Acute impairing effects of morphine related to driving: A systematic review of experimental studies to define blood morphine concentrations related to impairment in opioid-naïve subjects

Objective: The objective of this study was to look for dose– and concentration–effect relationships in experimental studies on single-dose administration of morphine on traffic-relevant behavioral tests by a systematic literature review and possibly to see whether a dose/concentration could be defined below which few or no tests would be affected.

Methods: Searches for corresponding literature were conducted using MEDLINE, EMBASE, and PsycINFO, throughout March of 2016. The search strategy consisted of words colligated to cognitive and psychomotor functions of relevance to driving, in relation to morphine administration. The tests were arranged in main groups, and tests showing impairment were categorized by doses as well as calculated plasma concentrations.

Results: Fifteen studies were included in the review. Impairment after the administration of a single intravenously dose of morphine was found in some of the tests on reaction time, attention, and visual functions. No impairment was observed in tests on psychomotor skills and en-/decoding. Tests on reaction time appeared to be less sensitive to the morphine administration, whereas tests on visual functions and attention appeared to be the most sensitive to the morphine administration. Single-dose administration of morphine with dosages up to 5 mg appeared to cause very few effects on traffic-relevant performance tasks. At higher dosages, impairment was found on various tasks but with no clear dose–effect relationship. Plasma morphine concentrations less than 50 nmol/L are most probably accompanied by few effects on traffic-relevant performance tasks.

Conclusions: A plasma morphine concentration of 50 nmol/L (approximately 14.3 ng/mL) could represent an upper level, under which there is little accompanying road traffic risk. A single dose of 5 mg morphine IV and analgetic equivalence doses of fentanyl, hydromorphone, oxycodone, and oxymorphone are presented with the suggestion that few traffic-relevant effects will appear after such doses.     

When may road fatalities start to decrease?

Introduction

The comparative analysis of macroscopic trends in road safety has been a popular research topic. The objective of this research is to propose a simple and, at the same time, reliable multiple regime model framework for international road safety comparisons, allowing for the identification of slope changes of personal risk curves and respective breakpoints.

Method

The trends of road traffic fatalities in several EU countries have been examined through the temporal evolution of elementary socioeconomic indicators, namely motorized vehicle fleet and population, at the country level.

Results

Piece-wise linear regression models have been fitted, using a methodology that allows the simultaneous estimation of all slopes and breakpoints. The number and location of breakpoints, as well as the slope of the connecting trends, vary among countries, thus indicating different road safety evolution patterns.

Impact on industry

Macroscopic analysis of road accident trends may be proved beneficial for the identification of best examples and the implementation of appropriate programmes and measures, which will lead to important benefits for the society and the economy through the reduction of road fatalities and injuries. Best performing countries and the related programmes and measures adopted may concern several safety improvements at the processes of the road, the vehicle and the insurance industries.

Conclusions

Lessons from the analysis of the past road safety patterns of developed countries provide some insight into the underlying process that relates motorization levels with personal risk and can prove to be beneficial for predicting the road safety evolution of developing countries that may have not yet reached the same breakpoints. Furthermore, the presented framework may serve as a basis to build more elaborate models, including more reliable exposure indicators (such as vehicle-km driven).     

Are pilots at risk of accidents due to fatigue?

PROBLEM: There is concern in the aviation community that pilot schedules can lead to fatigue and increased chance of an aviation accident. Yet despite this concern, there is little empirical analysis showing the relationship between pilot schedules and commercial aviation accidents. This study attempts to demonstrate an empirical relationship between pilot schedules and aviation accidents. METHOD: Data for human factors-related accidents and pilot work patterns were identified. The distribution of pilot work schedule parameters for the accidents was compared to that for all pilots using a chi-square test to determine if the proportions of accidents and length of duty exposure were the same. If the distributions are the same, then one could infer that pilot human factor accidents are not affected by work schedule parameters. RESULTS: The proportion of accidents associated with pilots having longer duty periods is higher than the proportion of longer duty periods for all pilots. DISCUSSION: There is a discernible pattern of increased probability of an accident as duty time increases for commercial aircraft pilots in the United States. IMPACT ON INDUSTRY: The analysis suggests that establishing limits on duty time for commercial pilots would reduce risk. Such a rule is likely to be expensive and could substantially impact the commercial airlines. In return, there is likely to be a reduction in the risk of commercial aviation accidents due to pilot fatigue.     

The unequal distribution of occupational health and safety risks among immigrants to Canada compared to Canadian-born labour market participants: 1993–2005

ObjectivesTo examine the prevalence of occupational health and safety risk factors among immigrants to Canada compared to Canadian-born labour force participants.MethodsUsing data from Statistic Canada’s Survey of Labour and Income Dynamics, we examined the differential probabilities of six different occupational health and safety risks: non-membership in a union or collective bargaining agreement; employment in physically demanding occupations; employment in a workplace with less than 20 employees; regular shift work; irregular shift work; and having non-permanent employment. Our main independent variables were length of time in Canada, visible minority status, mother tongue, and location where highest level of education was attained. Models were adjusted for age, gender, education, marital status, province of residence, living in an urban or rural location, and industry group.ResultsOf the six occupational health and safety risks examined we found that our main independent variables describing aspects of immigration status were associated with five; the exception being irregular shift work. Adjustment for industry did not attenuate these relationships to a large extent.ConclusionsImmigrants to Canada are faced with many occupational health and safety risks compared to Canadian-born respondents. These risks may be heightened among immigrants as they may not have knowledge of workplace rights and protections or have problems communicating health and safety risks or concerns. The timely provision information on occupational health and safety to immigrants before they start working should be a priority as they integrate into the Canadian labour market.     

Is career management related to employee development and performance?

The career management process involves career exploration, development of career goals, and use of career strategies to obtain career goals. The relationship between different aspects of the career management process and employee development behavior and performance was examined in this study. Employees provided information concerning their personal characteristics, career management strategies, their manager's support for career development, and willingness to participate in development activities. Managers provided ratings of each employee's job performance and developmental behavior. Position, manager's support for development, environmental exploration, and distance from career goal explained significant variance in employees' willingness to participate in development activities and developmental behavior. Career management was not significantly related to performance ratings. Research and practical implications of the study findings are discussed.     

When does adaptive performance lead to higher task performance?

Adaptive performance is a facet of performance that reflects acquiring enhanced competencies in response to change. Micro‐level researchers have assumed that adaptive performance is beneficial for task performance. Similarly, macro‐level researchers have suggested that organizations need to attend to, monitor, and respond to contingencies in their environments for adaptive performance to be beneficial for firm performance. Drawing from the attention‐based theory of the firm and resource theory, we suggest that perceptions of organizational politics and individual differences in conscientiousness constitute contingencies of the adaptive performance–task performance relationship. In a sample of 92 call center employees, we found that adaptive performance is positively associated with task performance but that conscientiousness and organizational politics jointly influence the adaptive performance–task performance relationship. Copyright © 2011 John Wiley & Sons, Ltd.     

A safety counterculture challenge to a “safety climate”

This case study is about a small group of workmen caught in a common dilemma regarding work safety. They must work safely and maintain production within a pathological organization that does not meaningfully reward participation or communication. They do so as a group and socially construct danger, injury and safety for themselves. They constitute a functioning counterculture and challenge the safety climate contrived by managers. Although limited in scope, the study suggests that we can learn from the details of their interactions with their work environment, with one another, and with their managers.     

How do organizational practices relate to perceived system safety effectiveness? Perceptions of safety climate and co-worker commitment to safety as workplace safety signals

Introduction: Integrating safety climate research with signaling theory, we propose that individual perceptions of safety climate signal the importance of safety in the organization. Specifically, we expect that three work-related organizational practices (training effectiveness, procedure effectiveness, and work pressure) relate to the broader risk control system in the workplace via individual perceptions of safety climate as a broad management signal. Further, we expect this broad management signal interacts with a local environmental signal (co-worker commitment to safety) to amplify or diminish perceived system safety effectiveness. Method: In a field study of oil and gas workers (N = 219; Study 1), we used mediation modeling to determine the relationships between work-related organizational practices, perceived safety climate, and perceived safety system effectiveness. In a field study of railway construction workers (N = 131; Study 2), we used moderated mediation modeling to explore the conditional role of co-worker commitment to safety. Results: We found that training effectiveness, procedure effectiveness, and work pressure predicted perceived system safety effectiveness indirectly via perceived safety climate (Studies 1 and 2) and that these indirect paths are influenced by co-worker commitment to safety (Study 2). Conclusions: Findings suggest that perceived safety climate is driven in part by work practices, and that perceived safety climate (from managers) and co-worker commitment to safety (from the local environment) interact to shape workplace safety system effectiveness. Practical applications: The insight that training, procedures, and work pressure are meaningful predictors of perceived safety climate as a signal suggests that organizations should be cognizant of the quality of work-related practices for safety. The insight we offer on the competing versus complimentary nature of managerial safety signals (perceived safety climate) and co-worker safety signals (co-worker commitment to safety) could also be used by safety personnel to develop safety interventions directed in both areas.     

Got milk? Workplace factors related to breastfeeding among working mothers

The American Academy of Pediatrics recommends that women breastfeed because of improved health outcomes for mothers and children. Because maternal employment during the first year of the child's life has been identified as a reason for breastfeeding cessation, we develop and test a role‐theory‐based framework to explain women's continuation of breastfeeding after return to work (Study 1) and report results of an exploratory study linking breastfeeding at work with job attitudes and well‐being (Study 2). Applying survival analysis to a longitudinal dataset gathered by the Centers for Disease Control (Study 1), we identify pregnant women's perceived employer support for breastfeeding as a predictor of women's breastfeeding goal intentions. Supervisors' negative workplace remarks about breastfeeding related to an eightfold increase of women's likelihood to discontinue exclusive breastfeeding and perceived support for breastfeeding after return to work predicted exclusive breastfeeding continuation. Results of Study 2 suggest that women who return to work and continue breastfeeding experience more family‐to‐work conflict and overload than women who do not reconcile work and breastfeeding. Further, results of Study 2 provide preliminary evidence suggesting that perceptions of supervisor and coworker support for breastfeeding relate positively to general perceptions of organizational support and negatively to depressive symptoms. Copyright © 2015 John Wiley & Sons, Ltd.     

Skin reactions to latex in dental professionals – first Croatian data

Purpose. To determine the prevalence of undesirable skin reactions to latex in dental professionals and students of the School of Dental Medicine in Zagreb, Croatia. Methods. Our research included 444 participants, of which 200 agreed to undergo a skin prick test (SPT). All participants answered a questionnaire in which we asked about incidence of skin lesions, duration of occupational exposure to latex, localization of skin lesions and symptoms. Statistical analysis of the questionnaire and test results was then carried out. Results. Of the total 444 participants surveyed, 249 (56.1%) reported lesions on their skin (professionals 64.8%, students 6.1–58.5%). From the questionnaire, 239 (96.0%) respondents reported lesions on the hands and fingers, mostly in the form of erythema (37.0%) and occasional dryness of skin (29.0%). Positive SPT results were found in 14 (7.0%) out of the 200 respondents who underwent the test. Conclusions. While a large number of subjects (56.1%) reported skin lesions when using latex products at their workplace, the SPT test was positive only in 7.0%. The results show that the prevalence of self-reported skin lesions was significantly related to the length of occupational exposure, with a substantial effect size (p?<?0.001; V?=?0.334).     

Analyzing motorists’ responses to temporary signage in highway work zones

For decades, the importance of highway work zone safety has increased considerably with the continual increase in the number of highway work zones present on highways for repairs and expansion. Rural work zones on two-lane highways are particularly hazardous and cause a significant safety concern due to the disruption of regular traffic flow. In this study, researchers determined motorists’ responses to warning signs in rural, two-lane highway work zones. The researchers divided vehicles into three classes (passenger car, truck, and semitrailer) and compared the mean change in speed of these classes based on three different sign setups: portable changeable message sign (PCMS) OFF, PCMS ON with the message of Slow Down, Drive Safely, and a temporary traffic sign (W20-1, “Road Work Ahead”). Field experiments were conducted on two two-lane work zones with flagger control. Statistical analyses were performed to determine whether there was a significant interaction between motorists’ responses and the sign setups. Data analysis results show that a visible PCMS, either turned on or off, was most effective in reducing truck speeds in rural, two-lane work zones. The temporary traffic sign (W20-1) was more effective in reducing the vehicle speeds of passenger car and semitrailer. Results of this research project will help traffic engineers to better design the two-lane work zone setup and take necessary safety countermeasures to prevent vehicle crashes.     

Car drivers with dementia: Different complications due to different etiologies?

Objective: Older drivers with dementia are an at-risk group for unsafe driving. However, dementia refers to various etiologies and the question is whether dementias of different etiology have similar effects on driving ability.

Methods: The literature on the effects of dementia of various etiologies on driving ability is reviewed. Studies addressing dementia etiologies and driving were identified through PubMed, PsychINFO, and Google Scholar.

Results and Conclusions: Early symptoms and prognoses differ between dementias of different etiology. Therefore, different etiologies may represent different likelihoods with regard to fitness to drive. Moreover, dementia etiologies could indicate the type of driving problems that can be expected to occur. However, there is a great lack of data and knowledge about the effects of almost all etiologies of dementia on driving. One could hypothesize that patients with Alzheimer's disease may well suffer from strategic difficulties such as finding a route, whereas patients with frontotemporal dementia are more inclined to make tactical-level errors because of impaired hazard perception. Patients with other dementia etiologies involving motor symptoms may suffer from problems on the operational level. Still, the effects of various etiologies of dementias on driving have thus far not been studied thoroughly. For the detection of driving difficulties in patients with dementia, structured interviews with patients but also their family members appear crucial. Neuropsychological assessment could support the identification of cognitive impairments. The impact of such impairments on driving could also be investigated in a driving simulator. In a driving simulator, strengths and weaknesses in driving behavior can be observed. With this knowledge, patients can be advised appropriately about their fitness to drive and options for support in driving (e.g., compensation techniques, car adaptations). However, as long as no valid, reliable, and widely accepted test battery is available for the assessment of fitness to drive, costly on-road test rides are inevitable. The development of a fitness-to-drive test battery for patients with dementia could provide an alternative for these on-road test rides, on condition that differences between dementia etiologies are taken into consideration.     

“Hypersensitivity to Electricity” in the Office; Symptoms and Improvement

Nineteen persons “hypersensitive” to electricity and 20 nonafflicted persons were studied for 1 ½ years. The most discernible hypersensitivity symptoms were pricking sensations and redness in the face, but these symptoms were present in only half of the afflicted. Other symptoms were similar to symptoms experienced during office work and this study does not support the idea that electrosensitivity is one single syndrome. The “hypersensitive” persons improved significantly, mainly on neuropsychiatric symptoms, but the skin problems sustained— as did the belief about their cause. The afflicted persons used less conventional medication than the group of the nonafflicted, which suggests a general tendency for attribution to environmental factors.     

A Contribution to the Study of the Antidust Respirators’ Real Performance

In most industrial enterprises, hazardous factors are present in quantities exceeding permissible levels. Such a situation requires using antidust respiratory protection. It has been suggested, however, that filters for respirators are not assessed properly and that lab results might not be related to real filtering efficiency in industry. This article contains test results of some commercially available filtering half-masks, including the effect of loading with real dust, high humidity, high temperature, and a combination of loading with dust and high humidity on the half-masks’ performance. The results show that the effect of these factors is considerable and that a combination of loading with silica dust and exposing to high humidity can cause a complete loss of performance.     

The National Falls Free™ Initiative, working collaboratively to affect change

Introduction

Since 2004 the National Council on Aging (NCOA) has been working in collaboration with a growing number of national, state, and local organizations through the Falls Free^© Initiative to address the growing public health issue of falls and fall-related injuries among older adults. Through collaborative leadership, evidence-based interventions, practical lifestyle adjustments, and community partnerships we are working to reduce the number of older adult falls.

Impact on industry

The many activities of the national and state coalitions have brought recognition to the issue of fall prevention, education, and training to providers and greater investment in programs and services resulting in tremendous momentum and community activism. While we have yet to realize an impact on rates of falls, this strategic investment in building the infrastructure needed to affect change is the first step toward reducing the growing number of falls among older adults.     

What motivates employers to establish preventive management arrangements within supply chains?

This paper examines existing evidence as to the factors that prompt organisations to utilise supply chains to influence how health and safety is managed within them, with a view to shedding light on how far it serves to confirm or challenge the view that in general employers are unlikely to voluntarily pursue preventive management initiatives in the absence of external regulatory pressures. The analysis reveals a range of initiatives undertaken to utilise supply chains to support improvements in health and safety management, both at the level of individual organisations and via trade and industry bodies. It also, however, indicates that while supply chains can be used to improve how health and safety is managed within them, only in relatively narrowly defined circumstances will market-based business motivations alone serve to encourage the utilisation of this potential. It is further concluded that if policy-makers wish to see supply chains used more widely to improve standards of health and safety standards, then they need to do more than merely encourage voluntary action in this regard.     

Using Sound to Reduce Visual Distraction from In-vehicle Human–Machine Interfaces

Objective: Driver distraction and inattention are the main causes of accidents. The fact that devices such as navigation displays and media players are part of the distraction problem has led to the formulation of guidelines advocating various means for minimizing the visual distraction from such interfaces. However, although design guidelines and recommendations are followed, certain interface interactions, such as menu browsing, still require off-road visual attention that increases crash risk. In this article, we investigate whether adding sound to an in-vehicle user interface can provide the support necessary to create a significant reduction in glances toward a visual display when browsing menus.

Methods: Two sound concepts were developed and studied; spearcons (time-compressed speech sounds) and earcons (musical sounds). A simulator study was conducted in which 14 participants between the ages of 36 and 59 took part. Participants performed 6 different interface tasks while driving along a highway route. A 3 × 6 within-group factorial design was employed with sound (no sound /earcons/spearcons) and task (6 different task types) as factors. Eye glances and corresponding measures were recorded using a head-mounted eye tracker. Participants’ self-assessed driving performance was also collected after each task with a 10-point scale ranging from 1 = very bad to 10 = very good. Separate analyses of variance (ANOVAs) were conducted for different eye glance measures and self-rated driving performance.

Results: It was found that the added spearcon sounds significantly reduced total glance time as well as number of glances while retaining task time as compared to the baseline (= no sound) condition (total glance time M = 4.15 for spearcons vs. M = 7.56 for baseline, p =.03). The earcon sounds did not result in such distraction-reducing effects. Furthermore, participants ratings of their driving performance were statistically significantly higher in the spearcon conditions compared to the baseline and earcon conditions (M = 7.08 vs. M = 6.05 and M = 5.99 respectively, p =.035 and p =.002).

Conclusions: The spearcon sounds seem to efficiently reduce visual distraction, whereas the earcon sounds did not reduce distraction measures or increase subjective driving performance. An aspect that must be further investigated is how well spearcons and other types of auditory displays are accepted by drivers in general and how they work in real traffic.     

Learning from accidents – What more do we need to know?

A model of experience feedback (the CHAIN model) that emphasizes the whole chain from initial reporting to preventive measures is used to identify important research needs in the field of learning from accidents. Based on the model, six quality criteria for experience feedback after an accident or incident are presented. Research on experience feedback from accidents is reviewed. The overall conclusion is that the discipline of experience feedback has not been sufficiently self-reflective. The process of experience feedback can and should be applied to experience feedback itself, but that is rarely done. Evaluation studies are needed that provide hard (evidence-based) information about the effects of various methodologies and organizational structures. Four types of studies are particularly important for the development of evidence-based accident investigation practices: (1) studies of the effects and the efficiency of different accident investigation methods, (2) studies of the dissemination of conclusions from accident investigation, (3) follow-up studies of the extent to which accident investigation reports give rise to actual preventive measures, and (4) studies of the integration of experience feedback systems into overall systems of risk management.