Causal explanations - how to generate, identify, and evaluate them

The main goal of this dissertation is to provide a solid foundation for a formalization of Inference to the Best Explanation (IBE). This foundation consists of three major components. First, an intuitively adequate and formally precise model of causal explanation. Secondly, an intuitively adequate and formally precise measure of (causal) explanatory power. And third, an intuitively adequate and formally precise criterion of proportionality that is able to identify the most appropriate level of specificity for a causal explanation. While the first component makes it possible to generate and identify causal explanations reliably, the second and third components make it possible to evaluate the strength or quality of causal explanations, which is crucial for identifying the best of a set of competing causal explanations

Multi criteria risk analysis of a subsea BOP system

The Subsea blowout preventer (BOP) which is latched to a subsea wellhead is one of several barriers in the well to prevent kicks and blowouts and it is the most important and critical equipment, as it becomes the last line of protection against blowout. The BOP system used in Subsea drilling operations is considered a Safety – Critical System, with a high severity consequence following its failure. Following past offshore blowout incidents such as the most recent Macondo in the Gulf of Mexico, there have been investigations, research, and improvements sought for improved understanding of the BOP system and its operation. This informs the need for a systematic re-evaluation of the Subsea BOP system to understand its associated risk and reliability and identify critical areas/aspects/components. Different risk analysis techniques were surveyed and the Failure modes effect and criticality analysis (FMECA) selected to be used to drive the study in this thesis. This is due to it being a simple proven cost effective process that can add value to the understanding of the behaviours and properties of a system, component, software, function or other. The output of the FMECA can be used to inform or support other key engineering tasks such as redesigning, enhanced qualification and testing activity or maintenance for greater inherent reliability and reduced risk potential. This thesis underscores the application of the FMECA technique to critique associated risk of the Subsea BOP system. System Functional diagrams was developed with boundaries defined, a FMECA were carried out and an initial select list of critical component failure modes identified. The limitations surrounding the confidence of the FMECA failure modes ranking outcome based on Risk priority number (RPN) is presented and potential variations in risk interpretation are discussed. The main contribution in this thesis is an innovative framework utilising Multicriteria decision making (MCDA) analysis techniques with consideration of fuzzy interval data is applied to the Subsea BOP system critical failure modes from the FMECA analysis. It utilised nine criticality assessment criteria deduced from expert consultation to obtain a more reliable ranking of failure modes. The MCDA techniques applied includes the technique for order of Preference for similarity to the Ideal Solution (TOPSIS), Fuzzy TOPSIS, TOPSIS with interval data, and Preference Ranking Organization Method for Enrichment of Evaluations (PROMETHEE). The outcome of the Multi-criteria analysis of the BOP system clearly shows failures of the Wellhead connector, LMRP hydraulic connector and Control system related failure as the Top 3 most critical failure with respect to a well control. The critical failure mode and components outcome from the analysis in this thesis is validated using failure data from industry database and a sensitivity analysis carried out. The importance of maintenance, testing and redundancy to the BOP system criticality was established by the sensitivity analysis. The potential for MCDA to be used for more specific analysis of criteria for a technology was demonstrated. Improper maintenance, inspection, testing (functional and pressure) are critical to the BOP system performance and sustenance of a high reliability level. Material selection and performance of components (seals, flanges, packers, bolts, mechanical body housings) relative to use environment and operational conditions is fundamental to avoiding failure mechanisms occurrence. Also worthy of notice is the contribution of personnel and organisations (by way of procedures to robustness and verification structure to ensure standard expected practices/rules are followed) to failures as seen in the root cause discussion. OEMs, operators and drilling contractors to periodically review operation scenarios relative to BOP system product design through the use of a Failure reporting analysis and corrective action system. This can improve design of monitoring systems, informs requirement for re-qualification of technology and/or next generation designs. Operations personnel are to correctly log in failures in these systems, and responsible Authority to ensure root cause analysis is done to uncover underlying issue initiating and driving failures

The Problem of Adherence in Paediatric Asthma

Non-adherence to inhaled corticosteroids (ICS) is a key barrier in asthma management. However, few studies have explored patterns of non-adherence and the reasons for variations in adherence in young people with problematic asthma. The aim of this thesis is to explore the potentially modifiable determinants of non-adherence in young people with problematic severe asthma in a tertiary care setting. This PhD comprises a systematic review of interventions to improve adherence in children with asthma; an analysis of patterns of non-adherence; a qualitative study of patients with poor adherence; and an adaptation study of the Beliefs About Medicine Questionnaire (BMQ). Each of these informs identification of interventions to improve adherence. The review found that current interventions have limited effectiveness, with only half of the included trials able to improve ICS adherence (9/18). More complex interventions, tailored to the patient, which addressed both perceptions and practical aspects of non-adherence were more likely to be effective. Secondary analysis of electronic adherence data from this population (n=93) identified adherence patterns which have implications for intervention development. The interview study (n=20) identified perceptual determinants (e.g. poor understanding of asthma and ICS) and practical determinants (e.g. no routine and forgetfulness) of non-adherence. These findings informed an adaption of the BMQ to identify beliefs underlying treatment non-adherence in this population; initial piloting (n=30) revealed high overall internal reliability but further research is needed to validate the questionnaire. This PhD highlights the need for a tailored intervention for non-adherent young people with problematic asthma which addresses perceptual and practical barriers to adherence. The PhD identified new barriers to adherence including key differences between adults and young children. A belief-based questionnaire could be used to identify modifiable beliefs for inclusion in a tailored intervention addressing both perceptual and practical barriers for adherence to ICS

Pharmacists as the delivery channel for adherence support in asthma

Non-adherence to inhaled corticosteroids remains a key challenge in asthma care in the United Kingdom (UK) – it increases healthcare costs, morbidity, and mortality. The growing pressure on UK primary care increased interest in pharmacists as a potential delivery channel for adherence support. However, research on UK pharmacist-led adherence support for asthma is limited. // This thesis addresses the gap in the literature by examining the effectiveness of previous pharmacist-led interventions in improving adherence in adults with asthma (systematic review/meta-analysis, 11 studies), exploring the perspectives of UK pharmacists (online questionnaire, n = 127) and adults with asthma (qualitative study, n = 17) on pharmacist-led adherence support for asthma, and assessing the feasibility and acceptability of a new pharmacist-led adherence support intervention delivered to adults with asthma in general practice (before-and-after study, n = 31). // Previous pharmacist-led interventions significantly improved adherence in adults with asthma (d = 0.49, 95% CI 0.35 – 0.64, p < 0.0001), with effective interventions addressing the ability and motivation to adhere to medication. UK pharmacists reported feeling most confident in and focusing mostly on patient education as adherence support (i.e. ability-related processes). Adults with asthma used their trust in other healthcare professionals (e.g. general practitioners) to gauge their trust in pharmacists. While they were open to pharmacist-led support due to gaps in existing asthma care, they were also concerned about pharmacist competency and role overlap with other healthcare professionals. The new pharmacist-led adherence intervention delivered in general practice demonstrated high acceptability among pharmacists and adults with asthma, but further work is needed to improve the feasibility of the study design. // This research suggests that pharmacist-led adherence support is worth exploring further. With additional adherence-focused support/training for pharmacists and public awareness of pharmacist-led care, UK pharmacists may be able to make a valuable contribution to asthma care

Evolutionary Psychological Influences on the Contemporary Causes of Terrorist Events

In this chapter we integrate the concept of ultimate causation derived from evolutionary psychology (i.e., why have human behavioural tendencies evolved the way they did?) with the proximal situational perspective of causal mechanisms and goals (i.e. immediate causes of behaviour and events), with the view to better understand, predict and prevent terrorist behaviour and events. The developmental perspective, while important, is not central to our current analysis. Those working in crime science, and more especially situational crime prevention, have only recently begun to show an interest in terrorism, while to the best of our knowledge there appears to be little research linking situational theories, EP and crime or terrorist behaviour. It is our contention that EP has something useful to say about how we respond to and act on information in the immediate environment, and that a better appreciation of evolutionary influences on person-situation interactions might helpfully inform efforts to reduce the proximal causes of crime and terrorist behaviour or disrupt criminals'/terrorists' proximally-active, tactical goals. The chapter is structured as follows. We begin by setting out some prevalent misconceptions about EP that we argue account for the lack of interest in the approach among terrorist researchers, and that need to be dispelled before we can proceed with our proposed analysis. Next, we set out the parameters of our analysis, and describe terrorism in a manner that is amenable to an evolutionary perspective. Given the difficulties in defining terrorism, we select the concept of tribalism as a significant exemplar of a terrorism-supporting mechanism and our focus for analysis. We move then to the main goal of this chapter: integrating the proposed causes of terrorist behaviour, from ultimate causes rooted in our evolutionary past to proximal causes and goals in the immediate environment. This analysis is conducted within the framework of the Conjunction of Terrorist Opportunity, a conceptual model that seeks to link a range of situational and offender-based, proximal causes of terrorist events. We conclude by reflecting on the implications of our exercise for research and prevention

“Knowing how” is not enough: a mixed methods exploration of inhaler technique maintenance in patients with asthma

Incorrect inhaler technique maintenance is a persistent problem amongst asthma patients, contributing to poor asthma control. Why inhaler technique deteriorates, even in the absence of identifiable barriers, is unknown. Gaining insight into this problem was the driver behind this thesis. The first study in this thesis identified that patients who were more likely to maintain correct inhaler technique were more likely to: 1) be using a DPI instead of pMDI, 2) have better baseline asthma control, and 3) have higher baseline motivation to practice correct technique [X2 (N=125,3)=16.22, p=0.001]. For the first time, the important role that patient psychosocial factors may play in inhaler technique maintenance was shown. The second study in this thesis provided further insight into relationships between patient psychosocial and behavioural factors in the context of inhaler technique maintenance. Influential factors on patient motivation to maintain correct inhaler technique included: the motivation to engage in asthma management; the motivation to self-manage via a preventative-medication based approach; self-management self-efficacy; and health care professionals’ input. Ensuring optimal inhaler technique maintenance may lie in more holistic approaches to inhaler technique interventions that address, not only physical skill related barriers, but also patient psychosocial barriers in technique maintenance

The Burden of Self-Reported Rhinitis and Associated Risk for Exacerbations with Moderate-Severe Asthma in Primary Care Patients

Acknowledgments: The iHARP database was funded by unrestricted grants from Mundipharma International Limited and Optimum Patient Care Global Ltd, which is a social enterprise that focuses on quality improvement in clinical practice. The sponsor was not involved in data analysis or the interpretation of the results.Peer reviewedPublisher PD

Inhaler devices: Do patients have a preference and does it make a difference?

The aim of this study was to assess participants perceptions and preferences for inhaler devices; and the relationship of inhaler technique to the decision making process. A mixed-methods approach including a semi-structured interview, Patient Satisfaction and Preference Questionnaire (PASAPQ) and inhalation technique assessment were employed. A total of 25 participants with at least one inhaler were recruited. The interviews analyzed qualitatively. In addition, each participant received a score for PASAPQ in regards to satisfaction with performance, satisfaction with convenience and overall satisfaction. Participants’ inhalation technique was assessed. Two matrices were generated to identify any patterns of association between participants perception from qualitative interviews, with participants satisfaction and preference (PASAPQ) with regards to correct and incorrect use of inhalers. Triangulation of data revealed that there did not appear to be a relationship between patient satisfaction with inhaler device, preference, inhalation technique and level of choice in decision making. There are other factors influencing patient opinions of inhaler devices rather than physical features of inhalers including the level of asthma control, effectiveness of medication in relieving asthma symptoms and length of time of use of inhalers. Participants did not differentiate the device from medication and this affected not only their perception about inhaler devices but also their perception about inhalation technique. This research further highlights the lack of understanding of the relevant role of inhaler devices in asthma management

Inhaler devices: Do patients have a preference and does it make a difference?

The aim of this study was to assess participants perceptions and preferences for inhaler devices; and the relationship of inhaler technique to the decision making process. A mixed-methods approach including a semi-structured interview, Patient Satisfaction and Preference Questionnaire (PASAPQ) and inhalation technique assessment were employed. A total of 25 participants with at least one inhaler were recruited. The interviews analyzed qualitatively. In addition, each participant received a score for PASAPQ in regards to satisfaction with performance, satisfaction with convenience and overall satisfaction. Participants’ inhalation technique was assessed. Two matrices were generated to identify any patterns of association between participants perception from qualitative interviews, with participants satisfaction and preference (PASAPQ) with regards to correct and incorrect use of inhalers. Triangulation of data revealed that there did not appear to be a relationship between patient satisfaction with inhaler device, preference, inhalation technique and level of choice in decision making. There are other factors influencing patient opinions of inhaler devices rather than physical features of inhalers including the level of asthma control, effectiveness of medication in relieving asthma symptoms and length of time of use of inhalers. Participants did not differentiate the device from medication and this affected not only their perception about inhaler devices but also their perception about inhalation technique. This research further highlights the lack of understanding of the relevant role of inhaler devices in asthma management