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.

Incentive spirometry for preventing pulmonary complications after coronary artery bypass graft

Abstract: Background Incentive spirometry (IS) is a treatment technique that uses a mechanical device to reduce pulmonary complications during postoperative care. This is an update of a Cochrane review first published in 2007. Objectives Update the previously published systematic review to compare the effects of IS for preventing postoperative pulmonary complications in adults undergoing coronary artery bypass graft (CABG). Search methods We searched CENTRAL and DARE on The Cochrane Library (Issue 2 of 4 2011), MEDLINE OVID (1948 to May 2011), EMBASE (1980 to Week 20 2011), LILACS (1982 to July 2011) , the Physiotherapy Evidence Database (PEDro) (1980 to July 2011), Allied & Complementary Medicine (AMED) (1985 to May 2011), CINAHL (1982 to May 2011). Selection criteria Randomised controlled trials comparing IS with any type of prophylactic physiotherapy for prevention of postoperative pulmonary complications in adults undergoing CABG. Data collection and analysis Two reviewers independently evaluated trial quality using the guidelines of the Cochrane Handbook for Systematic Reviews and extracted data from included trials. For continuous outcomes, we used the generic inverse variance method for meta-analysis and for dichotomous data we used the Peto Odds Ratio. Main results This update included 592 participants from seven studies (two new and one that had been excluded in the previous review in 2007. There was no evidence of a difference between groups in the incidence of any pulmonary complications and functional capacity between treatment with IS and treatment with physical therapy, positive pressure breathing techniques (including continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP) and intermittent positive pressure breathing (IPPB), active cycle of breathing techniques (ACBT) or preoperative patient education. Patients treated with IS had worse pulmonary function and arterial oxygenation compared with positive pressure breathing. Based on these studies there was no improvement in the muscle strength between groups who received IS demonstrated by maximal inspiratory pressure and maximal expiratory pressure. Authors' conclusions Our update review suggests there is no evidence of benefit from IS in reducing pulmonary complications and in decreasing the negative effects on pulmonary function in patients undergoing CABG. In view of the modest number of patients studied, methodological shortcomings and poor reporting of the included trials, these results should still be interpreted cautiously. An appropriately powered trial of high methodological rigour is needed to determine if there are patients who may derive benefit from IS following CABG.

Dam Removal Increases American Eel Abundance in Distant Headwater Streams

Abstract: American eel Anguilla rostrata abundances have undergone significant declines over the last 50 years, and migration barriers have been recognized as a contributing cause. We evaluated eel abundances in headwater streams of Shenandoah National Park, Virginia, to compare sites before and after the removal of a large downstream dam in 2004 (Embrey Dam, Rappahannock River). Eel abundances in headwater streams increased significantly after the removal of Embrey Dam. Observed eel abundances after dam removal exceeded predictions derived from autoregressive models parameterized with data prior to dam removal. Mann–Kendall analyses also revealed consistent increases in eel abundances from 2004 to 2010 but inconsistent temporal trends before dam removal. Increasing eel numbers could not be attributed to changes in local physical habitat (i.e., mean stream depth or substrate size) or regional population dynamics (i.e., abundances in Maryland streams or Virginia estuaries). Dam removal was associated with d...

Evolution of poor reporting and inadequate methods over time in 20 920 randomised controlled trials included in Cochrane reviews: research on research study.

Abstract: Objective To examine how poor reporting and inadequate methods for key methodological features in randomised controlled trials (RCTs) have changed over the past three decades. Design Mapping of trials included in Cochrane reviews. Data sources Data from RCTs included in all Cochrane reviews published between March 2011 and September 2014 reporting an evaluation of the Cochrane risk of bias items: sequence generation, allocation concealment, blinding, and incomplete outcome data. Data extraction For each RCT, we extracted consensus on risk of bias made by the review authors and identified the primary reference to extract publication year and journal. We matched journal names with Journal Citation Reports to get 2014 impact factors. Main outcomes measures We considered the proportions of trials rated by review authors at unclear and high risk of bias as surrogates for poor reporting and inadequate methods, respectively. Results We analysed 20 920 RCTs (from 2001 reviews) published in 3136 journals. The proportion of trials with unclear risk of bias was 48.7% for sequence generation and 57.5% for allocation concealment; the proportion of those with high risk of bias was 4.0% and 7.2%, respectively. For blinding and incomplete outcome data, 30.6% and 24.7% of trials were at unclear risk and 33.1% and 17.1% were at high risk, respectively. Higher journal impact factor was associated with a lower proportion of trials at unclear or high risk of bias. The proportion of trials at unclear risk of bias decreased over time, especially for sequence generation, which fell from 69.1% in 1986-1990 to 31.2% in 2011-14 and for allocation concealment (70.1% to 44.6%). After excluding trials at unclear risk of bias, use of inadequate methods also decreased over time: from 14.8% to 4.6% for sequence generation and from 32.7% to 11.6% for allocation concealment. Conclusions Poor reporting and inadequate methods have decreased over time, especially for sequence generation and allocation concealment. But more could be done, especially in lower impact factor journals.

Interaction of St John's wort with conventional drugs: systematic review of clinical trials

Abstract: Objective To determine the methodological quality of clinical trials that examined possible interactions of St John9s wort with conventional drugs, and to examine the results of these trials. Design Systematic review. Data sources Electronic databases from inception to April 2004, reference lists from published reports, and experts in the field. Study selection Eligible studies were prospective clinical trials evaluating the pharmacokinetic effect of St John9s wort on the metabolism of conventional drugs. Data extraction Two reviewers selected studies for inclusion and independently extracted data. Data synthesis 22 pharmacokinetic trials studied an average of 12 (SD 5) participants; 17 trials studied healthy volunteers and five studied patients. Most (17) studies used a “before and after” design; four studies used control groups other than the active group. Three studies randomised the sequence of administration or the participants to study arms or periods; three studies blinded participants or investigators. In 15 trials, investigators independently assayed the herb. Of 19 trials with available plasma data, three found no important interaction (change in area under the curve Conclusion Clinicians and patients should beware of possible decreases in the systemic bioavailability of conventional drugs when taken concomitantly with St John9s wort.