Effectiveness measurement, safety decision

Although a hazard analysis and a risk assessment would result from applying the preceding outline, good management requires that the remaining steps in The Safety Decision Hierarchy be taken, which are—decide and take action, and measure for effectiveness. 

The cost-effectiveness analysis is a well established discipline. There is, however, a gap between the theoretical cost-effectiveness analysis and the practical implementation of the tool as decisionmaking support. Ideally, the decision-maker should have a number of methods at hand. Some of these should be detailed and sophisticated and being used when a few safety measures are compared and the consequences of unfavourable decisions are severe. On the other hand we also need simplified methods to sort out some cost-effective measures from many alternatives in less complicated comparison studies or in pre-studies to more sophisticated comparisons. 

In the evaluation of safety measures a cost-effectiveness analysis may be adopted. A cost-effectiveness analysis compares the costs and the effects of a decision alternative, where the cost is measured in monetary terms and the effects are measured in natural units, such as lives saved, see e.g. Boardman et al 2006, Baron 2000 and Petitti 2000. 

In order to compare the cost-effectiveness of the two measures, the cost-effectiveness ratio for both measures is calculated. The cost-effectiveness ratio for safety measures 1 and 2 is equal to C /Z and C2/Z2, respectively. Safety measure 1 is more cost-effective than safety measure 2 if Ci/Z < C2IZ2. To see whether safety measure 1 is preferred to status quo or not, the cost-effectiveness ratio has to be compared with a reference value, R. The reference value clarifies how much money the decision-maker is willing to pay to obtain one unit of effectiveness. Implementation of the safety measure is preferred to status quo if the decision-maker is willing to pay more to obtain one unit of effectiveness than the cost-effectiveness index expresses, which means that safety measure 1 is preferred to status quo if / > (C,/Z,). 

Develop Remediation Proposals. When the results of the risk assessment indicate that risk elimination or reduction measures are to be taken, alternate proposals for the design and operational changes necessary to achieve an acceptable risk level would be recommended. In their order of effectiveness, the actions as shown in Chapter 12, Hierarchy of Controls The Safety Decision Hierarchy, would be the basis on which remedial proposals are made. For each proposal, the remediation cost would be determined and an estimate of its effectiveness in achieving risk reduction given. Risk elimination or reduction methods would then be selected and implemented. 

Provisions in Section 7.1 of ZIO, Management Review Process, require that systems be in place to measure the effectiveness of the risk reduction measures taken. Those provisions are relative to the measurement of effectiveness and re-analyzing steps in The Safety Decision Hierarchy. Assuring that the actions taken accomplish what was intended is an integral step in the PDCA process. Followup activity would determine that the ... 

Probabilistic safety analysis was used to support the deterministic analysis with regard to the elimination of weak points of the design and an effectiveness assessment of decisions on the perfection of safety features and measures, i.e., to ensure a more balanced defence-in-depth approach. 

Example 1 Aircraft safety, which includes the system of measures to minimize or eliminate risks generated by, for example, a wrong decision made by a pilot when operating a plane, the malfunction of the safety device onboard, or the errors of the gronnd crew. One of the possible effective measures to minimize this kind of fanlt is the application of redundant systems within airplane control systems. 

Deciding which risk-reduction method to use maybe difficult. In many instances, appropriate decisions can be made without resorting to quantitative techniques. However, in some cases, particularly when the options are costly, quantitative risk analysis (QRA) and risk-based decision-making approaches may be an effective basis for measuring the improvement in safety arising from the proposed options. These approaches can also be used in prioritizing safety improvements and balancing cost and production issues. 

In order to associate a number to represent the utility of these four outcomes we have to choose between several types of economic evaluations, basically between cost-effectiveness analysis, cost-utility analysis and cost-benefit analysis. The first of these is ruled out because it measures the health outcome in natural units. Given that the side effects of drags are of a varied nature, we need to be able to aggregate the different seriousness of these side effects in order to obtain a single utility, at least for the NSEA event. Furthermore, this utility must be comparable with that of, for example, the SER event. This is not possible with cost-effectivity. If we chose cost-utility, the utility associated with each event would be measured in QALYs gained or lost in each option. As QALYs are a universal measure of health benefit, cost-utility analysis could be appropriate for this type of decision. Lastly, cost-benefit analysis would also be appropriate, as it measures the utilities associated with each outcome in monetary terms, which reflect the willingness to pay for one of the outcomes in terms of safety and effectiveness. 

To prevent a possible alignment of holes in safety barriers, company C has as opposed to companies A and B, severe risk constraints present, which strictly require additional safety measures to be implemented when holes are identified in a safety barrier, as illustrated by the number of positively affected safety barriers in the other two companies. Moreover, in company C safety critical decisions are made on the highest level, creating an overview and also commitment of all employees to identify, report and reduce risks as soon and as effectively as possible. 

After such deviations are defined, for each individual point the possible reasons and effects are to be considered. Finally, it can be ascertained whether the available measures are sufficient, or additional ones are required. Important for the efficiency of such an analysis is the experience of the team in charge. The members of this team should consist of experts in production, process engineering, control systems, and relevant authorities such as the TUV. Carefully executed safety analyses are decisive for the elaboration of control systems, interlocking systems, malfunction lists and, in general, for the operation handbook. 

Quality me a.t are merit and improvement requires developing and testing quality measures and investigating the best ways to collect, compare, and communicate these data so they are useful to decision makers. AHRQ s research emphasizes studies of the most effective ways to implement these measures and strategies in order to improve patient safety and healthcare quality. 

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