Epistemic divides and ontological confusions: The psychology of vaccine scepticism

Vaccine scepticism is an increasingly important barrier to optimal coverage in developed countries. In this commentary, we make the case that negative attitudes towards vaccines reflect a broader and deeper set of beliefs about health and wellbeing. We suggest that this alternative worldview is influenced by ontological confusions (e.g. regarding purity, natural energy), and knowledge based on personal lived experience and trusted peers, rather than the positivist epistemological framework. Our view is supported by recent social-psychological research, including strong correlations of vaccine scepticism with adherence to complementary and alternative medicine, magical health beliefs, and conspiracy ideation. For certain well-educated and well-resourced individuals, opposition to vaccines represents an expression of personal intuition and agency, in achieving a positive and life-affirming approach to health and wellbeing. These core beliefs are not amenable to change - and especially resistant to communications from orthodox, authoritative sources. Although this view does suggest tactical improvements to messaging, we suggest that a better long-term strategy is to combine with other disciplines in order to address the root causes of vaccine scepticism. Vaccine scepticism is unlikely to thrive in a cultural context that trusts and values the scientific consensus. © 2018, © 2018 Taylor & Francis Group, LLC

A geometric approach to non-parametric density estimation

A novel non-parametric density estimator is developed based on geometric principles. A penalised centroidal Voronoi tessellation forms the basis of the estimator, which allows the data to self-organise in order to minimise estimate bias and variance. This approach is a marked departure from usual methods based on local averaging, and has the advantage of being naturally adaptive to local sample density (scale-invariance). The estimator does not require the introduction of a plug-in kernel, thus avoiding assumptions of symmetricity and morphology. A numerical experiment is conducted to illustrate the behaviour of the estimator, and it’s characteristics are discussed

Regularized tessellation density estimation with bootstrap aggregation and complexity penalization

Locally adaptive density estimation presents challenges for parametric or non-parametric estimators. Several useful properties of tessellation density estimators (TDEs), such as low bias, scale invariance and sensitivity to local data morphology, make them an attractive alternative to standard kernel techniques. However, simple TDEs are discontinuous and produce highly unstable estimates due to their susceptibility to sampling noise. With the motivation of addressing these concerns, we propose applying TDEs within a bootstrap aggregation algorithm, and incorporating model selection with complexity penalization. We implement complexity reduction of the TDE via sub-sampling, and use information-theoretic criteria for model selection, which leads to an automatic and approximately ideal bias/variance compromise. The procedure yields a stabilized estimator that automatically adapts to the complexity of the generating distribution and the quantity of information at hand, and retains the highly desirable properties of the TDE. Simulation studies presented suggest a high degree of stability and sensitivity can be obtained using this approach

Prevalence of gambling-related harm provides evidence for the prevention paradox

Background: The prevention paradox (PP) describes a situation in which a greater number of cases of a disease-state come from low-risk members of a population, because they are more prevalent than high-risk members. Past research has provided only tangential and disputed evidence to support the application of the PP to gambling-related harm. Aims: To assess whether the PP applies to gambling, the prevalence of a large set (72) of diverse harmful consequences from gambling was examined across four risk categories for problem gambling, including no-risk, low-risk, moderate-risk, and problem-gambling. Methods: Respondents who had gambled on non-lottery forms in the past 6 months completed an online survey (N = 1,524, 49.4% male). The data were weighted to the known prevalence of gambling problems in the Victorian community. Results: The prevalence of gambling harms, including severe harms, was generally higher in the combined categories of lower risk categories compared to the high-risk problem-gambling category. There were some notable exceptions, however, for some severe and rare harms. Nevertheless, the majority of harms in the 72-item list, including serious harms such as needing temporary accommodation, emergency welfare assistance, experiencing separation or end of a relationship, loss of a job, needing to sell personal items, and experiencing domestic violence from gambling, were more commonly associated with lower risk gamblers. Conclusion: Many significant harms are concentrated outside the ranks of gamblers with a severe mental health condition, which supports a public-health approach to ameliorating gambling-related harm. © 2018 The Author(s

Measuring behavioural dependence in gambling: A case for removing harmful consequences from the assessment of problem gambling pathology

Behavioural dependence (BD) for gambling has traditionally been subsumed under the concept of ‘problems’: a hybrid construct that includes both indicators of BD, and adverse consequences (harm) arising from excessive time and money expenditure. Although progress has been made towards specific measurement of harm, dedicated measures of BD do not exist. Theory led us to expect that (1) dependence and harm are measurably distinct constructs, (2) harm mediates the relationship between dependence and wellbeing, and finally, that (3) separate measures should be more effective than a unidimensional problems measure in predicting wellbeing. Candidate BD items from six existing measures of gambling problems were extracted and evaluated with respect to DSM-5 criteria and content overlap, leading to 17 candidate items. This was further reduced to 8 items based on both item content and psychometric criteria, using data from an online panel of 1524 regular gamblers, with demographic characteristics similar to Australian population norms. Participants also completed measures of harm, problems, and subjective wellbeing. All three hypotheses were confirmed. BD was shown to be highly reliable and unidimensional, and measurably distinct from gambling harms. Harm mediated the negative relationship between BD and wellbeing. The harm + BD model yielded better predictions of personal wellbeing that a unidimensional, continuous problems measure—and explained about twice the variance of a simple contrast between problem and non-problem gamblers. We conclude that is psychometrically justified to specifically measure gambling BD, and this may be of particular use in theoretically-driven applications. © 2019, Springer Science+Business Media, LLC, part of Springer Nature

The dangers of conflating gambling-related harm with disordered gambling: Commentary on: Prevention paradox logic and problem gambling (Delfabbro & King, 2017)

In their critical review of the prevention paradox (PP) applied to gambling-related harm, Delfabbro and King (2017) raise a number of concerns regarding specific assumptions, methods, and findings as well as the general conceptual approach. Besides discussing the PP, the review also considers the merits of considering a "continuum of harm," as opposed to the more traditional categorical approach to classifying problem gamblers. Their critique is carefully modulated and balanced, and starts a useful dialogue in the context of a public health approach to gambling. Unfortunately, some of Delfabbro and King's (2017) arguments rest on the treatment of gambling harm as a binary state and conflates gambling-related harm with disordered gambling. In this reply, we argue that the application of PP logic to gambling harm has not yet been addressed by us, and is only indirectly related to the more important objective of understanding how gambling can reduce ones' quality of life. © 2017 The Author(s)

Then and now: Consumption and dependence in e-cigarette users who formerly smoked cigarettes

Electronic cigarette use, or vaping, continues to be a focus for regulators and policy makers in public health, particularly since it can compete with or be a substitute for smoking. This study investigated characteristics of nicotine dependence and consumption in a sample of vapers who formerly smoked cigarettes. We recruited 436 (80% male) vapers from several internet discussion forums; 95% of whom previously smoked, but ceased after commencing vaping. These participants completed a retrospective version of the Fagerström Test for Nicotine Dependence (FTND-R), as well as a version modified to suit current vaping (FTND-V), along with measures of consumption. Nicotine dependence appears to reduce markedly when smokers transition to vaping. However, ‘decoupling’ is observed in the relationship between consumption and dependence in vaping, and the FTND-V showed inadequate psychometric properties. Older and female vapers tend to employ a low-power, higher nicotine-concentration style of vaping. Overall, nicotine concentration tended to increase over time, although this effect was moderated by users' intentions to reduce their intake. Indicators of smoking addiction do not appear to be applicable to vaping, with respect to both internal consistency and relationship to consumption. This suggests that motivations for vaping are less dominated by nicotine delivery (negative reinforcement), and may be driven more by positive reinforcement factors. Nevertheless, e-liquid nicotine concentration was associated, albeit weakly, with dependence among e-cigarette users. Finally, vapers are heterogeneous group with respect to style of consumption, with a high-power/lower nicotine set-up more common among younger men. © 2017 Elsevier Lt

Adaptive wavelet filtering for analysis of event-related potentials from the electro-encephalogram

A challenging task in psychophysiology is the extraction of event-related potentials (ERPs) from the background electro-encephalogram. The task is made more difficult by the properties of ERPs, which typically consist of multiple features of variable latency, localised in time and frequency. A novel technique is described for analysis of ERPs, adaptive wavelet filtering (AWF), which is proposed as an alternative to trial averaging. Band-limited detail representations of each trial are obtained using wavelet analysis. The Woody adaptive filter is then used to align trials with respect to the evoked response. In a simulation study, the AWF extracts 39% of higher-frequency signal variance from background noise, compared with less than 1% for standard averaging and the Woody filter. The AWF is applied to a data-set of 448 ERPs, comprising right-finger button presses from eight subjects. Average split-half reliability of the AWF on scales up to 12Hz was 0.51

Internalized and externalized continuing bonds in bereaved parents : their relationship with grief intensity and personal growth

Continuing bonds (CB) expression appears especially prevalent among bereaved parents. This study examined the relationship between CB and grief outcomes for this population. A customized CB scale for use with bereaved parents was derived from the literature. 354 participants (10 male) recruited from online support groups completed an internet questionnaire. A three factor dimensional structure of CB (internalized, externalized, and transference) was supported. Structural equation modeling showed clear links between internalized bonds and a more positive grief status; externalized bonds showing an opposite relationship. Weaker effects were found for child's age, time since death, and type of death

Development and evaluation of the R-I-CAM-Q as a brief summative measure of CAM utilisation.

OBJECTIVE: This study evaluates a revised version of the I-CAM-Q, the R-I-CAM-Q, which is a shorter scale, and suitable for use as a brief, summative measure of CAM utilisation. DESIGN: Online survey with an Australian sample (n=2697). ANALYSIS: The psychometric properties of the I-CAM-Q were analysed using Mokken Scaling Analysis and Structural Equation Modelling. RESULTS: A subset of items were identified as having an adequate uni-dimensional structure that can be aggregated to yield a scalar measure of CAM utilisation. Certain items, including prayer for health purposes, and chiropractic, were not indicative of general CAM use. CONCLUSIONS: The R-I-CAM-Q provides a unitary, aggregate measure of CAM utilisation that provides scope for replicable research into the determinants of CAM use. It is the first quantitative and summative measure of general CAM use, developed and tested using modern psychometric methods