• Attention should be given to multiplicity issues in systematic reviews.

    17 November 2017

    OBJECTIVE: The objective of this paper is to describe the problem of multiple comparisons in systematic reviews and to provide some guidelines on how to deal with it in practice. STUDY DESIGN AND SETTING: We describe common reasons for multiplicity in systematic reviews, and present some examples. We provide guidance on how to deal with multiplicity when it is unavoidable. RESULTS: We identified six common reasons for multiplicity in systematic reviews: multiple outcomes, multiple groups, multiple time points, multiple effect measures, subgroup analyses, and multiple looks at accumulating data. The existing methods to deal with multiplicity in single trials can not always be applied in systematic reviews. CONCLUSION: There is no simple and completely satisfactory solution to the problem of multiple comparisons in systematic reviews. More research is required to develop multiple comparison procedures for use in systematic reviews. Authors and consumers of systematic reviews should give serious attention to multiplicity in systematic reviews when presenting, interpreting and using the results of these reports.

  • International activity in the Cochrane Collaboration with particular reference to India.

    17 November 2017

    The Cochrane Collaboration is the world's largest organization dedicated to preparing, maintaining and promoting the accessibility of systematic reviews of the effects of healthcare interventions. It is an international organization with participants in more than 100 countries. Since the year 2000, a periodic audit has been done to count the number of active members in Cochrane Review Groups, categorized by the countries in which these people are based. At the beginning of 2007, there were more than 15 800 people involved, an increase from about 5500 in 2000. The South Asian Cochrane Network was formed in 2005 to raise awareness about the Cochrane Collaboration and evidence-based practice in South Asia, support review authors and contributors from countries within the region, promote access to The Cochrane Library and advocate high quality research in South Asia. The growth of activity in India has been dramatic, particularly authors of Cochrane reviews and protocols--from just 19 (with 11 authors) in 2000 to 126 (with 78 authors) in 2007. Increasing the uptake of relevant and reliable evidence in healthcare decisions in India and the South Asian region forms the core of the network's strategic plan. The continued growth of contributors from India and South Asia will help ensure that decisions regarding healthcare in the region are informed by reliable and relevant evidence.

  • Supervisor assessment of clinical and professional competence of medical trainees: a reliability study using workplace data and a focused analytical literature review.

    17 November 2017

    Even though rater-based judgements of clinical competence are widely used, they are context sensitive and vary between individuals and institutions. To deal adequately with rater-judgement unreliability, evaluating the reliability of workplace rater-based assessments in the local context is essential. Using such an approach, the primary intention of this study was to identify the trainee score variation around supervisor ratings, identify sampling number needs of workplace assessments for certification of competence and position the findings within the known literature. This reliability study of workplace-based supervisors' assessments of trainees has a rater-nested-within-trainee design. Score variation attributable to the trainee for each competency item assessed (variance component) were estimated by the minimum-norm quadratic unbiased estimator. Score variance was used to estimate the number needed for a reliability value of 0.80. The trainee score variance for each of 14 competency items varied between 2.3% for emergency skills to 35.6% for communication skills, with an average for all competency items of 20.3%; the "Overall rating" competency item trainee variance was 28.8%. These variance components translated into 169, 7, 17 and 28 assessments needed for a reliability of 0.80, respectively. Most variation in assessment scores was due to measurement error, ranging from 97.7% for emergency skills to 63.4% for communication skills. Similar results have been demonstrated in previously published studies. In summary, overall supervisors' workplace based assessments have poor reliability and are not suitable for use in certification processes in their current form. The marked variation in the supervisors' reliability in assessing different competencies indicates that supervisors may be able to assess some with acceptable reproducibility; in this case communication and possibly overall competence. However, any continued use of this format for assessment of trainee competencies necessitates the identification of what supervisors in different institutions can reliably assess rather than continuing to impose false expectations from unreliable assessments.

  • Systematic review of reviews of risk factors for intracranial aneurysms.

    17 November 2017

    Systematic reviews of systematic reviews identify good quality reviews of earlier studies of medical conditions. This article describes a systematic review of systematic reviews performed to investigate factors that might influence the risk of rupture of an intracranial aneurysm. It exemplifies the technique of this type of research and reports the finding of a specific study. The annual incidence of subarachnoid haemorrhage resulting from the rupture of intracranial aneurysms is estimated to be nine per 100,000. A large proportion of people who have this bleed, will die or remain dependent on the care of others for some time. Reliable knowledge about the risks of subarachnoid haemorrhage in different populations will help in planning, screening and prevention strategies and in predicting the prognosis of individual patients. If the necessary data were available in the identified reviews, an estimate for the numerical relationship between a particular characteristic and the risk of subarachnoid haemorrhage was included in this report. The identification of eligible systematic reviews relied mainly on the two major bibliographic databases of the biomedical literature: PubMed and EMBASE. These were searched in 2006, using specially designed search strategies. Approximately 2,000 records were retrieved and each of these was checked carefully against the eligibility criteria for this systematic review. These criteria required that the report be a systematic review of studies assessing the risk of subarachnoid haemorrhage in patients known to have an unruptured intracranial aneurysm or of studies that had investigated the characteristics of people who experienced a subarachnoid haemorrhage without previously being known to have an unruptured aneurysm. Reports which included more than one systematic review were eligible and each of these reviews was potentially eligible. The quality of each systematic review was assessed. In this review, 16 separate reports were identified, including a total of 46 eligible systematic reviews. These brought together research studies for 24 different risk factors. This has shown that the following factors appear to be associated with a higher risk of subarachnoid haemorrhage: being a woman, older age, posterior circulation aneurysms, larger aneurysms, previous symptoms, "non-white" ethnicity, hypertension, low body mass index, smoking and alcohol consumption of more than 150 g per week. The following factors appear to be associated with a lower risk of subarachnoid haemorrhage: high cholesterol, diabetes and use of hormone replacement therapy.

  • A systematic review and quality assessment of systematic reviews of fetal fibronectin and transvaginal length for predicting preterm birth.

    17 November 2017

    This systematic review aims to identify reviews of fetal fibronectin and transvaginal cervical length for predicting preterm birth, so that these could be appraised and the findings from good quality reviews highlighted. Reviews, rather than individual studies, are the basis for this systematic review because of the proliferation of reviews and the benefits of a single, consistent appraisal and assessment of evidence from these reviews, rather than further attempts to find and appraise the many individual studies in the literature. Potentially eligible reviews were sought primarily through searches of the electronic databases MEDLINE (1966-2005), EMBASE (1980-2005), CINHAL (1982-2005), Science Citation Index (1970-2005) and The Cochrane Library (Issue 3, 2005). Our systematic review consists of a description of the two factors that might be predictive of preterm birth and for which at least one relevant review was found. The scope and quality of the identified review(s) are described, and their conclusions and the strength of these conclusions discussed. Ten reviews were identified, of which seven were included in this systematic review of reviews. The quality of each review is assessed within the following domains; the extent of searching undertaken, description of study selection and inclusion criteria, comparability of included studies, assessment of publication bias, assessment of heterogeneity and conduct of sensitivity analyses. The reviews we identified show that cervicovaginal fetal fibronectin and transvaginal sonographic cervical length measurements are clinically useful factors in predicting preterm birth. Consideration might be given to the use of both the measurement of cervicovaginal fetal fibronectin and transvaginal sonographic assessment of cervical length to identify women at increased risk of preterm birth and, potentially, to improve the outcome for these women and their babies.

  • Blood Pressure

    21 June 2016

    The Global Burden of Disease 2010 study attributed more deaths to high blood pressure than to any other risk factor. Blood pressure is a well-established risk factor for vascular disease, but important question remain about its importance in different patient groups and for different clinical outcomes.

  • Randomised Trials

    21 June 2016

  • Prospective Studies

    21 June 2016

  • Methods

    21 June 2016

  • Cardiovascular Disease

    29 July 2015

    Cardiovascular disease (CVD) includes all the diseases of the heart and circulation including coronary heart disease, angina, heart attack, congenital heart disease and stroke. Despite improvements in the prevention and treatment of CVD in recent decades, it remains the leading cause of death worldwide, particularly in developed countries.

  • Cancer

    21 June 2016

    In 2012, cancer was responsible for around 8 million deaths globally and, despite improvements in survival seen in recent decades, remains a major cause of death. The most common types of cancer in males are lung cancer, prostate cancer, colorectal cancer, and stomach cancer, and in females, the most common types are breast cancer, colorectal cancer, lung cancer, and cervical cancer.

  • Kidney Disease

    21 June 2016

    Chronic kidney disease is a significant and growing contributor to the global burden of disease. There are around 60,000 kidney transplants globally per year. There are more than half a million people worldwide with a transplant with many more people waiting for a transplant, so a priority for research is to better understand how treatment can extend the life of transplanted kidneys. People with kidney disease are also at a much higher risk of developing a number of diseases, particularly cardiovascular disease, and so more research is also needed on treatments to prevent these diseases in people with kidney disease.