 ± 0.3 mmol/L vs. 1.4 ± 0.3 mmol/L, P = 0.013; and 0.6 ± 0.2 vs. 0.4 ± 0.1, P = 0.005). Compared with healthy controls, the transplant recipients exhibited elevated serum triglycerides at baseline (median 1.3 [range 0.6-3.2] mmol/L vs. 0.7 [0.3-2.4] mmol/L, P=0.0002), which negatively correlated with their HDL cholesterol concentration (r = -0.523, P = 0.022). Recipients also exhibited higher apoB-100/apoA1 ratios (0.6 ± 0.2 vs. 0.4 ± 0.1, P = 0.005). In addition, elevated triglyceride levels were still observed after one year of pravastatin use (1.3 [0.5-3.5] mmol/L vs. 0.7 [0.3-2.4] mmol/L, P = 0.0004). Clinically significant elevations in alanine aminotransferase, creatine kinase, or creatinine ocurred in neither group. Conclusions. Immunosuppressive medication considerably increased the plasma pravastatin concentrations. In both patient groups, pravastatin treatment was moderately effective, safe, and well tolerated. In the HeFH group, high baseline cholesterol absorption seemed to predispose patients to insufficient cholesterol-lowering efficacy of pravastatin. In the cardiac transplant recipients, low HDL cholesterol and a high apoB-100/apoA-I ratio were associated with development of TxCAD. Even though pravastatin in the transplant recipients effectively lowered serum total and LDL cholesterol concentrations, it failed to normalize their elevated triglyceride levels and, in some patients, to prevent the progression of TxCAD.

Promoting sun safety in the workplace – what works?

Objective Australia has one of the highest skin cancer incidence and mortality rates in the world. Outdoor workers are a high risk group. Australian workplaces are undergoing large scale safety related changes, yet the mandate to provide specific sun safe practices remains absent. With much of the previous research aiming to improve sun safety in the workplace being quantitative in nature, relatively little is known about why certain sun safe strategies will or will not be successful in workplaces. Methods This qualitative article explores the enablers and barriers identified during an 18-month mixed methods project conducted in Queensland, Australia which aimed to improve workplace sun safe interventions. Results A variety of key enablers and barriers to implementing sun safe interventions in the workplace were identified, including presence of an engaged workplace champion, ownership and innovation by the workers. Conclusions These findings were part of a broader integration of interlinked qualitative and quantitative methods to yield a more complete picture of the determinants of the issue, implementation process and likelihood of changes at the workplace. Implications The paper provides guidance for public and occupational health practitioners on the selection of the most promising strategies when assisting workplaces to become sun safe.

The skin safety model: Reconceptualizing skin vulnerability in older patients

Purpose: To develop a unique skin safety model (SSM) that offers a new and unified perspective on the diverse yet interconnected antecedents that contribute to a spectrum of potential iatrogenic skin injuries in older hospitalized adults. Organizing Construct: Discussion paper. Methods: A literature search of electronic databases was conducted for published articles written in English addressing skin integrity and iatrogenic skin injury in elderly hospital patients between 1960 and 2014. Findings: There is a multiplicity of literature outlining the etiology, prevention, and management of specific iatrogenic skin injuries. Complex and interrelated factors contribute to iatrogenic skin injury in the older adult, including multiple comorbidities, factors influencing healthcare delivery, and acute situational stressors. A range of injuries can result when these factors are com- plicated by skin irritants, pressure, shear, or friction; however, despite skin injuries sharing multiple ntecedents, no unified overarching skin safety conceptual model has been published. Conclusions: The SSM presented in this article offers a new, unified framework that encompasses the spectrum of antecedents to skin vulnerability as well as the spectrum of iatrogenic skin injuries that may be sustained by older acute care patients. Current skin integrity frameworks address prevention and management of specific skin injuries. In contrast, the SSM recognizes the complex interplay of patient and system factors that may result in a range of iatrogenic skin injuries. Skin safety is reconceptualized into a single model that has the potential for application at the individual patient level, as well as health-care systems and governance levels. Clinical Relevance: Skin safety is concerned with keeping skin safe from any iatrogenic skin injury, and remains an ongoing challenge for healthcare providers. A conceptual framework that encompasses all of the factors that may contribute to a range of iatrogenic skin injuries is essential, and guides the clinician in maintaining skin integrity in the vulnerable older patient.