Cognitive Interview Validation of a Novel Household Hazard Vulnerability Assessment Instrument

BACKGROUND

Weather and climate disasters are responsible for over 13 000 US deaths, worsened morbidity, and $1.7 trillion in additional costs over the last 40 years with profound racial disparities.

OBJECTIVES

This project empirically generated items for a novel survey instrument of household hazard vulnerability with initial construct validation while addressing racial bias in the data collection process.

METHODS

Cognitive interviews facilitated understanding regarding the performance of drafted survey questions with transdisciplinary expert panelists from diverse US regions on unique hazard/disaster/event items. To prevent representation bias in data collection, those with Black and/or African American racial, biracial, or multiracial identities were over-sampled. Interview video recordings were qualitatively analyzed using thematic and pattern coding.

RESULTS

A cognitive process mapped to themes of disaster characteristics, resources, individual life facets, and felt effects was revealed. We identified 379 unique instances of linked terms as synonyms, co-occurring, compounding, or cascading events. Potential for racial bias in data collection was elucidated. Analysis of radiation exposure, trauma, and criminal acts of intent items revealed participants may not interpret survey items with these terms as intended.

CONCLUSION

Potential for racial bias exists relative to water dam failure, evacuation, external flood, suspicious packages/substances, and transportation failure. Hazard terms that were not interpreted as intended require further revision in the validation process of individual or household disaster vulnerability assessments. Several commonalities in the cognitive process and mapping of disaster terms may be utilized in disaster and climate change research aimed at the individual and household unit of analysis.

Effect of peeling, cutting, or shredding of lettuce, carrot, or potato on the efficacy of chlorine disinfection

Minimally processed vegetables are washed and subsequently disinfected by immersion in water solutions with antimicrobials which reduce the initial pathogenic or spoilage microbial load. Chlorine remains one of the most widely used disinfectants for vegetables and hence the importance of studying its properties. The aim of this study was to evaluate the effect of peeling, cutting, and shredding on the effectiveness of chlorine (200 ppm) as a disinfectant in lettuce, carrot, and potato. Three independent repetitions of each experiment were completed, and data was statistically analyzed. Results showed that the maintenance of the chlorine concentration in the disinfectant solution, over time, depended on the vegetables' preliminary processing technique (whole, peeled, cut, or shredded) (p < 0.05). In general, the disinfection treatments studied reduced Escherichia coli by 1-8 logs. The addition of chlorine in the disinfectant solution allowed greater reduction in E. coli than using water immersions (p < 0.05) and disinfection times longer than 5 min did not improve these microbiological reductions (p>0.05). The vegetables' subdivision (whole, peeled, cut, or shredded) can affect both E coli's reduction and the vegetables' residual chlorine concentration. No trend was observed in terms of sensory differences and their relationship to the vegetables' processing and disinfection. These results suggest that each facility must validate its disinfection processes, according to the conditions established on site and reduction goals related to initial microbial counts, vegetables' quality, processing operations, and other important aspects.

Analysis and health risk assessments of heavy metals and nitrate migration into pickle beverages

This research aimed to investigate the levels of heavy metals (lead, cadmium, inorganic arsenic, and aluminium) and nitrate contaminants in pickle beverages sold in the Turkey market produced from various fruits and vegetables. In addition, carcinogenic and noncarcinogenic risk assessments of exposure resulting from oral consumption of these beverages have also been made. The heavy metal concentrations in 22 pickle beverages were found to be in the range of 0.369 to 119.181 for Al, 0.136 to 6.561 for iAs, 0.020 to 1.326 for Cd, and 0.118 to 3.632 µg/L for Pb, while the nitrate concentrations were <  limits of detection (LOD) 117.320 mg/L. Hazard quotient values for heavy metals and nitrate are calculated as <1 in both genders and are safe regarding noncarcinogenic risks. Lifetime carcinogenic risk assessment indicated that some pickle beverages might pose a carcinogenic risk at grade A (>10^-4) for iAs and grade B (10^-6-10^-4) for Pb in both genders.

Decline in Traffic Congestion Increased Crash Severity in the Wake of COVID-19

Highway fatalities are a leading cause of death in the U.S. and other industrialized countries. Using highly detailed crash, speed, and flow data, we show highway travel and motor vehicle crashes fell substantially in California during the response to the COVID-19 pandemic. However, we also show the frequency of severe crashes increased owing to lower traffic congestion and higher highway speeds. This "speed effect" is largest in counties with high pre-existing levels of congestion, and we show it partially or completely offsets the "VMT effect" of reduced vehicle miles traveled on total fatalities. During the first eleven weeks of the COVID-19 response, highway driving decreased by approximately 22% and total crashes decreased by 49%. While average speeds increased by a modest 2 to 3 mph across the state, they increased between 10 and 15 mph in several counties. The proportion of severe crashes increased nearly 5 percentage points, or 25%. While fatalities decreased initially following restrictions, increased speeds mitigated the effect of lower vehicle miles traveled on fatalities, yielding little to no reduction in fatalities later in the COVID period.

Efficacy and hazards of 425 nm oral cavity light dosing to inactivate SARS-CoV-2

Objective

Using a battery of preclinical tests to support development of a light-based treatment for COVID-19, establish a range of 425 nm light doses that are non-hazardous to the tissues of the oral cavity and assess whether a 425 nm light dose in this non-hazardous range can inactivate SARS-CoV-2 in artificial saliva.

Methods

The potential hazards to oral tissues associated with a range of acute 425 nm light doses were assessed using a battery of four preclinical tests: (1) cytotoxicity, using well-differentiated human large airway and buccal epithelial models; (2) toxicity to commensal oral bacteria, using a panel of model organisms; (3) light-induced histopathological changes, using ex vivo porcine esophageal tissue, and (4) thermal damage, by dosing the oropharynx of intact porcine head specimens. Then, 425 nm light doses established as non-hazardous using these tests were evaluated for their potential to inactivate SARS-CoV-2 in artificial saliva.

Results

A dose range was established at which 425 nm light is not cytotoxic in well-differentiated human large airway or buccal epithelial models, is not cytotoxic to a panel of commensal oral bacteria, does not induce histopathological damage in ex vivo porcine esophageal tissue, and does not induce thermal damage to the oropharynx of intact porcine head specimens. Using these tests, no hazards were observed for 425 nm light doses less than 63 J/cm² delivered at irradiance less than 200 mW/cm². A non-hazardous 425 nm light dose in this range (30 J/cm² at 50 mW/cm²) was shown to inactivate SARS-CoV-2 in vitro in artificial saliva.

Conclusion

Preclinical hazard assessments and SARS-CoV-2 inactivation efficacy testing were combined to guide the development of a 425 nm light-based treatment for COVID-19.

Clinical significance

The process used here to evaluate the potential hazards associated with 425 nm acute light dosing of the oral cavity to treat COVID-19 can be extended to other wavelengths, anatomical targets, and therapeutic applications to accelerate the development of novel photomedicine treatments.

Hazards for the Implementation and Use of Artificial Intelligence Enabled Digital Health Interventions, a UK Perspective

BACKGROUND

Artificial Intelligence (AI) has seen an increased application within digital healthcare interventions (DHIs). DHIs use entails challenges about their safety assurance. Exacerbated by regulatory requirements, in the UK, this places the onus of safety assurance not only on the manufacturer, but also on the operator of a DHI. Clinical Safety claims and evidencing safe implementation and use of AI-based DHIs require expertise, to understand and act to control or mitigate risk. Current health software standards, regulation, and guidance do not provide the insight necessary for safer implementation.

OBJECTIVE

To interpret published guidance and policy related to AI and justify clinical safety assurance of DHIs.

METHOD

Assessment of UK health regulation policy, standards, and AI institution insights, utilizing a published Hazard Assessment framework, to structure safety justifications, and articulate hazards relating to AI-based DHIs.

RESULTS

AI enabled DHI hazard identification, relating to implementation and use within healthcare delivery organizations.

CONCLUSION

By application of the method, we postulate that UK research of AI DHIs highlighted issues that may affect safety, in need of consideration to justify safety of a DHI.

Trend of lung cancer surgery, hospital selection, and survival between 2005 and 2016 in South Korea

Background

Studies on the clinical implication of hospital selection for patients with lung cancer are few. Therefore, this study aimed to analyze 2005–2016 data from the Korean national database to assess annual trends of lung cancer surgery and clinical outcomes according to hospital selection.

Methods

Data of 212 554 patients with lung cancer who underwent upfront surgery were screened. Trends according to sex, age, residence, and income were examined. Descriptive statistics were performed, and p_trend values were estimated. The association between survival and hospital selection was assessed using the log‐rank test. A multivariate Cox regression analysis was also performed.

Results

A total of 49 021 patients were included in this study. Surgery was prevalent among men, patients aged 61–75 years, capital area residents, and high‐income patients. However, with the increasing rate of surgery among women, patients aged ≥76 years, city residents, and middle‐income patients, the current distribution of lung cancer surgery could change. The rate of lobectomy among these groups increased. All patients, except those in capital areas, preferred a hospital outside their area of residence (HOR); the number of patients with this tendency also increased. However, this trend was not observed among low‐income patients and those aged ≥76 years. There were significant differences in survival according to hospital selection.

Conclusions

The trend of lung cancer surgery is changing. The current medical system is effective in providing lobectomy for patients including women, aged ≥76 years, city residents, and middle‐income. Increasing tendency to choose an HOR requires further study.

Beyond the Hazard Vulnerability Analysis: Preparing Health Systems for Climate Change

INTRODUCTION

Climate change is heightening both long-term adverse risks to human health and the immediate-term risk of injuries and illness following climate-related disaster events that are becoming more frequent and severe. In addition to its direct health effects, climate change poses new threats to the nation's health care infrastructure - with potential to negatively impact healthcare capacity amidst increasing demand - through risks of flooding, wind damage, heat stress, power outages, and other physical harm to facilities. The typical Hazard Vulnerability Analyses conducted annually by hospitals use historical data to assess risks; these analyses are likely now inadequate for future preparation due to the impact of climate change. This article describes one approach to how healthcare leaders can better assess both near-term and long-term risks due to climate change, to mitigate against unprecedented but foreseeable threats.

METHODS

In our large health system in the US Northeast, a process was undertaken to gather updated data and expert projections to forecast threats faced by each of our facilities in different climate-related disaster scenarios. Hazards examined in our setting included precipitation-based and coastal flooding events, heat waves, and high wind events, in addition to seismic events. Probabilities of occurrence and extents of different hazards were projected for the near term (2030) and the long term (2070). We then performed detailed vulnerability analyses for each facility with the predicted amount of rainfall, storm surge, heat stress, and windspeed, in collaboration with leaders at each facility. This was followed by a process to understand what would be needed to mitigate each vulnerability along with the associated costs. Ultimately, a cost/benefit analysis was performed - incorporating the relative likelihood and impact of different scenarios - to decide which improvement projects to embark on immediately, and what to defer and/or incorporate into future building plans.

RESULTS

In our system, all facilities were vulnerable to the effects of increased temperatures, and multiple hospitals were noted to be vulnerable to extreme precipitation, storm surge, and high winds. Specific damaging scenarios identified included flooding of basements and building infrastructure spaces, water entry through windows during high winds, and overheating of power systems during heat waves. Potential solutions included improved power redundancy for cooling systems, enhancements to roof and window systems, and the acquisition of deployable flood barriers. We identified four categories for prioritization of action based on projected impact: 1) priorities in need of urgent mitigation, 2) priorities in need of investigative study for medium-term mitigation, 3) priorities for planned capital improvement projects, and 4) priorities to integrate into new facility construction.

DISCUSSION

While the specific risks and vulnerabilities for each facility will differ according to its location and structural features, the approach we describe is broadly applicable. By forecasting specific risks, diagnosing vulnerabilities, developing potential solutions, and using a risk/benefit approach to decision making, hospitals can work toward protecting facilities and patients in the face of potential climate related natural disasters in an economically sound manner.

Association of atrial septal fenestration with outcomes after atrioventricular septal defect repair

OBJECTIVE

During repair of atrioventricular septal defect (AVSD), surgeons might leave an atrial level shunt when concerned about postoperative physiology, or as part of routine practice. However, the association of fenestration with outcomes is unclear. We sought to determine factors associated with mortality after biventricular repair of AVSD.

METHODS

We included 581 patients enrolled from 32 Congenital Heart Surgeons' Society institutions from January 1, 2012, to June 1, 2020 in the Congenital Heart Surgeons' Society AVSD cohort. Parametric multiphase hazard analysis was used to identify factors associated with mortality. A random effect model was used to account for possible intersite variability in mortality.

RESULTS

An atrial fenestration was placed during repair in 133/581 (23%) patients. Overall 5-year survival after repair was 91%. Patients who had fenestration had an 83% 5-year survival versus 93% for those not fenestrated (P < .001). Variables associated with mortality in multivariable hazard analysis included institutional diagnosis of ventricular unbalance (hazard ratio [HR], 2.7 [95% confidence interval (CI): 1.5-4.9]; P = .003), preoperative mechanical ventilation (HR, 4.1 [95% CI, 1.3-13.1]; P = .02), atrial fenestration (HR, 2.8 [95% CI, 1.5-4.9]; P < .001), and reoperation for ventricular septal defect (HR, 4.0 [95% CI, 1.3-13.1]; P = .002). There was no difference in measures of ventricular unbalance for comparisons of fenestrated with nonfenestrated patients. No significant interinstitution variability in mortality was observed on the basis of the random effect model (P = .7).

CONCLUSIONS

An atrial communication at biventricular repair of AVSD is associated with significantly reduced long-term survival after adjusting for other known associated factors, including unbalance. These findings might challenge the routine practice of fenestration.

Investigation of Potential Reservoirs of Non-Tuberculous Mycobacteria in a European Sea Bass (Dicentrarchus labrax) Farm

Fish mycobacteriosis is a widespread global problem caused by species of non-tuberculous mycobacteria (NTM). Mycobacterium marinum is one of the species most often involved in disease episodes of aquarium and farmed fish. Since there is currently no available effective therapy or vaccine, a prompt search for routes of entry is key to limiting the damage induced by the disease. Here we report a case of mycobacteriosis follow up in a European sea bass (Dicentrarchus labrax) farm located in Northern Italy, in which environmental samples and newly added fish batches were analyzed. Samples from fish present on the farm, sediment, and periphyton all resulted positive for M. marinum, whereas the new fish batches and the water samples resulted negative. The environmental resistance of NTM (alcohol-acid resistance, biofilm formation) and the lack of prophylactic and therapeutic strategies make these diseases difficult to manage. Prompt identification of biotic and abiotic reservoirs, combined with good zootechnical hygiene practices, are the most effective measures to control fish mycobacteriosis in intensive farms.

Stage-dependent conditional survival and failure hazard of non-metastatic nasopharyngeal carcinoma after intensity-modulated radiation therapy: Clinical implications for treatment strategies and surveillance

Purpose

Conditional survival (CS) and failure hazard estimations can provide important dynamic prognostic information for clinical decision‐making and surveillance counseling. The current study aimed to investigate the CS and dynamic failure hazard in non‐metastatic nasopharyngeal carcinoma (NPC) treated with intensity‐modulated radiotherapy (IMRT).

Methods

Conditional overall survival (COS) and progression‐free survival (CPFS) estimates adjusted for age and gender against each AJCC 8th stage were calculated. Multivariable Cox regression (MCR) models were fitted in the entire population at baseline and subsequently separate MCR models were fitted in patients who have maintained event‐free time of 1 to 10 years to generate respective hazard ratio (HR). Annual hazard rates of death and progression over 10 years for each stage were also estimated.

Results

A total of 1993 patients were eligible for analysis. The estimated 5‐year OS and PFS for entire cohort were 79.0% and 70.7% at initial diagnosis. After 5 years of event‐free follow‐up, additional 5‐year COS and CPFS increased to 85.9% and 85.5%, respectively. Stage I/II maintained dramatically favorable CS and low hazard (< 5%) of death and progression over time. Relative to stage I/II, stage III manifested non‐significantly higher failure hazard for the first 3 years of survivorship and approached to similar level of stage I/II afterwards. Stage IVA presented most impressive improvement in terms of both COS (∆=9.8%) and CPFS (∆ = 16.8%) whereas still drastically inferior to that of stage I‐III across all conditional time points. After 4 years of follow‐up, progression hazard of stage IVA became relatively steady of approximate 6%.

Conclusions

Survival prospect of non‐metastatic NPC improves over years with distinct dynamic patterns across stages, providing important implications for personalized decision‐making in terms of both clinical management and surveillance counseling. Stage‐dependent and hazard‐adapted clinical management and surveillance are warranted.

Implementation of food safety management systems that meets ISO 22000:2018 and HACCP: A case study of capsule biotechnology products of chaga mushroom

In our study, a food safety management system was developed for a chaga mushroom biotechnology product manufacturer, with the purpose of meeting the quality demands of customers and enhancing the manufacturer's reputation. The study focused on identifying the potentially significant hazards present at each stage of the production process for chaga mushroom capsule products, and on ensuring that the biotechnology company in question has fully implemented ISO22000:2018 and the HACCP methodology. The results indicate that, in the 1 year following the implementation of ISO 22000:2018, there was a statistically significant drop (P < 0.05) in the coliforms level of the tested biotechnology product samples that started in the ninth month following implementation. The rapid screening of mycotoxin, heavy metal, and pesticide residue levels also increased monitoring intensity and strengthened the periodic rotation plan, enabling control over potential problems relating to raw materials and ensuring product quality. This finding reveals the importance and necessity of rapid screening for small- and medium-sized food industry enterprises. Furthermore, 1 year after the system's implementation, the defect rate for chaga products was also observed to have declined, and the number of process flow anomalies requiring correction was also found to have decreased significantly (P < 0.05), indicating that safety and quality levels were improving and stabilizing. If implemented over a longer period of time, the food safety management system's benefits would stand out even more, and significant improvements would be observed for more monitored items. PRACTICAL APPLICATION: Few studies have touched on food safety management systems (FSMSs) developed for capsule health food products. The enterprise examined in this study had actively worked to improve its quality system and meet its customers' needs through the implementation of the FSMSs.

Subsystem Hazard Analysis on an Offshore Waste Disposal Facility

Offshore waste disposal facilities are unique marine infrastructures that exist only in a few countries. Although the existing facilities in Japan and Singapore have been successfully operated in general, there have been no investigations on the probable hazards they pose on the environment. Considering this, conceivable hazards were identified for an offshore waste disposal facility that has recently been proposed in Korea. The causes and consequences of each of the identified hazards were analyzed to seek countermeasures for reducing the environmental impact in advance. Hazards of waste disposal facilities can be classified according to their design, construction, maintenance, operation, and site utilization. For these areas, except for site utilization, subsystem hazard analysis was performed. In the initial assessment, seven elements were found to be in the extreme risk zone, 30 were in the high-risk zone, and six were in the moderate-risk zone. After applying the alternative mitigation methods, the final risk assessment resulted in 27 moderate-risk and 16 low-risk elements. Therefore, it was confirmed that the potential risks of the proposed offshore waste disposal facility were within acceptable ranges.

A Method of Justifying Confidence in the Safety of Digital Health Interventions

Digital health interventions (DHIs) enable improvements in health strategy and address health system challenges. The World Health Organization provides a formal classification for DHIs. However, safety claims, about such interventions, vary in quality and are often vague as to how they are communicated between technical, clinical experts and stakeholders. By combining the classifications with a method of safety analysis and justification, we postulate confidence in the safety of digital technology. Confidence is resulting from the application of the framework to the DHI, using defined health system challenges. The framework and derived safety justifications can be applied to any DHI. It can serve as guideline for health strategy, regulatory and standards based compliance.

Bariatric Space, Technology, and Design: A Round Table

BACKGROUND

Planning and executing healthcare for the patient or resident living with obesity can be a challenging task that has implications to the occupational health professional.

METHODS

Leading global experts in the areas of occupational health, ergonomics, bariatrics, technology, and patient care were identified and invited to participate in a round table discussion. Questions posed to experts were based on literature that addressed patient handling and mobility, architectural design recommendations, clinical care of the person with obesity, and ergonomic guidelines.

FINDINGS

Experts agreed that special considerations must be in place to care for the person who is obese. These special considerations should address not only clinical care of the patient, but ways to protect workers from occupational injury associated with clinical care. Experts suggested that, in some situations, a bariatric training suit may be helpful in better understanding space and design challenges, as well as a better understanding of the physical limitations associated with a larger body habitus (although simulated). Further, experts agreed that insensitivities often stem from failure to have proper space, technology and design accommodations in place. Conclusions/Application to Practice: The occupational health professional is a key resource to teams charged with planning and executing healthcare for the patient or resident living with obesity. Interprofessional understanding and communication can lead to a more comprehensive approach to space, design and technology that not only addresses the patient, but the worker providing direct care.

A new method for investigating the relationship between diet and mortality: hazard analysis using dietary isotopes

Background: The population of Roman Britain are renowned for having elevated nitrogen (δ¹⁵) stable isotope values, which have been interpreted as evidence for the increased consumption of marine products. However, such results are now understood to also reflect episodes of stress and disease, suggesting that new interpretations are warranted.Aim: To test a novel approach which combines hazard mortality analysis and stable isotope data to determine whether there is a relationship between age-at-death, elevated δ¹⁵N values and mortality risk.Subjects and methods: This study used published osteological and dietary stable isotope data for nitrogen (δ¹⁵N) and carbon (δ¹³C) of 659 1st-5th century AD individuals aged >12 years old excavated from Roman cemeteries in Britain. The relationship between diet and mortality risk was assessed using the Gompertz hazard model, and differences in median reported isotope values between the sexes was determined using a Mann Whitney test.Results: It was discovered that higher δ¹⁵N levels are associated with elevated risks of mortality, whereas the opposite pattern was observed for δ¹³C, and males had higher median δ¹³C and δ¹⁵N values.Conclusion: This study successfully demonstrated that stable isotope data can be integrated into hazard models, allowing one to connect diet and mortality in past populations. It supports the findings of other isotope studies which have established that individuals with childhood stress/trauma will have different isotope patterns.

A novel approach recommendation for hazard analysis

Hazard evaluation generally defines the ranking of hazards in the work environment and ignores the interaction of hazards. This article aims to overcome this drawback using a fuzzy cognitive map (FCM) approach to analyze the interaction of hazards related to sheathing tasks in a construction firm. The FCM approach can be insufficient for hazard evaluation over the long term due to certain budget and time restrictions allocated by the firm. When the firm allocates more time and budget for a process, the firm must limit the allocated time and budget for the other processes. This article aims to overcome this problem so linear programming is used to optimize the goal and resources of the firm. The article contributes to hazard evaluation of sheathing tasks in a construction firm considering the interaction of the hazards and the capacity of the firm.

Hazard analysis using a Bayesian network and linear programming

In order to make a system safer, it is necessary to determine which hazard should be removed by considering the interactions of all hazards in the process. In this study, the influence of the hazards related to iron works in a construction firm is examined by Bayesian network approach. If only the most important hazard is identified and removed from the work environment, it may be erroneous to comment on the levels of the remaining hazards. A Bayesian network is proposed to remove this problem. If there is more time and budget than planned for a process, these capacities will have to be reduced in other processes. Linear programming is proposed to remove this problem. A strong decision support system has been established by combining a Bayesian network and linear programming. A construction firm application has been demonstrated using the proposed method.

Hazard Analysis and Safety Requirements for Small Drone Operations: To What Extent Do Popular Drones Embed Safety?

Currently, published risk analyses for drones refer mainly to commercial systems, use data from civil aviation, and are based on probabilistic approaches without suggesting an inclusive list of hazards and respective requirements. Within this context, this article presents: (1) a set of safety requirements generated from the application of the systems theoretic process analysis (STPA) technique on a generic small drone system; (2) a gap analysis between the set of safety requirements and the ones met by 19 popular drone models; (3) the extent of the differences between those models, their manufacturers, and the countries of origin; and (4) the association of drone prices with the extent they meet the requirements derived by STPA. The application of STPA resulted in 70 safety requirements distributed across the authority, manufacturer, end user, or drone automation levels. A gap analysis showed high dissimilarities regarding the extent to which the 19 drones meet the same safety requirements. Statistical results suggested a positive correlation between drone prices and the extent that the 19 drones studied herein met the safety requirements generated by STPA, and significant differences were identified among the manufacturers. This work complements the existing risk assessment frameworks for small drones, and contributes to the establishment of a commonly endorsed international risk analysis framework. Such a framework will support the development of a holistic and methodologically justified standardization scheme for small drone flights.

Enhanced Hazard Analysis and Risk Assessment for Human-in-the-Loop Systems

OBJECTIVE

The objective of this study was to enhance the existing system hazard analysis (SHA) technique by introducing the concepts of human and automation reliability quantification as well as fuzzy classification of system risks. These enhancements led to formulation of a new overall system risk-reliability score.

BACKGROUND

Many system safety analysis methods focus on individual physical component failure. Some human reliability analyses (HRA) consider human-automation interaction in determining system failure rates. There is no system safety analysis technique that quantifies the impact of human and automation reliability on the risk of hazard exposure.

METHOD

Classification of the probability and severity of hazard exposure is typically made in terms of linguistic rather than numerical variables. Fuzzy sets are applicable for transforming linguistic classifications to numerical quantities. We focused on using fuzzy sets to define overlapping bands of system risk exposure with reference to the hazard risk categories defined in MIL-STD 882B. Fuzzy sets were also used for human-automated system reliability classification.

RESULTS

Introduction of human and automation reliability assessment in the SHA allows for definition of a system risk-reliability modeling space. The enhanced SHA (E-SHA) technique yields a mishap risk index, which is projected based on a composite assessment of human-automated system reliability at the time of operation. The E-SHA was compared with one of the most advanced HRA techniques.

CONCLUSION

The E-SHA technique supports broader safety control recommendations and provides comparable, if not more detailed, results than prior systems safety and HRA techniques.

Defining the end-point of mastication: A conceptual model

The great risks of swallowing are choking and aspiration of food into the lungs. Both are rare in normal functioning humans, which is remarkable given the diversity of foods and the estimated 10 million swallows performed in a lifetime. Nevertheless, it remains a major challenge to define the food properties that are necessary to ensure a safe swallow. Here, the mouth is viewed as a well-controlled processor where mechanical sensory assessment occurs throughout the occlusion-circulation cycle of mastication. Swallowing is a subsequent action. It is proposed here that, during mastication, temporal maps of interfacial property data are generated, which the central nervous system compares against a series of criteria in order to be sure that the bolus is safe to swallow. To determine these criteria, an engineering hazard analysis tool, alongside an understanding of fluid and particle mechanics, is used to deduce the mechanisms by which food may deposit or become stranded during swallowing. These mechanisms define the food properties that must be avoided. By inverting the thinking, from hazards to ensuring safety, six criteria arise which are necessary for a safe-to-swallow bolus. A new conceptual model is proposed to define when food is safe to swallow during mastication. This significantly advances earlier mouth models.

PRACTICAL APPLICATIONS

The conceptual model proposed in this work provides a framework of decision-making to define when food is safe to swallow. This will be of interest to designers of dietary foods, foods for dysphagia sufferers and will aid the further development of mastication robots for preparation of artificial boluses for digestion research. It enables food designers to influence the swallow-point properties of their products. For example, a product may be designed to satisfy five of the criteria for a safe-to-swallow bolus, which means the sixth criterion and its attendant food properties define the swallow-point. Alongside other organoleptic factors, these properties define the end-point texture and enduring sensory perception of the food.

Phytophthora community structure analyses in Oregon nurseries inform systems approaches to disease management

Nursery plants are important vectors for plant pathogens. Understanding what pathogens occur in nurseries in different production stages can be useful to the development of integrated systems approaches. Four horticultural nurseries in Oregon were sampled every 2 months for 4 years to determine the identity and community structure of Phytophthora spp. associated with different sources and stages in the nursery production cycle. Plants, potting media, used containers, water, greenhouse soil, and container yard substrates were systematically sampled from propagation to the field. From 674 Phytophthora isolates recovered, 28 different species or taxa were identified. The most commonly isolated species from plants were Phytophthora plurivora (33%), P. cinnamomi (26%), P. syringae (19%), and P. citrophthora (11%). From soil and gravel substrates, P. plurivora accounted for 25% of the isolates, with P. taxon Pgchlamydo, P. cryptogea, and P. cinnamomi accounting for 18, 17, and 15%, respectively. Five species (P. plurivora, P. syringae, P. taxon Pgchlamydo, P. gonapodyides, and P. cryptogea) were found in all nurseries. The greatest diversity of taxa occurred in irrigation water reservoirs (20 taxa), with the majority of isolates belonging to internal transcribed spacer clade 6, typically including aquatic opportunists. Nurseries differed in composition of Phytophthora communities across years, seasons, and source within the nursery. These findings suggest likely contamination hazards and target critical control points for management of Phytophthora disease using a systems approach.

A hazard analysis for a generic insulin infusion pump

BACKGROUND

Researchers at the Food and Drug Administration (FDA)/Center for Device and Radiological Health/Office of Science and Engineering Laboratories have been exploring the concept of model-based engineering as a means for improving the quality of medical device software. Insulin pumps were chosen as a research subject because their design provides the desired degree of research complexity and these types of devices present an ongoing regulatory challenge.

METHODS

Insulin pump hazards and their contributing factors are considered in the context of a highly abstract generic insulin infusion pump (GIIP) model. Hazards were identified by consulting with manufacturers, pump users, and clinicians; by reviewing national and international standards and adverse event reports collected by the FDA; and from workshops sponsored by Diabetes Technology Society. This information has been consolidated in tabular form to facilitate further community analysis and discussion.

RESULTS

A generic insulin infusion pump model architecture has been established. A fairly comprehensive hazard analysis document, corresponding to the GIIP model, is presented in this article.

CONCLUSIONS

We believe that this work represents the genesis of an insulin pump safety reference standard upon which future insulin pump designs can be based to help ensure a basic level of safety. More interaction with the diabetes community is needed to assure the quality of this safety modeling process.

Second insulin pump safety meeting: summary report

Diabetes Technology Society facilitated a second meeting of insulin pump experts at Mills-Peninsula Health Services, San Mateo, California on November 4, 2009, at the request of the Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories. The first such meeting was held in Bethesda, Maryland, on November 12, 2008. The group of physicians, nurses, diabetes educators, and engineers from across the United States discussed safety issues in insulin pump therapy and recommended adjustments to current insulin pump design and use to enhance overall safety. The meeting discussed safety issues in the context of pump operation; software; hardware; physical structure; electrical, biological, and chemical considerations; use; and environment from engineering, medical, nursing, and pump/user perspectives. There was consensus among meeting participants that insulin pump designs have made great progress in improving the quality of life of people with diabetes, but much more remains to be done.

Applying capacity analyses to psychophysical evaluation of multisensory interactions

Determining when, if, and how information from separate sensory channels has been combined is a fundamental goal of research on multisensory processing in the brain. This can be a particular challenge in psychophysical data, as there is no direct recording of neural output. The most common way to characterize multisensory interactions in behavioral data is to compare responses to multisensory stimulation with the race model, a model of parallel, independent processing constructed from the probability of responses to the two unisensory stimuli which make up the multisensory stimulus. If observed multisensory reaction times are faster than those predicted by the model, it is inferred that information from the two channels is being combined rather than processed independently. Recently, behavioral research has been published employing capacity analyses where comparisons between two conditions are carried out at the level of the integrated hazard function. Capacity analyses seem to be particularly appealing technique for evaluating multisensory functioning, as they describe relationships between conditions across the entire distribution curve, are relatively easy and intuitive to interpret. The current paper presents capacity analysis of a behavioral data set previously analyzed using the race model. While applications of capacity analyses are still somewhat limited due to their novelty, it is hoped that this exploration of capacity and race model analyses will encourage the use of this promising new technique both in multisensory research and other applicable fields.

Sensemaking of patient safety risks and hazards

In order for organizations to become learning organizations, they must make sense of their environment and learn from safety events. Sensemaking, as described by Weick (1995), literally means making sense of events. The ultimate goal of sensemaking is to build the understanding that can inform and direct actions to eliminate risk and hazards that are a threat to patient safety. True sensemaking in patient safety must use both retrospective and prospective approach to learning. Sensemaking is as an essential part of the design process leading to risk informed design. Sensemaking serves as a conceptual framework to bring together well established approaches to assessment of risk and hazards: (1) at the single event level using root cause analysis (RCA), (2) at the processes level using failure modes effects analysis (FMEA) and (3) at the system level using probabilistic risk assessment (PRA). The results of these separate or combined approaches are most effective when end users in conversation-based meetings add their expertise and knowledge to the data produced by the RCA, FMEA, and/or PRA in order to make sense of the risks and hazards. Without ownership engendered by such conversations, the possibility of effective action to eliminate or minimize them is greatly reduced.

Identification of Ergonomic-Related Hazards in an Industrial Sample Using the National Occupational Exposure Survey

The National Occupational Exposure Survey (NOES) was used to determine probabilities for 4 potential physical-agent and 10 potential ergonomic-related exposure hazards among a representative sample of U.S. industries. Potential physical-agent hazard exposures, principally whole-body and segmental vibration, were highest among railroad and heavy construction industries. Several construction industries had high probabilities of potential ergonomic-related exposure hazards, especially to the back and upper extremities. Establishments with 100 to 249 employees had the highest probability of potential exposures to the 2 types of hazards. Measures of safety and health climate did not differ consistently between high-hazard and low-hazard establishments. The approach taken in this paper may be used to help identify highrisk industries, evaluate interventions, and develop inspection strategies.

Hazards Associated with Holding and Reheating Foods at Vending Sites in a Small Town in Zambia

Hazard analyses were done at 11 cooked-food-vending sites and related food-vending operations in a small-town market along a highway in Zambia. The analyses consisted of observations and time-temperature measurements at the vending sites and interpretations of results of laboratory tests of samples of foods (including leftovers) collected after holding and reheating. Salmonellae were isolated from dried ants, a cooked meatball on display, and pumped river water used by the vendors. Ants for sale at the market contained 10⁷ Bacillus cereus cells per g. Nshima (boiled maize meal) was held at high temperatures in pans over glowing charcoal in which steam was generated throughout the entire holding period during the day, preventing bacterial growth. Large populations of B. cereus , however, were isolated from a sample left overnight at ambient room temperature. Cooked foods other than nshima were held at room or outdoor ambient temperatures throughout the day and overnight. High aerobic mesophilic colony, thermotolerant coliform and, in a few foods, Escherichia coli counts were found in foods after several hours of holding during the day of preparation and of foods held overnight. Temperatures attained during reheating were variable and sometimes would have resulted in survival of foodborne pathogens that multiplied during holding.