Citation classics in systematic reviews and meta-analyses : who wrote the top 100 most cited articles?

Background: Systematic reviews of the literature occupy the highest position in currently proposed hierarchies of evidence. The aims of this study were to assess whether citation classics exist in published systematic review and meta-analysis (SRM), examine the characteristics of the most frequently cited SRM articles, and evaluate the contribution of different world regions. Methods: The 100 most cited SRM were identified in October 2012 using the Science Citation Index database of the Institute for Scientific Information. Data were extracted by one author. Spearman’s correlation was used to assess the association between years since publication, numbers of authors, article length, journal impact factor, and average citations per year. Results: Among the 100 citation classics, published between 1977 and 2008, the most cited article received 7308 citations and the least-cited 675 citations. The average citations per year ranged from 27.8 to 401.6. First authors from the USA produced the highest number of citation classics (n=46), followed by the UK (n=28) and Canada (n=15). The 100 articles were published in 42 journals led by the Journal of the American Medical Association (n=18), followed by the British Medical Journal (n=14) and The Lancet (n=13). There was a statistically significant positive correlation between number of authors (Spearman’s rho=0.320, p=0.001), journal impact factor (rho=0.240, p=0.016) and average citations per year. There was a statistically significant negative correlation between average citations per year and year since publication (rho = -0.636, p=0.0001). The most cited papers identified seminal contributions and originators of landmark methodological aspects of SRM and reflect major advances in the management of and predisposing factors for chronic diseases. Conclusions: Since the late 1970s, the USA, UK, and Canada have taken leadership in the production of citation classic papers. No first author from low or middle-income countries (LMIC) led one of the most cited 100 SRM

Effects of MVA85A vaccine on tuberculosis challenge in animals: systematic review

Background The existing Bacillus Calmette–Guérin (BCG) vaccination provides partial protection against tuberculosis (TB). The modified vaccinia ankara virus-expressing antigen 85A (MVA85A) aims to boost BCG immunity. We evaluated the animal evidence supporting the testing of MVA85A in humans. Methods Our protocol included in vivo preclinical studies of the MVA85A booster with BCG compared with BCG alone, followed by a TB challenge. We used standard methods for systematic review of animal studies, and summarized mortality, measures of pathology and lung bacterial load. The comprehensive literature search was to September 2014. Two independent investigators assessed eligibility and performed data extraction. We assessed study quality and pooled bacteria load using random effect meta-analysis. Findings We included eight studies in 192 animals. Three experiments were in mice, two in guinea pigs, two in macaques and one in calves. Overall, study quality was low with no randomization, baseline comparability not described and blinding not reported. For animal death (including euthanasia due to severe morbidity), studies were underpowered, and overall no benefit demonstrated. No difference was shown for lung pathology measured on an ordinal scale or bacterial load. The largest mortality trial carried out in macaques had more deaths in the MVA85A vaccine group, and was published after a trial in South Africa had started recruiting children. Conclusions This independent assessment of the animal data does not provide evidence to support efficacy of MVA85A as a BCG booster. More rigorous conduct and reporting of preclinical research are warranted, and we believe the results of studies should be publicly available before embarking on trials in humans, irrespective of the findings

Prevalence of Arthritis in Africa: A Systematic Review and Meta-Analysis

Objective In this systematic review, we estimate the prevalence of six types of arthritis in Africa; namely rheumatoid arthritis, osteoarthritis, juvenile arthritis, psoriatic arthritis, gout, and ankylosing spondylitis. Methods We comprehensively searched literature on 31 August 2014 in MEDLINE, EMBASE, Web of Science and the Cochrane Library to identify eligible studies from 1975 up to 31 July 2014. Two review authors independently selected studies, extracted data, and appraised studies. We carried out random effects meta-analysis of prevalence of arthritis and assessed heterogeneity through subgroup analyses. We performed separate analyses for population- and hospital-based studies, as well as rural and urban settings. Main Findings We included 27 cross-sectional studies (20 population-based and 7 hospital-based) from Africa reporting on the prevalence of arthritis. The majority of the studies were from South Africa (44.4%, 12/27). Rheumatoid arthritis in urban settings ranged from 0.1% in Algeria, 0.6% in the DRC, to a meta-analysis overall prevalence of 2.5% in South Africa, and in rural settings ranged from a meta-analysis overall prevalence of 0.07% in South Africa, 0.3% in Egypt, to 0.4% in Lesotho. Osteoarthritis was the most prevalent form of arthritis and in urban settings it was 55.1% in South Africa and in rural settings, all in South Africa, ranged from 29.5%, 29.7%, up to 82.7% among adults aged over 65 years. Other results include highest prevalence of 33.1% for knee osteoarthritis in rural South Africa, 0.1% for ankylosing spondylitis in rural South Africa, 4.4% for psoriatic arthritis in urban South Africa, 0.7% for gout in urban South Africa, and 0.3% for juvenile idiopathic arthritis in urban Egypt. A third of the included studies had a low risk of bias (33.3%, 9/27), 40.8% (11/27) moderate risk, and 25.9% (7/27) had a high risk of bias. Conclusions In this systematic review, we have identified the paucity of latest prevalence data on arthritis in Africa. More studies are needed to address the prevalence and the true burden of this disease in Africa

Workshop report: building biostatistics capacity in Sub-saharan Africa-taking action

To address the need for capacity development in biostatistics in the Sub-Saharan African region and to move recommendations from previous workshops into action, we brought together biostatisticians from the region to provide an opportunity to brainstorm biostatistics capacity development in Africa, how to enhance what is being done and establish collaborative links to work together. In order to move key recommendations forward working groups were established to focus on the structure and content of a MSc Biostatistics and on the development of a concept paper for an Africa Centre for Biostatistics Excellence.Pan African Medical Journal 2015; 2

The Cochrane Corner in the SAMJ: Summaries of Cochrane systematic reviews for evidence-informed practice

This editorial introduces a regular contribution from Cochrane South Africa (http://www.mrc.ac.za/cochrane/cochrane.htm) to the South African Medical Journal, which will be called the ‘Cochrane Corner’. Our contribution takes the form of technical summaries of Cochrane systematic reviews handpicked for their relevance to South Africa and the African region. Our goal is to help ensure that the high-quality evidence in Cochrane reviews reaches a wider audience.

Development of a method for the measurement of primary cilia length in 3D

BACKGROUND: Primary cilia length is an important measure of cell and tissue function. While accurate length measurements can be calculated from cells in 2D culture, measurements in tissue or 3D culture are inherently difficult due to optical distortions. This study uses a novel combination of image processing techniques to rectify optical distortions and accurately measure cilia length from 3D images. METHODS: Point spread functions and experimental resolutions were calculated from subresolution microspheres embedded in 3D agarose gels for both wide-field fluorescence and confocal laser scanning microscopes. The degree of axial smearing and spherical aberration was calculated from xy:xz diameter ratios of 3D image data sets of 4 μm microspheres that had undergone deconvolution and/or Gaussian blurring. Custom-made 18 and 50 μm fluorescent microfibers were also used as calibration objects to test the suitability of processed image sets for 3D skeletonization. Microfiber length in 2D was first measured to establish an original population mean. Fibers were then embedded in 3D agarose gels to act as ciliary models. 3D image sets of microfibers underwent deconvolution and Gaussian blurring. Length measurements within 1 standard deviation of the original 2D population mean were deemed accurate. Finally, the combined method of deconvolution, Gaussian blurring and skeletonization was compared to previously published methods using images of immunofluorescently labeled renal and chondrocyte primary cilia. RESULTS: Deconvolution significantly improved contrast and resolution but did not restore the xy:xz diameter ratio (0.80). Only the additional step of Gaussian blurring equalized xy and xz resolutions and yielded a diameter ratio of 1.02. Following image processing, skeletonization successfully estimated microfiber boundaries and allowed reliable and repeatable measurement of fiber lengths in 3D. We also found that the previously published method of calculating length from 2D maximum projection images significantly underestimated ciliary length. CONCLUSIONS: This study used commercial and public domain image processing software to rectify a long-standing problem of 3D microscopy. We have shown that a combination of deconvolution and Gaussian blurring rectifies optical distortions inherent in 3D images and allows accurate skeletonization and length measurement of microfibers and primary cilia that are bent or curved in 3D space

Evidence synthesis workshops: moving from face-to-face to online learning

Postgraduate training is moving from face-to-face workshops or courses to online learning to help increase access to knowledge, expertise and skills, and save the cost of face-to-face training. However, moving from face-to-face to online learning for many of us academics is intimidating, and appears even more difficult without the help of a team of technologists. In this paper, we describe our approach, our experiences and the lessons we learnt from converting a Primer in Systematic Reviews face-to-face workshop to a 6-week online course designed for healthcare professionals in Africa. We learnt that the team needs a balance of skills and experience, including technical know-how and content knowledge; that the learning strategies needed to achieve the learning objectives must match the content delivery. The online approach should result in both building knowledge and developing skills, and include interactive and participatory approaches. Finally, the design and delivery needs to keep in mind the limited and expensive internet access in some resource-poor settings in Africa

Analytical methods used in estimating the prevalence of HIV/AIDS from demographic and cross-sectional surveys with missing data: a systematic review.

BACKGROUND: Sero- prevalence studies often have a problem of missing data. Few studies report the proportion of missing data and even fewer describe the methods used to adjust the results for missing data. The objective of this review was to determine the analytical methods used for analysis in HIV surveys with missing data. METHODS: We searched for population, demographic and cross-sectional surveys of HIV published from January 2000 to April 2018 in Pub Med/Medline, Web of Science core collection, Latin American and Caribbean Sciences Literature, Africa-Wide Information and Scopus, and by reviewing references of included articles. All potential abstracts were imported into Covidence and abstracts screened by two independent reviewers using pre-specified criteria. Disagreements were resolved through discussion. A piloted data extraction tool was used to extract data and assess the risk of bias of the eligible studies. Data were analysed through a quantitative approach; variables were presented and summarised using figures and tables. RESULTS: A total of 3426 citations where identified, 194 duplicates removed, 3232 screened and 69 full articles were obtained. Twenty-four studies were included. The response rate for an HIV test of the included studies ranged from 32 to 96% with the major reason for the missing data being refusal to consent for an HIV test. Complete case analysis was the primary method of analysis used, multiple imputations 11(46%) was the most advanced method used, followed by the Heckman's selection model 9(38%). Single Imputation and Instrumental variables method were used in only two studies each, with 13(54%) other different methods used in several studies. Forty-two percent of the studies applied more than two methods in the analysis, with a maximum of 4 methods per study. Only 6(25%) studies conducted a sensitivity analysis, while 11(46%) studies had a significant change of estimates after adjusting for missing data. CONCLUSION: Missing data in survey studies is still a problem in disease estimation. Our review outlined a number of methods that can be used to adjust for missing data on HIV studies; however, more information and awareness are needed to allow informed choices on which method to be applied for the estimates to be more reliable and representative

Editorial: South African Guidelines Excellence (SAGE): Efficient, effective and unbiased clinical practice guideline teams

No Abstrac

Особливості планування і використання робочого часу менеджера

Introduction: Extensive research has been undertaken over the last 30 years on the methods underpinning clinical practice guidelines (CPGs), including their development, updating, reporting, tailoring for specific purposes, implementation and evaluation. This has resulted in an increasing number of terms, tools and acronyms. Over time, CPGs have shifted from opinion-based to evidence-informed, including increasingly sophisticated methodologies and implementation strategies, and thus keeping abreast of evolution in this field of research can be challenging. Methods: This article collates findings from an extensive document search, to provide a guide describing standards, methods and systems reported in the current CPG methodology and implementation literature. This guide is targeted at those working in health care quality and safety and responsible for either commissioning, researching or delivering health care. It is presented in a way that can be updated as the field expands. Conclusion: CPG development and implementation have attracted the most international interest and activity, whilst CPG updating, adopting (with or without contextualization), adapting and impact evaluation are less well addressed.Funding Agencies|South African Medical Research Council</p