Do-it-yourself shuffling and the number of runs under randomness

A common class of problem in statistical science is estimating, as a benchmark, the probability of some event under randomness. For example, in a sequence of events in which several outcomes are possible and the length of the sequence and number of outcomes of each type known, the number of runs gives an indication of whether the outcomes are random, clustered, or alternating. This note explains and illustrates a simple method of random shuffling that is often useful. We show how the conditional probability distribution of the number of runs may be derived easily in Stata, thus yielding p-values for testing the null hypothesis that the type of outcome is random. We also compare our direct approach with that using the simulate command. Copyright 2003 by StataCorp LP.alternation, categorical data, clustering, conditional distribution, forvalues, p-value, permutation, run, sequence, simulate, simulation

The role, remit and training needs of Dementia Champions : Results from an online survey

Background: Dementia Champions play a critical role in implementing the goals of the National Dementia Strategy. Whilst there is no common definition of what a Dementia Champion is, their role is often to act as change agents in improving the experience, care, treatment and outcomes for people with dementia, their families and carers. This can be in general hospitals, community and long term care settings and at the interface between hospital and community services. Professionals and clinicians across Health and Social Care have taken up the role of Dementia Champion in addition to their existing responsibilities. Aim: The first part of the Project was completed in 2014. In its second phase the Project focused on exploring how Dementia Champions perceived their role, its remit, and which training they thought they would need in order to meet the needs of people living with dementia and to co-ordinate their care in various clinical contexts. Methods: An online survey was conducted. Findings: Most perceived dementia awareness training as useful, but limited. Areas for further development were context specific skills training, education programmes that were formally recognised, and clarification around the expectations of the role. Conclusion: Expectations of ‘champion roles’ in dementia need to be re-visited, specifically in relation to the remit of the role and the level of education, preparation and support required for DCs to become change agents in dementia care.Final Published versio

HBSC England National Report: Health Behaviour in School-aged Children (HBSC) : World Health Organization Collaborative Cross National Study

Findings from the 2014 HBSC study for Englan

Modified dietary fat intake for treatment of gallstone disease

Madden AM, Trivedi D, Smeeton NC, Culkin A., 'Modified dietary fat intake for treatment of gallstone disease', Cochrane Database of Systematic Reviews 2017, Issue 3. Art. No.: CD012608, DOI: 10.1002/14651858.CD012608. Copyright © 2017 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.Protocol: To assess the benefits and harms of modifying dietary fat intake in the treatment of gallstone disease.Peer reviewedFinal Published versio

Modified dietary fat intake for treatment of gallstone disease (Protocol)

© 2017 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.This is a protocol for a Cochrane Review (Intervention). To assess the benefits and harms of modifying dietary fat intake in the treatment of gallstone disease.Peer reviewe

Assessing prevalence, knowledge and use of cognitive enhancers among university students in the United Arab Emirates: A quantitative study

BackgroundCognitive enhancers (CE) are often used to improve memory, alertness and cognitive capacity. These products are commercially and pharmaceutically available. Due to high academic pressure, university students are at risk of CE misuse. However, data regarding this issue are limited, especially in the United Arab Emirates (UAE).AimsTo assess the prevalence of CE intake; evaluate students’ knowledge of these substances; and identify student characteristics associated with CE usage.MethodA cross sectional study based on a validated online survey that was distributed using university-licensed software (Qualtrics) as a direct web link via email and social media to all Medical, Pharmacy, Dentistry, Nursing and Engineering students enrolled in six UAE universities. Associations between student characteristics and CE use were investigated using the chi-squared test and multiple logistic regression. Reasons for CE use, temporal patterns of use, details regarding purchase and types of CE used were compared by gender.ResultsOne quarter of students had used CEs. There was a clear difference between users and non-users in terms of gender (p<0.001). CE users were disproportionately represented by students from either UAE or other Arab countries (p<0.001), and by students of Medicine, followed by Pharmacy, Dentistry, and Engineering (p<0.001). CE use increased with year of study, reaching the highest level in the fourth year (p<0.001), which for most programmes is the final year. Modafinil was self-administered, especially in males, for concentration and alertness; B12 was typically taken by female students for academic performance and concentration; and high-dosage caffeine compounds were ingested to improve alertness levels. Use of the internet for both obtaining information and purchasing CEs was frequently reported. Multiple logistic regression analysis showed that gender, nationality, and year of study were associated with CE use among UAE university students.ConclusionsUniversities need to address the prevalence of CE use amongst their students by providing effective support programs

Exploring the baseline knowledge and experience of healthcare professionals in the United Kingdom on Novel Psychoactive Substances

Submitted 28 january 2020. Reviwers' comments received 11 February 2020. Accepted 26 February 2020. Published 2 March 2020.Objective: This survey aimed to explore knowledge and experience on novel psychoactive substances (NPS) of healthcare professionals (HCPs). The study also aimed to assess how HCPs would like to improve their knowledge of NPS. Methods: Seventy paper questionnaires were disseminated in 2017 within continuing education events to pharmacists, nurses and general practitioners (GPs). Additionally, 127 online surveys were completed using the Qualtrics platform by other HCPs and mental health nurses in six United Kingdom (UK) independent mental health hospitals long-stay in-patient rehabilitation services. Two educational sessions involving pharmacists and GPs were also held in late 2017 and mid-2018. Knowledge of NPS by HCPs was evaluated prior to the start of the educational events. Evaluation forms were handed out post-sessions to garner feedback, especially on areas for improvement for future sessions. Statistical analysis of data was undertaken using SPSS (V.25). Results: Most HCPs reported only 'basic' to 'intermediate' NPS knowledge. Substance misuse service staff felt more informed, were more often consulted and had greater confidence regarding NPS compared to hospital and primary care professionals. A negative association was found between the age of the HCP and knowledge of NPS. Most participants expressed a need for regular training and updates as insufficient NPS-related information is currently received. Conclusions: An improvement within the self-reported knowledge of HCPs on NPS is evident in comparison to previous studies. Continued education of HCPs on NPS is fundamental for the provision of improved harm reduction services, which can enhance overall care for NPS service users.Peer reviewedFinal Published versio

Guidance for Researchers: Feedback : Patient and Public Involvement (PPI): Feedback from Researchers to PPI Contributors

© 2018 The Author(s). This an open access work distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited

A protocol for investigation of the effects of outdoor air pollution on stroke incidence, phenotypes and survival using the South London Stroke Register.

Stroke is a major cause of death and disability. About 5.3 million people die every year from stroke worldwide with over 9 million people surviving at any one time after suffering a stroke. About 1 in 4 men and 1 in 5 women aged 45 years will suffer a stroke if they live to their 85th year. It is estimated that by 2023 there will be an absolute increase in the number of people experiencing a first ever stroke of about 30% compared with 1983. In the UK, stroke is the third commonest cause of death and the most common cause of adult physical disability and consumes 5% of the health and social services budget. Stroke is assuming strategic public health importance because of increased awareness in society, an ageing population and emerging new treatments. It is an NHS health service and research priority, being identified as a target in Our Healthier Nation and the NSF for Older People for prevention and risk factor control and in the NHS Plan as a disease requiring intermediate care planning and reduction in inequalities of care. Whilst a number of risk factors for stroke are well known (e.g. increasing age, ethnicity, socioeconomic deprivation, hypertension), the potential importance of outdoor air pollution as a modifiable risk factor is much less well recognised. This is because studies to date are inconclusive or have methodological limitations. In Sheffield, we estimated that 11% of stroke deaths may be linked to current levels of outdoor air pollution and this high figure is explained by the fact that so many people are exposed to air pollution.We plan to study the effects of outdoor air pollution on stroke using a series of epidemiological (i.e. population based) studies. The purpose of this project is: to examine if short term increases in pollution can trigger a stroke in susceptible individuals, to investigate if the occurrence of stroke is higher amongst people living in more polluted areas (which would be explained by a combination of exposure to short term increases and longer term exposure to higher pollution levels), and to see if people living in more polluted areas have reduced survival following their stroke. We will use geographical information systems, robust statistical methods and powerful grid computing facilities to link and analyse the data. The datasets we will use are the South London Stroke Register database, daily monitored pollution data from national monitoring networks and modelled pollution data for London from the Greater London Authority. The South London Stroke Register records information on all patients who suffer a stroke ("incident" cases) living within a defined area. This stroke incidence dataset offers major advantages over previous studies examining the effects of pollution on hospital admissions and mortality, as not all patients with stroke are admitted or die and there may be a delay between the onset of stroke and admission or death. In addition, it contains other useful information, particularly the type of stroke people have suffered. Air pollution is a potentially modifiable risk factor for stroke. This study will provide robust population level evidence regarding the effects of outdoor air pollution on stroke. If it confirms the link, it will suggest to policy-makers at national and international levels that targeting policy interventions at high pollution areas may be a feasible option for stroke prevention