Risk analysis, scoring system

Risk is determined by assessing its two components the severity of harm or damage resulting from a hazard-related event and the probability that the event could occur. Table 15.1 presents a sample Risk Assessment Matrix, illustrating how these two factors are combined to obtain a risk level. A review of the many published risk assessment matrices appears in chapters titled A Primer On Hazard Analysis And Risk Assessment and Risk Scoring Systems in this authors book titled Innovations In Safety Management. 

For such a self-analysis, a survey mechanism is necessary. An outline of a basic survey guide follows. For the survey mechanism to relate to the hazards and risks in a particular operation, it is necessary that management, assisted by a safety professional, add or delete items. Also, a scoring system for each item, compatible with practices in the organization, should be included in any revision of the guide so that a compilation of results can be made. In many situations, a simple yes , no , and not applicable scoring system will suffice. I must emphasize—this guide is not offered as a one-size-fits-all mechanism. 

B155.1 s Subsection 6.4, Assess Initial Risk, says that risks shall be assessed using a risk scoring system. The Example Risk-Scoring System shown in the standard is taken from MIL-STD-882D. It is identical to the Risk Assessment Matrix depicted in Table 7 in Chapter 8, A Primer on Hazard Analysis and Risk Assessment, and shown here as Table 4. 

An Internet search will also show that numerous ergonomics risk assessment and risk scoring systems have been developed, and their use is recommended. Bruce Lyon of the Hays Companies and Georgi Popov who is at the University of Central Missouri have given permission to duplicate an Ergonomic Task Analysis Scoring Tool— Initial Evaluation (see Figure 20.1). They say this about it ... 

Cardiovascular A meta-analysis and systemic review were performed to ascertain the relationship between prior warfarin use with subtherapeutic international normalized ratio (INR) and outcome after intravenous or intraarterial thrombolytic therapy in acute ischaemic stroke patients The outcomes were symptomatic intracranial haemorrhage, modified Rankin scale score and mortality. The risk of symptomatic intracranial haemorrhage after thrombolytic therapy was increased in patients using warfarin with subtherapeutic INR levels. However, there was no association between prior warfarin therapy and worsened fxmctional outcome or all-cause death. 

In fact, there is wide variation in the points of emphasis of the various standardized auditing systems. Kuusisto divides the areas of inquiry into four broad categories policy, organization, and administration hazard control and risk analysis motivation, leadership, and training and monitoring, statistics, and reporting. Which components are emphasized in the final score depends on the system. Kuusisto describes the differing emphases of three systems in Table 7.2. 

The marine industry is recognising the need for powerful techniques that can be used to perform risk analysis of marine systems. One technique that has been applied in both national and international marine regulations and operations is Failure Mode and Effects Analysis (FMEA). This risk analysis tool assumes that a failure mode occurs in a system/component through some failure mechanism. The effect of this failure is then evaluated. A risk ranking is produced in order to prioritise the attention for each of the failure modes identified. The traditional method utilises the Risk Priority Number (RPN) ranking system. This method determines the RPN by finding the multiplication of factor scores. The three factors considered are probability of failure, severity and detectability. Traditional FMEA has been criticised to have several weaknesses. These weaknesses are addressed in this Chapter. A new approach, which utilises the fuzzy rules base and grey relation theory, is presented. 

The main advantage of SVM over other data analysis methods is its relatively low sensitivity to data overfitting, even with the use of a large number of redundant and overlapping molecular descriptors. This is due to its reliance on the structural risk minimization principle. Another advantage of SVM is the ability to calculate a reliability score, R-value, which provides a measure of the probability of a correct classification of a compound [70], The R-value is computed by using the distance between the position of the compound and the hyperplane in the hyperspace. The expected classification accuracy for the compound can then be obtained from the 7 -value by using a chart which shows the statistical relationship between them. As with other methods, SVM requires a sufficient number of samples to develop a classification system and irrelevant molecular descriptors may reduce the prediction accuracies of the SVM classification systems. 

Nervous system The impact of tranexamic acid on seizures after cardiac surgery was evaluated [67. Tranexamic acid has proconvulsant properties that may be associated with postoperative seizures. A retrospective analysis of 5958 consecutive cardiac surgery patients identified several factors significantly associated with an increas risk of postoperative seizures tranexamic acid exposure, preoperative cardiac arrest, preoperative neurological disease, open chamber surgery, cardiopulmonary bypass time >150 min., previous cardiac surgery and an Acute Physiology, Age, and Chronic Health Evaluation II (APACHE) score >20. Thus, tranexamic acid use may present a readily modifiable risk factor for postoperative seizures. 

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