On the p,qp,q-binomial distribution and the Ising model

A completely new approach to the Ising model in 1 to 5 dimensions is developed. We employ $p,q$-binomial coefficients, a generalisation of the binomial coefficients, to describe the magnetisation distributions of the Ising model. For the complete graph this distribution corresponds exactly to the limit case $p=q$. We take our investigation to the simple $d$-dimensional lattices for $d=1,2,3,4,5$ and fit $p,q$-binomial distributions to our data, some of which are exact but most are sampled. For $d=1$ and $d=5$ the magnetisation distributions are remarkably well-fitted by $p,q$-binomial distributions. For $d=4$ we are only slightly less successful, while for $d=2,3$ we see some deviations (with exceptions!) between the $p,q$-binomial and the Ising distribution. We begin the paper by giving results on the behaviour of the $p,q$-distribution and its moment growth exponents given a certain parameterization of $p,q$. Since the moment exponents are known for the Ising model (or at least approximately for $d=3$) we can predict how $p,q$ should behave and compare this to our measured $p,q$. The results speak in favour of the $p,q$-binomial distribution's correctness regarding their general behaviour in comparison to the Ising model. The full extent to which they correctly model the Ising distribution is not settled though.Comment: 51 pages, 23 figures, submitted to PRB on Oct 23 200

Adiposity has differing associations with incident coronary heart disease and mortality in the Scottish population: cross-sectional surveys with follow-up

Objective: Investigation of the association of excess adiposity with three different outcomes: all-cause mortality, coronary heart disease (CHD) mortality and incident CHD. Design: Cross-sectional surveys linked to hospital admissions and death records. Subjects: 19 329 adults (aged 18–86 years) from a representative sample of the Scottish population. Measurements: Gender-stratified Cox proportional hazards models were used to estimate hazard ratios (HRs) for all-cause mortality, CHD mortality and incident CHD. Separate models incorporating the anthropometric measurements body mass index (BMI), waist circumference (WC) or waist–hip ratio (WHR) were created adjusted for age, year of survey, smoking status and alcohol consumption. Results: For both genders, BMI-defined obesity (greater than or equal to30 kg m−2) was not associated with either an increased risk of all-cause mortality or CHD mortality. However, there was an increased risk of incident CHD among the obese men (hazard ratio (HR)=1.78; 95% confidence interval=1.37–2.31) and obese women (HR=1.93; 95% confidence interval=1.44–2.59). There was a similar pattern for WC with regard to the three outcomes; for incident CHD, the HR=1.70 (1.35–2.14) for men and 1.71 (1.28–2.29) for women in the highest WC category (men greater than or equal to102 cm, women greater than or equal to88 cm), synonymous with abdominal obesity. For men, the highest category of WHR (greater than or equal to1.0) was associated with an increased risk of all-cause mortality (1.29; 1.04–1.60) and incident CHD (1.55; 1.19–2.01). Among women with a high WHR (greater than or equal to0.85) there was an increased risk of all outcomes: all-cause mortality (1.56; 1.26–1.94), CHD mortality (2.49; 1.36–4.56) and incident CHD (1.76; 1.31–2.38). Conclusions: In this study excess adiposity was associated with an increased risk of incident CHD but not necessarily death. One possibility is that modern medical intervention has contributed to improved survival of first CHD events. The future health burden of increased obesity levels may manifest as an increase in the prevalence of individuals living with CHD and its consequences

Randomised controlled trial of a home-based physical activity intervention in breast cancer survivors

Background: To improve adherence to physical activity (PA), behavioural support in the form of behavioural change counselling may be necessary. However, limited evidence of the effectiveness of home-based PA combined with counselling in breast cancer patients exists. The aim of this current randomised controlled trial with a parallel group design was to evaluate the effectiveness of a home-based PA intervention on PA levels, anthropometric measures, health-related quality of life (HRQoL), and blood biomarkers in breast cancer survivors. Methods: Eighty post-adjuvant therapy invasive breast cancer patients (age = 53.6 ± 9.4 years; height = 161.2 ± 6.8 cm; mass = 68.7 ± 10.5 kg) were randomly allocated to a 6-month home-based PA intervention or usual care. The intervention group received face-to-face and telephone PA counselling aimed at encouraging the achievement of current recommended PA guidelines. All patients were evaluated for our primary outcome, PA (International PA Questionnaire) and secondary outcomes, mass, BMI, body fat %, HRQoL (Functional assessment of Cancer Therapy-Breast), insulin resistance, triglycerides (TG) and total (TC), high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C) cholesterol were assessed at baseline and at 6-months. Results: On the basis of linear mixed-model analyses adjusted for baseline values performed on 40 patients in each group, total, leisure and vigorous PA significantly increased from baseline to post-intervention in the intervention compared to usual care (between-group differences, 578.5 MET-min∙wk−1, p = .024, 382.2 MET-min∙wk−1, p = .010, and 264.1 MET-min∙wk−1, p = .007, respectively). Both body mass and BMI decreased significantly in the intervention compared to usual care (between-group differences, −1.6 kg, p = .040, and −.6 kg/m2, p = .020, respectively). Of the HRQoL variables, FACT-Breast, Trial Outcome Index, functional wellbeing, and breast cancer subscale improved significantly in the PA group compared to the usual care group (between-group differences, 5.1, p= .024; 5.6, p = .001; 1.9 p = .025; and 2.8, p=.007, respectively). Finally, TC and LDL-C was significantly reduced in the PA group compared to the usual care group (between-group differences, −.38 mmol∙L−1, p=.001; and −.3 mmol∙L−1, p=.023, respectively). Conclusions: We found that home-based PA resulted in significant albeit small to moderate improvements in selfreported PA, mass, BMI, breast cancer specific HRQoL, and TC and LDL-C compared with usual care

Has Motivational Interviewing fallen into its own Premature Focus Trap?

Since the initial conception of the behaviour change method Motivational Interviewing, there has been a shift evident in epistemological, methodological and practical applications, from an inductive, process and practitioner-focussed approach to that which is more deductive, research-outcome, and confirmatory-focussed. This paper highlights the conceptual and practical problems of adopting this approach, including the consequences of assessing the what (deductive outcome-focussed) at the expense of the how (inductively process-focussed). We encourage a return to an inductive, practitioner and client-focussed MI approach and propose the use of Computer Assisted Qualitative Data Analysis Systems such as NVivo in research initiatives to support this aim

Marital status and occupation in relation to short-term case fatality after a first coronary event - a population based cohort

<p>Abstract</p> <p>Background</p> <p>Although marital status and low occupation level has been associated with mortality, the relationship with case fatality rates (CFR) after a coronary event (CE) is unclear. This study explored whether incidence of CE and short-term CFR differ between groups defined in terms of marital status and occupation, and if this could be explained by biological and life-style risk factors.</p> <p>Methods</p> <p>Population-based cohort study of 33,224 subjects (67% men), aged 27 to 61 years, without history of myocardial infarction, who were enrolled between 1974 and 1992. Incidence of CE, and CFR (death during the first day or within 28 days after CE, including out-of-hospital deaths) was examined over a mean follow-up of 21 years.</p> <p>Results</p> <p>A total of 3,035 men (6.0 per 1000 person-years) and 507 women (2.4 per 1000) suffered a first CE during follow-up. CFR (during the 1^stday) was 29% in men and 23% in women. After risk factor adjustments, unmarried status in men, but not in women, was significantly associated with increased risk of suffering a CE [hazard ratios (HR) 1.10, 95% CI: 0.97-1.24; 1.42: 1.27-1.58 and 1.77: 1.31-2.40 for never married, divorced and widowed, respectively, compared to married]. Unmarried status, in both gender, was also related with an increased CFR (1^stday), taking potential confounders into account (odds ratio (OR) 2.14, 95% CI: 1.63-2.81; 1.91: 1.50-2.43 and 1.49: 0.77-2.89 for never married, divorced and widowed, respectively, compared to married men. Corresponding figures for women was 2.32: 0.93-5.81; 1.87: 1.04-3.36 and 2.74: 1.03-7.28. No differences in CFR (1^stday) were observed between occupational groups in neither gender.</p> <p>Conclusions</p> <p>In this population-based Swedish cohort, short-term CFR was significantly related to unmarried status in men and women. This relationship was not explained by biological-, life-style factors or occupational level.</p

Risk factors for ischaemic heart disease in a Cretan rural population: a twelve year follow-up study

<p>Abstract</p> <p>Background</p> <p>Crete has been of great epidemiological interest ever since the publication of the Seven Countries Study. In 1988 a well-defined area of rural Crete was studied, with only scarce signs of coronary heart disease (CHD) despite the unfavorable risk profile. The same population was re-examined twelve years later aiming to describe the trends of CHD risk factors over time and discuss some key points on the natural course of coronary heart disease in a rural population of Crete.</p> <p>Methods and Results</p> <p>We re-examined 200 subjects (80.7% of those still living in the area, 62.4 ± 17.0 years old). The prevalence of risk factors for CHD was high with 65.9% of men and 65.1% of women being hypertensive, 14.3% of men and 16.5% of women being diabetic, 44% of men being active smokers and more than 40% of both sexes having hyperlipidaemia. Accordingly, 77.5% of the population had a calculated Framingham Risk Score (FRS) ≥ 15%, significantly higher compared to baseline (p < 0.001). The overall occurrence rate for CHD events was calculated at 7.1 per 1000 person-years (95% confidence interval: 6.8–7.3).</p> <p>Conclusion</p> <p>The study confirms the unfavorable risk factor profile of a well defined rural population in Crete. Its actual effect on the observed incidence of coronary events in Cretans remains yet to be defined.</p

Levelling off of prevalence of obesity in the adult population of Sweden between 2000/01 and 2004/05

<p>Abstract</p> <p>Background</p> <p>The escalating global epidemic of obesity is of worldwide concern because of its association with several chronic diseases and premature mortality. Some subgroups seem to be more affected than others. The aim of this study was to examine whether the mean BMI (adjusted for age) and the prevalence of obesity (adjusted for all the explanatory variables) changed between 2000/01 and 2004/05 in different subgroups of the Swedish population.</p> <p>Methods</p> <p>This study compared two cross-sectional, nationwide random samples of persons aged 16 to 84 years: the first from 2000/01 (5515 men, 5838 women) and the second from 2004/05 (4681 men, 4821 women). After stratification by gender, a logistic regression model was applied to analyse possible changes in mean BMI and the prevalence of obesity between 2000/01 and 2004/05.</p> <p>Results</p> <p>Total mean BMI remained almost unchanged between 2000/01 and 2004/05 for both men and women. The prevalence of obesity increased slightly in both men and women, but not significantly (from 9.7 to 10.8% and from 9.6 to 10.2%, respectively). The prevalence of obesity in 2004/05 was especially high in some subgroups: men aged 45-54 (14.3%) or 55-64 (16.5%), women aged 65-74 (15.9%) or 75-84 (16.8%), men and women of middle educational level (15.6% and 14.4%, respectively), male former smokers (13.4%), and men from small towns or rural areas (13.1%).</p> <p>Conclusions</p> <p>Although the mean BMI and obesity were almost unchanged in the Swedish adult population between 2000/01 and 2004/05, obesity levels in Sweden remained unacceptably high, especially in certain subgroups. Primary and secondary intervention actions should strive to decrease the prevalence of obesity in Sweden.</p

Social Relationships and Mortality Risk: A Meta-analytic Review

In a meta-analysis, Julianne Holt-Lunstad and colleagues find that individuals' social relationships have as much influence on mortality risk as other well-established risk factors for mortality, such as smoking

A mixed methods process evaluation of a person-centred falls prevention program

Background RESPOND is a telephone-based falls prevention program for older people who present to a hospital emergency department (ED) with a fall. A randomised controlled trial (RCT) found RESPOND to be effective at reducing the rate of falls and fractures, compared with usual care, but not fall injuries or hospitalisations. This process evaluation aimed to determine whether RESPOND was implemented as planned, and identify implementation barriers and facilitators. Methods A mixed-methods evaluation was conducted alongside the RCT. Evaluation participants were the RESPOND intervention group (n=263) and the clinicians delivering RESPOND (n=7). Evaluation data were collected from participant recruitment and intervention records, hospital administrative records, audio-recordings of intervention sessions, and participant questionnaires. The Rochester Participatory Decision-Making scale (RPAD) was used to evaluate person-centredness (score range 0 (worst) - 9 (best)). Process factors were compared with pre-specified criteria to determine implementation fidelity. Six focus groups were held with participants (n=41), and interviews were conducted with RESPOND clinicians (n=6). Quantitative data were analysed descriptively and qualitative data thematically. Barriers and facilitators to implementation were mapped to the ‘Capability, Opportunity, Motivation – Behaviour’ (COM-B) behaviour change framework. Results RESPOND was implemented at a lower dose than the planned 10 hours over six months, with a median (IQR) of 2.9 hours (2.1, 4). The majority (76%) of participants received their first intervention session within one month of hospital discharge. Clinicians delivered the program in a person-centred manner with a median (IQR) RPAD score of 7 (6.5, 7.5) and 87% of questionnaire respondents were satisfied with the program. The reports from participants and clinicians suggested that implementation was facilitated by the use of positive and personally relevant health messages. Complex health and social issues were the main barriers to implementation. Conclusions RESPOND was person-centred and reduced falls and fractures at a substantially lower dose, using fewer resources, than anticipated. However, the low dose delivered may account for the lack of effect on falls injuries and hospitalisations. The results from this evaluation provide detailed information to guide future implementation of RESPOND of similar programs. Trial registration: This study was registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12614000336684 (27 March 2014)