Cochrane Collaboration

About: Cochrane Collaboration is a nonprofit organization based out in Oxford, United Kingdom. It is known for research contribution in the topics: Systematic review & Randomized controlled trial. The organization has 1995 authors who have published 3928 publications receiving 382695 citations.

Pregnancy outcomes after assisted human reproduction.

Abstract: Objective To review the effect of assisted human reproduction (AHR) on perinatal outcomes, to identify areas requiring further research with regard to birth outcomes and AHR, and to provide guidelines to optimize obstetrical management and counselling of prospective Canadian parents. Outcomes This document compares perinatal outcomes of different types of AHR pregnancies with each other and with those of spontaneously conceived pregnancies. Clinicians will be better informed about the adverse outcomes that have been documented in association with AHR, including obstetrical complications, adverse perinatal outcomes, multiple gestations, structural congenital abnormalities, chromosomal abnormalities, and imprinting disorders. Evidence Published literature was retrieved through searches of MEDLINE and the Cochrane Library from January 2005 to December 2012 using appropriate controlled vocabulary and key words (assisted reproduction, assisted reproductive technology, ovulation induction, intracytoplasmic sperm injection, embryo transfer, and in vitro fertilization). Results were not restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies; studies of all designs published in English from January 2005 to December 2012 were reviewed, and additional publications were identified from the bibliographies of these articles. Searches were updated on a regular basis and incorporated in the guideline to August 2013. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. Values The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1).

XPath containment for index and materialized view matching

Abstract: A method for using pre-computed information stored in auxiliary structures to speed up processing of expensive queries on hierarchical documents such as XML documents being queried using XPath. The invention defines a taxonomy of such structures such as indexes and materialized views for storing pre-computed XPath results (PXRs), determines what portion of the query can be evaluated by the structures, and computes the compensation for the results generated by the structures. The invention detects all structures applicable to the query and rewrites the query to use such structures, speeding up the performance of the queries. The invention identifies the matching structures by detecting containment mappings between XPath expressions in the query and the structure. The invention also includes a new representation for XPath expressions that is rich enough to express all features of XPath.

Systematic review and meta-analysis of the effect of portal triad clamping on outcome after hepatic resection.

Abstract: Background: The effect of portal triad clamping (PTC) on outcome after hepatic resection is uncertain. Methods: A systematic literature search was conducted to detect randomized controlled trials (RCTs) assessing the effectiveness and safety of PTC alone and of PTC with ischaemic preconditioning (IPC) of the liver. Studies on clamping of the inferior vena cava or hepatic veins were excluded. Endpoints included postoperative overall morbidity and mortality, cardiopulmonary and hepatic morbidity, blood loss, transfusion rates and alanine aminotransferase (ALT) levels. Meta-analyses were performed using a random-effects model. Results: Eight RCTs published between 1997 and 2006 containing a total of 558 patients were eligible for final analysis. The design of the identified studies varied considerably. Analyses of endpoints revealed no difference between intermittent PTC and no PTC. Meta-analyses of PTC with and without previous IPC revealed no differences, but postoperative ALT levels were significantly lower with IPC. Conclusion: On currently available evidence, the routine use of PTC does not offer any benefit in perioperative outcome after liver resection. It cannot be recommended as a standard procedure. Copyright © 2008 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

A safety review and meta-analyses of bevacizumab and ranibizumab: off-label versus goldstandard.

Abstract: Background We set out a systemic review to evaluate whether off-label bevacizumab is as safe as licensed ranibizumab, and whether bevacizumab can be justifiably offered to patients as a treatment for age-related macular degeneration with robust evidence of no differential risk.

Aerobic physical exercise for adult patients with haematological malignancies

Abstract: Background Although people with haematological malignancies have to endure long phases of therapy and immobility which is known to diminish their physical performance level, the advice to rest and avoid intensive exercises is still common practice. This recommendation is partly due to the severe anaemia and thrombocytopenia from which many patients suffer. The inability to perform activities of daily living restricts them, diminishes their quality of life and can influence medical therapy. Objectives To evaluate the efficacy, safety and feasibility of aerobic physical exercise for adults suffering from haematological malignancies. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2014, Issue 1) and MEDLINE (1950 to January 2014) as well as conference proceedings for randomised controlled trials (RCTs). Selection criteria We included RCTs comparing an aerobic physical exercise intervention, intending to improve the oxygen system, in addition to standard care with standard care only for adults suffering from haematological malignancies. We also included studies that evaluated aerobic exercise in addition to strength training. We excluded studies that investigated the effect of training programmes that were composed of yoga, tai chi chuan, qigong or similar types of exercise. We also excluded studies exploring the influence of strength training without additive aerobic exercise. Additionally, we excluded studies assessing outcomes without any clinical impact. Data collection and analysis Two review authors independently screened search results, extracted data and assessed the quality of trials. We used risk ratios (RRs) for adverse events and 100-day survival, standardised mean differences for quality of life (QoL), fatigue, and physical performance, and mean differences for anthropometric measurements. Main results Our search strategies identified 1518 potentially relevant references. Of these, we included nine RCTs involving 818 participants. The potential risk of bias in these trials is unclear, due to poor reporting. The majority of participants suffered from acute lymphoblastic leukaemia (ALL), acute myeloid leukaemia (AML), malignant lymphoma and multiple myeloma, and six trials randomised people receiving stem cell transplantation. Mostly, the exercise intervention consisted of various walking intervention programmes with different duration and intensity levels. Our primary endpoint of overall survival (OS) was not analysed in any of the included trials, but three trials reported deceased participants during the course of the study or during the first 100 days. There is no evidence for a difference between participants exercising and those in the control group (RR 0.93; 95% CI 0.59 to 1.47; P = 0.75; 3 trials, 269 participants, moderate quality of evidence). Four trials analysed the influence of exercise intervention on quality of life (QoL). Excluding one trial with serious baseline imbalances, physical exercise improves QoL (SMD 0.26; 95% CI 0.03 to 0.49; P = 0.03; 3 trials, 291 participants, low quality of evidence). This positive effect of exercise was also found in the subscales physical functioning (SMD 0.33; 95% CI 0.13 to 0.52; P = 0.0009; 4 trials, 422 participants, moderate quality of evidence) and depression (SMD 0.25; 95% CI -0.00 to 0.50; P = 0.05; 3 trials, 249 participants, low quality of evidence). However, there is no evidence for a difference between additional exercise and standard treatment for the subscale anxiety (SMD -0.18; 95% CI -0.64 to 0.28; P = 0.45; 3 trials, 249 participants, low quality of evidence). Seven trials (692 participants) evaluated fatigue. There is moderate quality of evidence that exercise improves fatigue (SMD 0.24; 95% CI 0.08 to 0.40; P = 0.003). Eight studies evaluated various aspects of physical performance (e.g. aerobic capacity, cardiovascular fitness), but none of them could be pooled in a meta-analysis. In seven trials there is a tendency or statistically significant effect favouring the exercise group (very low quality of evidence). Three trials (266 participants) investigated serious adverse events (SAEs) (e.g. bleeding, fever, pneumonia, deep vein thrombosis, and infection), and one trial (122 participants) assessed adverse events (AEs). There is no evidence for a difference between arms in terms of SAEs (RR 1.44; 95% CI 0.96 to 2.18; P = 0.06) or AEs (RR 7.23; 95% CI 0.38 to 137.05; P = 0.19); both findings are based on low quality of evidence. Authors' conclusions There is no evidence for differences in mortality between the exercise and control groups. Physical exercise added to standard care can improve quality of life, especially physical functioning, depression and fatigue. Currently, there is inconclusive evidence regarding anxiety, physical performance, serious adverse events and adverse events. We need further trials with more participants and longer follow-up periods to evaluate the effects of exercise intervention for people suffering from haematological malignancies. Furthermore, we need trials with overall survival as the primary outcome to determine whether the suggested benefits will translate into a survival advantage. To enhance comparability of study data, development and implementation of core sets of measuring devices would be helpful.