A review of the Cochrane COVID-19 Study Register reveals inconsistency in the choice and measurement of SARS-CoV-2 infection outcomes in prevention trials

Background: Multiple studies are evaluating how to prevent SARS-CoV-2 infection. Interventions are wide ranging and include vaccines, prophylactic drugs, public health safety measures, and behavioural interventions. Heterogeneity in the outcomes measured and reported is leading to research waste and inefficiency, slowing worldwide identification and implementation of effective methods to prevent infection. A core outcome set (COS) for studies of interventions to prevent SARS-CoV-2 infection has recently been developed, identifying infection as a critical outcome to measure. This paper examines how SARS-CoV-2 infection outcomes are measured in registered COVID-19 prevention trials and considers how this can be improved. Methods: We searched the Cochrane COVID-19 Study Register to identify and review SARS-CoV-2 infection outcomes in prevention trials, including the rationale for choice of outcome measurement. We included phase 3 and 4 trials of COVID-19 prevention interventions. Early phase trials and studies relating to the transmission, treatment or management of COVID-19 were excluded. Results: We identified 430 entries in the register, of which 199 unique prevention trials were included across eight settings and 12 intervention types. Fifteen (8%) trials did not include any SARS-CoV-2 infection outcomes. The remaining 184 (92%) studies included a total of 268 SARS-CoV-2 infection outcomes, of which 32 (17%) did not specify how infection would be measured. Testing (i.e. formal diagnostic test) as a standalone method for determining infection was used in 57 (31%) trials, whereas defining infection by symptoms alone was used in 16 (9%) trials. All other trials (n=79, 43%) included multiple infection outcomes, defined in different ways. Discussion: There is considerable variation in how SARS-CoV-2 infection is measured within and across different interventions and settings. Furthermore, few studies report the rationale for outcome selection and measurement. Better transparency and standardisation of SARS-CoV-2 infection measurement is needed for the findings from prevention trials to inform decision-making.</ns3:p

Interpreting Tuberculin Skin Tests in a Population With a High Prevalence of HIV, Tuberculosis, and Nonspecific Tuberculin Sensitivity

Understanding the epidemiology and clinical course of tuberculosis is hampered by the absence of a perfect test for latent tuberculosis infection. The tuberculin skin test (TST) is widely used but suffers poor specificity in those receiving the bacille Calmette-Guérin vaccine and poor sensitivity in individuals with human immunodeficiency virus (HIV) infections. TST responses for a target population in Harare, Zimbabwe (HIV prevalence, 21%), recruited in 2005–2006, were interpreted by using a separate calibration population in Harare, for which interferon-gamma release assays (enzyme-linked immunosorbent spot (ELISpot)) results were also known. Statistical fitting of the responses in the calibration population allowed computation of the probability that an individual in the target population with a given TST and HIV result would have tested ELISpot positive. From this, estimates of the prevalence of tuberculosis infection, and optimal TST cutpoints to minimize misdiagnosis, were computed for different assumptions about ELISpot performance. Different assumptions about the sensitivity and specificity of ELISpot gave a 40%–57% prevalence of tuberculosis infection in the target population (including HIV-infected individuals) and optimal TST cutpoints typically in the 10 mm–20 mm range. However, the optimal cutpoint for HIV-infected individuals was consistently 0 mm. This calibration method may provide a valuable tool for interpreting TST results in other populations

Study protocol: differential effects of diet and physical activity based interventions in pregnancy on maternal and fetal outcomes--individual patient data (IPD) meta-analysis and health economic evaluation.

© 2014 Ruifrok et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.BACKGROUND: Pregnant women who gain excess weight are at risk of complications during pregnancy and in the long term. Interventions based on diet and physical activity minimise gestational weight gain with varied effect on clinical outcomes. The effect of interventions on varied groups of women based on body mass index, age, ethnicity, socioeconomic status, parity, and underlying medical conditions is not clear. Our individual patient data (IPD) meta-analysis of randomised trials will assess the differential effect of diet- and physical activity-based interventions on maternal weight gain and pregnancy outcomes in clinically relevant subgroups of women. METHODS/DESIGN: Randomised trials on diet and physical activity in pregnancy will be identified by searching the following databases: MEDLINE, EMBASE, BIOSIS, LILACS, Pascal, Science Citation Index, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Database of Abstracts of Reviews of Effects, and Health Technology Assessment Database. Primary researchers of the identified trials are invited to join the International Weight Management in Pregnancy Collaborative Network and share their individual patient data. We will reanalyse each study separately and confirm the findings with the original authors. Then, for each intervention type and outcome, we will perform as appropriate either a one-step or a two-step IPD meta-analysis to obtain summary estimates of effects and 95% confidence intervals, for all women combined and for each subgroup of interest. The primary outcomes are gestational weight gain and composite adverse maternal and fetal outcomes. The difference in effects between subgroups will be estimated and between-study heterogeneity suitably quantified and explored. The potential for publication bias and availability bias in the IPD obtained will be investigated. We will conduct a model-based economic evaluation to assess the cost effectiveness of the interventions to manage weight gain in pregnancy and undertake a value of information analysis to inform future research. SYSTEMATIC REVIEW REGISTRATION: PROSPERO 2013: CRD42013003804.This study was funded by the National Institute for Health Research (NIHR) HTA (Health Technology Assessment) UK programme 12/01

Maternal obesity support services: a qualitative study of the perspectives of women and midwives

Background - Twenty percent of pregnant women in the UK are obese (BMI ≥ 30 kg/m2), reflecting the growing public health challenge of obesity in the 21st century. Obesity increases the risk of adverse outcomes during pregnancy and birth and has significant cost implications for maternity services. Gestational weight management strategies are a high priority; however the evidence for effective, feasible and acceptable weight control interventions is limited and inconclusive. This qualitative study explored the experiences and perceptions of pregnant women and midwives regarding existing support for weight management in pregnancy and their ideas for service development. Methods - A purposive sample of 6 women and 7 midwives from Doncaster, UK, participated in two separate focus groups. Transcripts were analysed thematically. Results - Two overarching themes were identified, 'Explanations for obesity and weight management' and 'Best care for pregnant women'. 'Explanations' included a lack of knowledge about weight, diet and exercise during pregnancy; self-talk messages which excused overeating; difficulties maintaining motivation for a healthy lifestyle; the importance of social support; stigmatisation; and sensitivity surrounding communication about obesity between midwives and their clients. 'Best care' suggested that weight management required care which was consistent and continuous, supportive and non-judgemental, and which created opportunities for interaction and mutual support between obese pregnant women. Conclusions - Women need unambiguous advice regarding healthy lifestyles, diet and exercise in pregnancy to address a lack of knowledge and a tendency towards unhelpful self-talk messages. Midwives expressed difficulties in communicating with their clients about their weight, given awareness that obesity is a sensitive and potentially stigmatising issue. This indicates more could be done to educate and support them in their work with obese pregnant women. Motivation and social support were strong explanatory themes for obesity and weight management, suggesting that interventions should focus on motivational strategies and social support facilitation

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Erratum to: Study protocol: differential effects of diet and physical activity based interventions in pregnancy on maternal and fetal outcomes: individual patient data (IPD) meta-analysis and health economic evaluation.

Erratum to: Study protocol: differential effects of diet and physical activity based interventions in pregnancy on maternal and fetal outcomes: individual patient data (IPD) meta-analysis and health economic evaluatio

Одноколейные тракторно-ледяные дороги: учебное пособие для лесотехнических вузов

Книга содержит описание конструкций однополозных тракторных саней, расчет основных деталей саней, краткие технические условия проектирования одноколейных тракторно-ледяных дорог, правила постройки и эксплуатации ледяных дорог и основы организации тракторного хозяйства на базе одноколейных ледяных дорог. Книга предназначена в качестве учебного пособия для лесотехнических вузов, но может также служить практическим пособием и для высшего технического персонала лесозаготовительных предприятий Наркомлеса СССР.0|7|Предисловие [c. 7]0|8|Введение [c. 8]0|11|Возникновение и развитие конструкции однополозных саней [c. 11]1|11|Первые опыты [c. 11]1|12|Принцип работы одноколейной ледяной дороги и теоретические основания проектирования однополозных саней [c. 12]1|17|Конструкция первых однополозных саней [c. 17]1|17|Однополозные сани Востокостальлеса [c. 17]1|19|Одкополозные сани ЦНИИМЭ, модель Б [c. 19]1|21|Однополозные сани на базе поковок тракторных двухполозных саней модели Д [c. 21]1|22|Однополозные сани Я. И. Гинзбурга модели 1939 г. [c. 22]1|33|Однополозные сани ГЗЯ-2 [c. 33]1|39|Варианты соединения коника с полозом [c. 39]1|39|Модернизированные однополозные сани на базе поковок саней модели Свердлеса и Востокостальлеса [c. 39]1|44|Бескониковые однополозные сани конструкции СибНИИЛХЭ [c. 44]1|46|Буферно-прицепные устройства трактора конструкции УЛТИ, Сотринского мехлесопункта и Стройлеспроекта [c. 46]1|48|Автоматическая сцепка тракторных саней [c. 48]1|49|Рама для перевозки коротья на однополозных санях [c. 49]1|51|Расчет саней [c. 51]1|51|Расчет полоза [c. 51]1|58|О форме подрезов [c. 58]0|61|Постройка одноколейных ледяных дорог [c. 61]1|61|Условия применения, сырьевая база и порядок оформления строительства [c. 61]1|62|Технические условия проектирования одноколейных ледяных дорог [c. 62]1|72|Изыскания трасс одноколейных ледяных дорог [c. 72]1|73|Строительные работы на одноколейных ледяных дорогах [c. 73]1|85|Дорожные орудия для строительства одноколейных ледяных дорог [c. 85]1|91|Цистерны для поливки ледяной дороги [c. 91]1|91|Насосные станции [c. 91]0|95|Эксплуатация ледяных дорог [c. 95]1|95|Техническая характеристика тяговых машин [c. 95]1|107|Эксплуатация газогенераторных тракторов на лесовывозке по ледяным дорогам [c. 107]1|115|Правила вождения поездов [c. 115]1|117|Формирование состава и маневры [c. 117]1|117|Содержание и ремонт пути ледяной дороги [c. 117]1|119|Техника безопасности при вывозке леса по тракторным ледяным дорогам [c. 119]1|121|Основные правила по технике безопасности для тракторного лесотранспорта [c. 121]0|123|Приложения [c. 123]1|123|Детали однополозных саней ГЗЯ-1 [c. 123]1|136|Детали модернизированных однополозных саней на базе поковок саней Свердллеса [c. 136]1|141|Краткая техническая характеристика гусеничных тракторов Челябинского тракторного завода [c. 141]0|143|Оглавление [c. 143