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.

Bisphosphonate therapy for osteogenesis imperfecta.

Abstract: Background Osteogenesis imperfecta is caused by a genetic defect resulting in an abnormal type I collagen bone matrix which typically results in multiple fractures with little or no trauma. Bisphosphonates are used in an attempt to increase bone mineral density and reduce these fractures in people with osteogenesis imperfecta. This is an update of a previously published Cochrane Review. Objectives To assess the effectiveness and safety of bisphosphonates in increasing bone mineral density, reducing fractures and improving clinical function in people with osteogenesis imperfecta. Search methods We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Inborn Errors of Metabolism Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of journals and conference proceedings. We additionally searched PubMed and major conference proceedings. Date of the most recent search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Register: 28 April 2016. Selection criteria Randomised and quasi-randomised controlled trials comparing bisphosphonates to placebo, no treatment, or comparator interventions in all types of osteogenesis imperfecta. Data collection and analysis Two authors independently extracted data and assessed the risk of bias of the included trials. Main results Fourteen trials (819 participants) were included. Overall, the trials were mainly at a low risk of bias, although selective reporting was an issue in several of the trials. Data for oral bisphosphonates versus placebo could not be aggregated; a statistically significant difference favouring oral bisphosphonates in fracture risk reduction and number of fractures was noted in two trials. No differences were reported in the remaining three trials which commented on fracture incidence. Five trials reported data for spine bone mineral density; all found statistically significant increased lumbar spine density z scores for at least one time point studied. For intravenous bisphosphonates versus placebo, aggregated data from two trials showed no statistically significant difference for the number of participants with at least one fracture, risk ratio 0.56 (95% confidence interval 0.30 to 1.06). In the remaining trial no statistically significant difference was noted in fracture incidence. For spine bone mineral density, no statistically significant difference was noted in the aggregated data from two trials, mean difference 9.96 (95% confidence interval -2.51 to 22.43). In the remaining trial a statistically significant difference in mean per cent change in spine bone mineral density z score favoured intravenous bisphosphonates at six and 12 months. Data describing growth, bone pain, and functional outcomes after oral or intravenous bisphosphonate therapy, or both, as compared to placebo were incomplete among all studies, but do not show consistent improvements in these outcomes. Two studies compared different doses of bisphosphonates. No differences were found between doses when bone mineral density, fractures, and height or length z score were assessed. One trial compared oral versus intravenous bisphosphonates and found no differences in primary outcomes. Two studies compared the intravenous bisphosphonates zoledronic acid and pamidronate. There were no significant differences in primary outcome. However, the studies were at odds as to the relative benefit of zoledronic acid over pamidronate for lumbosacral bone mineral density at 12 months. Authors' conclusions Bisphophonates are commonly prescribed to individuals with osteogenesis imperfecta. Current evidence, albeit limited, demonstrates oral or intravenous bisphosphonates increase bone mineral density in children and adults with this condition. These were not shown to be different in their ability to increase bone mineral density. It is unclear whether oral or intravenous bisphosphonate treatment consistently decreases fractures, though multiple studies report this independently and no studies report an increased fracture rate with treatment. The studies included here do not show bisphosphonates conclusively improve clinical status (reduce pain; improve growth and functional mobility) in people with osteogenesis imperfecta. Given their current widespread and expected continued use, the optimal method, duration of therapy and long-term safety of bisphosphonate therapy require further investigation. In addition, attention should be given to long-term fracture reduction and improvement in quality of life indicators.

Manual versus powered toothbrushing for oral health

Abstract: BACKGROUND: Removing dental plaque may play a key role maintaining oral health. There is conflicting evidence for the relative merits of manual and powered toothbrushing in achieving this. OBJECTIVES: To compare manual and powered toothbrushes in relation to the removal of plaque, the health of the gingivae, staining and calculus, dependability, adverse effects and cost. SEARCH STRATEGY: We searched the Cochrane Oral Health Group Trials Register (to 17/06/2004) and Central Register of Controlled Trials (The Cochrane Library Issue 2, 2004); MEDLINE (January 1966 to week 2 June 2004); EMBASE (January 1980 to week 2 2004) and CINAHL (January 1982 to week 2 June 2004). Manufacturers were contacted for additional data. SELECTION CRITERIA: Trials were selected for the following criteria: design-random allocation of participants; participants - general public with uncompromised manual dexterity; intervention - unsupervised manual and powered toothbrushing for at least 4 weeks. Primary outcomes were the change in plaque and gingivitis over that period. DATA COLLECTION AND ANALYSIS: Six authors independently extracted information. The effect measure for each meta-analysis was the standardised mean difference (SMD) with 95% confidence intervals (CI) using random-effects models. Potential sources of heterogeneity were examined, along with sensitivity analyses for quality and publication bias. For discussion purposes SMD was translated into percentage change. MAIN RESULTS: Forty-two trials, involving 3855 participants, provided data.Brushes with a rotation oscillation action removed plaque and reduced gingivitis more effectively than manual brushes in the short term and reduced gingivitis scores in studies over 3 months. For plaque at 1 to 3 months the SMD was -0.43 (95% CI: -0.72 to -0.14), for gingivitis SMD -0.62 (95% CI: -0.90 to -0.34) representing an 11% difference on the Quigley Hein plaque index and a 6% reduction on the Loe and Silness gingival index. At over 3 months the SMD for plaque was -1.29 (95% CI: -2.67 to 0.08) and for gingivitis was -0.51 (-0.76 to -0.25) representing a 17% reduction on the Ainamo Bay bleeding on probing index. There was heterogeneity between the trials for the short-term follow up. Sensitivity analyses revealed the results to be robust when selecting trials of high quality. There was no evidence of any publication bias.No other powered designs were as consistently superior to manual toothbrushes.Cost, reliability and side effects were inconsistently reported. Any reported side effects were localised and temporary. AUTHORS' CONCLUSIONS: Powered toothbrushes with a rotation oscillation action reduce plaque and gingivitis more than manual toothbrushing.Observation of methodological guidelines and greater standardisation of design would benefit both future trials and meta-analyses.

Assessment of methodological quality of primary studies by systematic reviews: results of the metaquality cross sectional study.

Abstract: Objectives To describe how the methodological quality of primary studies is assessed in systematic reviews and whether the quality assessment is taken into account in the interpretation of results. Data sources Cochrane systematic reviews and systematic reviews in paper based journals. Study selection 965 systematic reviews (809 Cochrane reviews and 156 paper based reviews) published between 1995 and 2002. Data synthesis The methodological quality of primary studies was assessed in 854 of the 965 systematic reviews (88.5%). This occurred more often in Cochrane reviews than in paper based reviews (93.9% v 60.3%, P < 0.0001). Overall, only 496 (51.4%) used the quality assessment in the analysis and interpretation of the results or in their discussion, with no significant differences between Cochrane reviews and paper based reviews (52% v 49%, P = 0.58). The tools and methods used for quality assessment varied widely. Conclusions Cochrane reviews fared better than systematic reviews published in paper based journals in terms of assessment of methodological quality of primary studies, although they both largely failed to take it into account in the interpretation of results. Methods for assessment of methodological quality by systematic reviews are still in their infancy and there is substantial room for improvement.

Time to publication for results of clinical trials

Abstract: Background It has been suggested that a time-lag bias exists whereby research studies with striking results are more likely to be stopped earlier than originally planned, published quicker, or both. If time-lag bias exists, new interventions might be mistakenly assumed to be effective. Objectives To study the extent to which time to publication of a clinical trial is influenced by the significance of its result. Search methods Studies were identified by searching the Cochrane Methodology Register (The Cochrane Library, Issue 3, 2005), MEDLINE (1966 to May 2005), EMBASE (1980 to May 2005), Science Citation Index (June 2005) and by handsearching journals and conference abstracts. Selection criteria Studies were eligible if they contained analyses of any aspect of the time to publication of clinical trials and tracked the publication of a cohort of clinical trials. Data collection and analysis Data extraction was performed independently by two authors. Data were extracted on the median time from the date the trial started to the date of publication. Data were also extracted on source of trials under investigation; source of funding; area of health care; means by which the publication status of these trials were sought; and methodological quality of the empirical study. Main results Two studies with a total of 196 trials met the inclusion criteria. In both studies just over half of all trials had been published in full. Trials with positive results (i.e. statistically significant in favour of the experimental arm) were published in approximately 4 to 5 years. Trials with null or negative results (i.e. not statistically significant or statistically significant in favour of the control arm) were published after about 6 to 8 years. One study suggested that this difference could, in part, be attributed to the length of time taken to publish the results of a trial once follow up has been completed. This study showed that trials with null or negative findings took, on average, just over a year longer to be published than those with positive results. Authors' conclusions Our review shows that trials with positive results are published sooner than other trials. This has important implications for the timing of the initiation and updating of a review, especially if there is an association between the inclusion of a trial in a review and its publication status. It is of particular concern when one considers reviews containing only a small number of studies.

Cochrane in context: Vaccines for measles, mumps and rubella in children

Abstract: Cochrane Review: Vaccines for measles, mumps and rubella in children Demicheli V, Rivetti A, Debalini MG, Di Pietrantonj C. Vaccines for measles, mumps and rubella in children. Cochrane Database of Systematic Reviews 2012, Issue 2. Art. No.: CD004407. DOI: 10.1002/14651858.CD004407.pub3 This companion piece to the review, “Vaccines for measles, mumps and rubella in children,” contains the following pieces: The abstract of the review A commentary from one or more of the review authors, explaining why the review team felt the review was an important one to produce A commentary from Joan Robinson, Editor-in-chief, outlining the review's findings A review of clinical practice guidelines from the American Academy of Pediatrics, the Canadian Paediatric Society and the National Institute for Health and Care Excellence (NICE), United Kingdom Some other recently published references on this topic