Quantum Hall induced currents and the magnetoresistance of a quantum point contact

We report an investigation of quantum Hall induced currents by simultaneous measurements of their magnetic moment and their effect on the conductance of a quantum point contact (QPC). Features in the magnetic moment and QPC resistance are correlated at Landau-level filling factors nu=1, 2 and 4, which demonstrates the common origin of the effects. Temperature and non-linear sweep rate dependences are observed to be similar for the two effects. Furthermore, features in the noise of the induced currents, caused by breakdown of the quantum Hall effect, are observed to have clear correlations between the two measurements. In contrast, there is a distinct difference in the way that the induced currents decay with time when the sweeping field halts at integer filling factor. We attribute this difference to the fact that, while both effects are sensitive to the magnitude of the induced current, the QPC resistance is also sensitive to the proximity of the current to the QPC split-gate. Although it is clearly demonstrated that induced currents affect the electrostatics of a QPC, the reverse effect, the QPC influencing the induced current, was not observed

Cardiovascular risk models for South Asian populations: a systematic review.

OBJECTIVES: To review existing cardiovascular risk models applicable to South Asian populations. METHODS: A systematic review of the literature using a combination of search terms for "South Asian", "cardiovascular", "risk"/"score" and existing risk models for inclusion. South Asian was defined as those residing in or with ancestry belonging to the Indian subcontinent. RESULTS: The literature search including MEDLINE and EMBASE identified 7560 papers. After full-text review, 4 papers met the inclusion criteria. Only 1 reported formal measures of model performance. In that study, both a modified Framingham model and QRISK2 showed similar good discrimination with AUROCs of 0.73-0.77 with calibration also reasonable in men (0.71-0.93) but poor in women (0.43-0.52). CONCLUSIONS: Considering the number of South Asians and prevalence of cardiovascular disease, very few studies have reported performance of risk scores in South Asian populations. Furthermore, it was difficult to make comparisons, as many did not provide measures of discrimination, accuracy and calibration. There is a need for further research to evaluate risk models in South Asians, and ideally derive and validate cardiovascular risk models within South Asian populations.JUS is supported by a National Institute of Health Research (NIHR) Clinical Lectureship.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s00038-015-0733-

Fidelity of the delivery of NHS Health Checks in General Practice

Aim To assess the fidelity of delivery of NHS Health Checks in general practice. Design and Setting Fidelity assessment of video/audio recordings of NHS Health Check consultations conducted in four GP practices across the East of England. Method A secondary analysis of 38 NHS Health Check consultations video or audio recorded as part of a pilot study of introducing discussions surrounding cancer risk into NHS Health Checks. Using a checklist based on the NHS Health Check Best Practice Guidance, fidelity of delivery was assessed as the proportion of key elements completed during the consultations. Results The mean number of elements of the NHS Health Check completed across all consultations was 14.5/18 (80.3%), with a range of 10-17 (55.6-94.4%). The mean fidelity for risk assessment, risk communication and risk management sections was 8.7/10 (86.8%), 4.1/5 (81.6%) and 1.7/3 (56.1%) respectively. Elements with the lowest fidelity were ethnicity assessment (31.6%), family history of cardiovascular disease assessment (65.8%), AUDIT-C communication (34.2%) and dementia risk management (15.8%). Conclusion Although fidelity of delivery was high overall, important elements of the NHS Health Check were being regularly omitted. Opportunities for behaviour change, particularly relating to alcohol consumption and dementia risk management, may be being missed.This study was funded by a Cancer Research UK Prevention Fellowship (C55650/A21464)

Behavioural Challenges Associated With Risk-Adapted Cancer Screening.

Cancer screening programmes have a major role in reducing cancer incidence and mortality. Traditional internationally-adopted protocols have been to invite all 'eligible individuals' for the same test at the same frequency. However, as highlighted in Cancer Research UK's 2020 strategic vision, there are opportunities to increase effectiveness and cost-effectiveness, and reduce harms of screening programmes, by making recommendations on the basis of personalised estimates of risk. In some respects, this extends current approaches of providing more intensive levels of care outside screening programmes to individuals at very high risk due to their family history or underlying conditions. However, risk-adapted colorectal cancer screening raises a wide range of questions, not only about how best to change existing programmes but also about the psychological and behavioural effects that these changes might have. Previous studies in other settings provide some important information but remain to be tested and explored further in the context of colorectal screening. Conducting behavioural science research in parallel to clinical research will ensure that risk-adapted screening is understood and accepted by the population that it aims to serve.Dr Usher Smith is funded by a NIHR Advanced Fellowship NIHR30086

Behavioural Challenges Associated With Risk-Adapted Cancer Screening

Cancer screening programmes have a major role in reducing cancer incidence and mortality. Traditional internationally-adopted protocols have been to invite all 'eligible individuals' for the same test at the same frequency. However, as highlighted in Cancer Research UK's 2020 strategic vision, there are opportunities to increase effectiveness and cost-effectiveness, and reduce harms of screening programmes, by making recommendations on the basis of personalised estimates of risk. In some respects, this extends current approaches of providing more intensive levels of care outside screening programmes to individuals at very high risk due to their family history or underlying conditions. However, risk-adapted colorectal cancer screening raises a wide range of questions, not only about how best to change existing programmes but also about the psychological and behavioural effects that these changes might have. Previous studies in other settings provide some important information but remain to be tested and explored further in the context of colorectal screening. Conducting behavioural science research in parallel to clinical research will ensure that risk-adapted screening is understood and accepted by the population that it aims to serve

The associations between the response efficacy and objective and subjective change in physical activity and diet in the Information and Risk Modification trial.

OBJECTIVES: Many health promotion campaigns and interventions focussing on improving health-related behaviours have been based on targeting response efficacy. This is based on the assumption that response efficacy is an important modifiable determinant of behaviour change. This study aimed to quantify the association between response efficacy and objective and subjective measures of physical activity and diet. STUDY DESIGN: Prospective cohort analysis of data from a randomised controlled trial. METHODS: A total of 953 participants were assessed for response efficacy at baseline and 12 weeks following randomisation to interventions to increase physical activity and improve diet. Subjective measures were collected via a self-report questionnaire that included two questions used to derive the Cambridge Index of physical activity and questions about daily or weekly fruit and vegetable, whole grain, meat and fish intake, based on the dietary guidelines to lower cardiovascular risk. Objective measures were quantified using accelerometers and plasma carotenoids. RESULTS: The mean change in response efficacy for physical activity was +0.5 (standard deviation [SD] 2.0) and for diet was +0.5 (SD 2.1).There were no clinically or statistically significant associations between baseline or change in response efficacy and objective and subjective measures of physical activity or objective measures of diet. There was a small statistically significant association between baseline response efficacy and change in self-reported wholegrain consumption, but this is unlikely to be clinically significant. CONCLUSIONS: Response efficacy is not a fundamental determinant of diet and physical activity and should not be the main focus of interventions targeting these behaviours

Variation between countries in the frequency of diabetic ketoacidosis at first presentation of type 1 diabetes in children: a systematic review.

AIMS/HYPOTHESIS: Type 1 diabetes is the most frequent endocrine disease in children, with 65,000 children diagnosed worldwide every year. Up to 80% of these children present with diabetic ketoacidosis (DKA), which is associated with both short-term risks and long-term consequences. This study aimed to characterise the worldwide variation in presentation of type 1 diabetes to inform future interventions to reduce this excess morbidity and mortality. METHODS: This was a systematic review of studies indexed on PubMed, EMBASE, Web of Science, Scopus or CINAHL before March 2011 that included unselected groups of children presenting with new-onset type 1 diabetes, reported the proportion presenting with DKA and used a definition of DKA based on measurement of pH or bicarbonate. RESULTS: Sixty-five studies of cohorts comprising over 29,000 children in 31 countries were included. The frequency of DKA at diagnosis ranged from 12.8% to 80%, with highest frequencies in the United Arab Emirates, Saudi Arabia and Romania, and the lowest in Sweden, the Slovak Republic and Canada. Multivariable modelling showed the frequency of DKA was inversely associated with gross domestic product, latitude and background incidence of type 1 diabetes. CONCLUSIONS/INTERPRETATION: This is the first description of the variation in frequency of DKA at presentation of type 1 diabetes in children across countries. It demonstrates large variations that may, at least in part, be explained by different levels of disease awareness and healthcare provision and suggests ways to decrease the excess morbidity and mortality associated with DKA at diagnosis

Offering statins to a population attending health checks with a 10-year cardiovascular disease risk between 10% and 20.

BACKGROUND: In 2014 the UK National Institute for Health and Care Excellence recommended reducing the threshold for offering statin therapy to patients from a 10-year modelled risk of cardiovascular disease (CVD) of 20% to 10%. AIM: To describe the response of patients in UK primary care with a CVD risk between 10% and 20% to an invitation to attend a consultation to discuss statins. DESIGN AND SETTING: Review of electronic medical records at one GP practice in the East of England. METHOD: We invited all patients who had attended an NHS Health Check at the practice, had a QRisk(®) score between 10% and 20%, and were not prescribed statins to attend designated clinics in the practice to discuss starting statins. We reviewed the medical records to identify those who had attended the clinics and those who had chosen to start a statin. RESULTS: Of 410 patients invited, 100 (24.4%) patients attended the designated clinics and 45 (11%) chose to start a statin. Those who chose to start a statin were older and with a higher QRisk(®) than those who did not. Among those who attended, individuals who started a statin had a higher QRisk(®) than those who did not and were more likely to be current or ex-smokers. CONCLUSIONS: The proportion choosing to start a statin was substantially lower than previously estimated. Large population-based studies with long-term follow-up are needed to assess the impact on health and workload of this change in guidance.JU-S is funded by a National Institute of Health Research Clinical Lectureship. The views expressed in this publication are those of the authors and not necessarily those of the NHS, the National Institute for Health Research, or the Department of Health.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1111/ijcp.1274

The spectrum effect in tests for risk prediction, screening, and diagnosis.

The spectrum effect describes the variation between settings in performance of tests used to predict, screen for, and diagnose disease. In particular, the predictive use of a test may be different when it is applied in a general population rather than in the study sample in which it was first developed. This article discusses the impact of the spectrum effect on measures of test performance, and its implications for the development, evaluation, application, and implementation of such tests.JUS is supported by a National Institute of Health Research (NIHR) Clinical Lectureship. The views expressed in this publication are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. SJS is supported by the Medical Research Council www.mrc.ac.uk [Unit Programme number MC_UU_12015/1].This is the final version of the article. It first appeared from the BMJ Group via https://doi.org/10.1136/bmj.i313

Working with prisoners who self-harm: a qualitative study on stress, denial of weakness, and encouraging resilience in a sample of correctional staff

Background: Rates of self‐harm are high among prisoners. Most research focuses on the vulnerable prisoner, and there is little on the impact of these behaviours on staff. Aims: To investigate staff perceptions of self‐harming behaviours by prisoners, including their views on its causes, manifestation, prevention in institutions, and impact on them. Methods: Semi-structured interviews were conducted with 20 administrative and 21 therapeutic prison staff who are responsible in various ways for prisoners who self‐harm. Their narratives were explored using interpretative phenomenological analysis. Results: Despite prison staff being experienced with prisoners' self‐harming behaviours, including severe acts of self‐harm, they were apt to reject any negative impact on their own mental health or well‐being. This denial of negative impact was accompanied by perceptions of the inmate's actions being manipulative and attention seeking. Prison staff also perceived institutional responses to self‐harming behaviours by prisoners as being mixed, ambiguous, or showing preference for relying on existing suicide protocols rather than task‐specific guidance. Conclusions: Although staff gave explanations of prisoner self‐harm in terms of “manipulative behaviour”, prisoners' self‐harm is, in fact, complex, challenging, and often severe. This staff perception may reflect denial of impact of often distressing behaviours on them personally and their own coping mechanisms. This could be feeding in to a perceived lack of clear and effective institutional responses to the self‐harm, so further research is needed to determine how staff could broaden their views, and respond more effectively to prisoners. Psychologically informed group work and/or reflective practice are among the candidates for such help for staff