How useful is the DSM-5 severity indicator in bulimia nervosa? A clinical study including a measure of impairment

The severity criterion used in DSM-5 for bulimia nervosa (BN) was investigated in 214 individuals referred for treatment at a regional eating disorders service in the UK. In addition to comparing eating disorder symptoms, impairment secondary to these symptoms was also assessed. According to guidance in DSM-5, 94 individuals were classified as mild (43.9%), 70 as moderate (32.7%), 32 as severe (15.0%), and 8 as extreme (3.7%) levels of BN severity. Due to small numbers in the latter two groups, it was necessary to combine these to form one ‘severe/extreme’ group. Analyses on these three groups suggested no group effect on demographic variables but differences were seen on measures of eating pathology, psychological distress, and psychosocial impairment between the mild group and other groups. Individuals in the moderate and severe/extreme groups scored comparably on most measures of pathology and impairment. The results are broadly consistent with past studies on community samples although together question the demarcation between moderate and more severe groups of individuals with BN

An exploration of childhood obesity treatment interventions to enhance their long-term effectiveness.

Childhood obesity is a major public health concern. Recent data suggests although childhood obesity prevalence rates appear to be slowing, they are still unacceptably high (Health Survey for England, 2010). To establish a downward trend in childhood obesity rates, effective treatment options are vital. To date, multi-component treatment interventions (MCTIs) incorporating a physical activity, healthy eating and behavioural component and encouraging family involvement appear to be the most promising approach to treat childhood obesity. However, no firm conclusion can be made regarding the sustainability of treatment outcomes (i.e. behavioural & weight related outcomes) (Luutikhuis et al., 2009). This thesis contributed to the evidence base regarding the sustainability of treatment outcomes from MCTIs; considered stakeholder views in the intervention design process and provided an insight into treatment recipient's reasons for attrition from MCTIs.To critically examine the evidence base, Study 1 provided a systematic review of childhood obesity treatment interventions. Results revealed gaps in the evidence in terms of how best to maintain treatment outcomes. Furthermore the study highlighted a need to better consider stakeholder views in intervention design and to fully report treatment fidelity (TF). In Study 2, a qualitative inquiry explored stakeholder perspectives towards childhood obesity treatment and the maintenance of treatment outcomes. Results revealed incongruence between treatment recipients (i.e. parents & children) and treatment deliverers (i.e. health professionals). Treatment recipients suggested they required ongoing support to maintain treatment outcomes. Conversely, treatment deliverers suggested ongoing support is unrealistic and MCTIs should create autonomous individuals who feel confident in their ability to maintain treatment outcomes. Implications included the need to consider maintenance strategies that promote autonomous motivations and perceived competence for behavioural changes in participants with the aim of improving weight maintenance following MCTIs.In light of stakeholder views in Study 2, Study 3A detailed a pilot study to test the efficacy of a maintenance intervention underpinned by Self Determination Theory (Deci & Ryan, 1985; 2000) and that integrated Motivational Interviewing (Miller & Rollnick, 1991; 2002) and cognitive behavioural strategies to improve the sustainability of behavioural and weight related outcomes following a MCTI. A secondary aim of Study 3A was to evaluate TF. Findings supported the potential importance of autonomous motivation and perceived competence in enhancing the maintenance of behavioural and weight related changes. Furthermore this study highlighted a need to explore participants' reasons for attrition from MCTIs. Study 3B provided a qualitative exploration of parents and children's reasons for attrition from MCTIs. Findings underlined the complexity of attrition with several psychological and motivational reasons appearing as the driving source for attrition. Study implications included the need to consider individual families' needs within MCTIs, targeting parents and children's motivations for maintaining a healthy lifestyle and weight differently. The collective implications of the four studies included the need for stakeholders to be involved at all levels of design, implementation and evaluation of MCTIs, the need to assess and report all aspects of TF and the need for MCTIs to develop families' perceived competence and autonomous motivations for health behaviour changes in order to improve the sustainability of weight related outcomes

A Game Theoretical Method for Cost-Benefit Analysis of Malware Dissemination Prevention

Copyright © Taylor & Francis Group, LLC. Literature in malware proliferation focuses on modeling and analyzing its spread dynamics. Epidemiology models, which are inspired by the characteristics of biological disease spread in human populations, have been used against this threat to analyze the way malware spreads in a network. This work presents a modified version of the commonly used epidemiology models Susceptible Infected Recovered (SIR) and Susceptible Infected Susceptible (SIS), which incorporates the ability to capture the relationships between nodes within a network, along with their effect on malware dissemination process. Drawing upon a model that illustrates the network’s behavior based on the attacker’s and the defender’s choices, we use game theory to compute optimal strategies for the defender to minimize the effect of malware spread, at the same time minimizing the security cost. We consider three defense mechanisms: patch, removal, and patch and removal, which correspond to the defender’s strategy and use probabilistically with a certain rate. The attacker chooses the type of attack according to its effectiveness and cost. Through the interaction between the two opponents we infer the optimal strategy for both players, known as Nash Equilibrium, evaluating the related payoffs. Hence, our model provides a cost-benefit risk management framework for managing malware spread in computer networks

Distinguishing factors that influence attendance and behaviour change in family‐based treatment of childhood obesity: a qualitative study

ObjectivesFor the effective treatment of childhood obesity, intervention attendance and behaviour change at home are both important. The purpose of this study was to qualitatively explore influences on attendance and behaviour change during a family-based intervention to treat childhood obesity in the North West of England (Getting Our Active Lifestyles Started (GOALS)).DesignFocus groups with children and parents/carers as part of a broader mixed-methods evaluation.MethodsEighteen focus groups were conducted with children (n = 39, 19 boys) and parents/carers (n = 34, 5 male) to explore their experiences of GOALS after 6 weeks of attendance (/18 weeks). Data were analysed thematically to identify influences on attendance and behaviour change.ResultsInitial attendance came about through targeted referral (from health care professionals and letters in school) and was influenced by motivations for a brighter future. Once at GOALS, it was the fun, non-judgemental healthy lifestyle approach that encouraged continued attendance. Factors that facilitated behaviour change included participatory learning as a family, being accountable and gradual realistic goal setting, whilst challenges focussed on fears about the intervention ending and a lack of support from non-attending significant others.ConclusionsFactors that influence attendance and behaviour change are distinct and may be important at different stages of the family’s change process. Practitioners are encouraged to tailor strategies to support both attendance and behaviour change, with a focus on whole family participation within and outside the intervention

An exploration of childhood obesity treatment interventions to enhance their long-term effectiveness

Childhood obesity is a major public health concern. Recent data suggests although childhood obesity prevalence rates appear to be slowing, they are still unacceptably high (Health Survey for England, 2010). To establish a downward trend in childhood obesity rates, effective treatment options are vital. To date, multi-component treatment interventions (MCTIs) incorporating a physical activity, healthy eating and behavioural component and encouraging family involvement appear to be the most promising approach to treat childhood obesity. However, no firm conclusion can be made regarding the sustainability of treatment outcomes (i.e. behavioural & weight related outcomes) (Luutikhuis et al., 2009). This thesis contributed to the evidence base regarding the sustainability of treatment outcomes from MCTIs; considered stakeholder views in the intervention design process and provided an insight into treatment recipient's reasons for attrition from MCTIs. To critically examine the evidence base, Study 1 provided a systematic review of childhood obesity treatment interventions. Results revealed gaps in the evidence in terms of how best to maintain treatment outcomes. Furthermore the study highlighted a need to better consider stakeholder views in intervention design and to fully report treatment fidelity (TF). In Study 2, a qualitative inquiry explored stakeholder perspectives towards childhood obesity treatment and the maintenance of treatment outcomes. Results revealed incongruence between treatment recipients (i.e. parents & children) and treatment deliverers (i.e. health professionals). Treatment recipients suggested they required ongoing support to maintain treatment outcomes. Conversely, treatment deliverers suggested ongoing support is unrealistic and MCTIs should create autonomous individuals who feel confident in their ability to maintain treatment outcomes. Implications included the need to consider maintenance strategies that promote autonomous motivations and perceived competence for behavioural changes in participants with the aim of improving weight maintenance following MCTIs. In light of stakeholder views in Study 2, Study 3A detailed a pilot study to test the efficacy of a maintenance intervention underpinned by Self Determination Theory (Deci & Ryan, 1985; 2000) and that integrated Motivational Interviewing (Miller & Rollnick, 1991; 2002) and cognitive behavioural strategies to improve the sustainability of behavioural and weight related outcomes following a MCT!. A secondary aim of Study 3A was to evaluate TF. Findings supported the potential importance of autonomous motivation and perceived competence in enhancing the maintenance of behavioural and weight related changes. Furthermore this study highlighted a need to explore participants' reasons for attrition from MCTIs. Study 3B provided a qualitative exploration of parents and children's reasons for attrition from MCTIs. Findings underlined the complexity of attrition with several psychological and motivational reasons appearing as the driving source for attrition. Study implications included the need to consider individual families' needs within MCTIs, targeting parents and children's motivations for maintaining a healthy lifestyle and weight differently. The collective implications of the four studies included the need for stakeholders to be involved at all levels of design, implementation and evaluation of MCTIs, the need to assess and report all aspects of TF and the need for MCTIs to develop families' perceived competence and autonomous motivations for health behaviour changes in order to improve the sustainability of weight related outcomes.EThOS - Electronic Theses Online ServiceGBUnited Kingdo