Objective ① To document the way in which allocation concealment is described and coded for studies included in Cochrane Reviews.②To feed back any gaps or miscodings to individual review groups.③ To suggest changes and expansions to advice on how to code and describe allocation concealment methods.Methods The coding and description of methods of allocation concealment for studies included in all 1 596 reviews on issue 1, 2003 of The Cochrane Library are being extracted.So far results are available for 10.8% (173/1 596) of reviews containing 1 844 studies, from 10 Collaborative Review Groups (CRGs).Discrepancies, and inconsistencies with the Cochrane Reviewers’ Handbook, are being documented and analysed.Results The current coding of the adequacy of allocation concealment in studies included in Cochrane reviews is not likely to be very accurate.This is due to failure to describe methods of allocation concealment (38.6% of the sample of 1 844 studies) as well as miscoding (at least an additional 9.2%).The most common method for studies coded A was some variation of envelope use (133/675-19.7% of all A codes). The most common "method" for studies coded B was method unclear or not described in the report of the study (426/665, 64% of all B codes).Conclusions Since adequate allocation concealment is so important in protecting against bias in randomised controlled trials, it needs to be accurately coded and described.We need to improve how this is done for studies included in Cochrane Reviews.Since over half the studies coded as D were likely to have been where reviewers omitted to enter a code, the default should be changed from D to "code not supplied".Structural changes to RevMan are suggested-ideally the addition of a separate new study quality assessment table with fixed headings as well as the facility to enter free text.Suggestions for improving coding in particular reviews will be fed back to CRGs in the next stages of this project.Suggestions for additions to the Cochrane Reviewers’ Handbook are also made.
Sir Iain Chalmers, the cofounder of the UK Cochrane Centre and The Cochrane Collaboration, a distinguished and talented leader, a meditative scholar, a responsive researcher, a zealous challenger, has fully devoted himself to the pursuit of better care for patients. His splendid achievements and reputations have never halted his endeavor. This biographic sketch is intended to shed light on the critical moments that have made Sir. Iain Chalmers such an extraordinary man.
Archibald Leman Cochrane（1909 to 1988）was a physician and clinical epidemiologist from the UK. The basic theroy of evidence-based medicine was established because of his influential book, Effectiveness and Efficiency: Random Reflections on Health Services published in 1972. The randomized controlled trial and systematic review promoted by Archie has become the key stone of evidence-based medicine. He was known as one of the forefathers of evidence-based medicine because of his outstanding contribution. In commemoration of Arichie Cochrane, The Cochrane Collaboration was named after him. His legendary life story and the early stages of the development of evidence-based medicine are introduced in this article.
Until Issue 2 in 2008, the Cochrane Database of Systematic Reviews had included 23 systematic reviews concerning colorectal tumors by the colorectal cancer group. These reviews involved prevention, diagnosis, treatment, prognosis and follow-up. The preventive ability of non-steroid anti-inflammatory drugs, accuracy of chromoscopy, shortterm outcomes of laparoscopic colorectal resection and outcomes of laparoscopic total mesorectal excision were confirmed. Meanwhile, the effect of dietary fibre in prevention, mechanical preoperative preparation, and prophylactic anastomotic drainage was questioned. Because of the low quality of trials, no firm conclusions were revealed in some reviews, such as traditional Chinese medicine in chemotherapy. Through the study of Cochrane systematic reviews, medical practitioners and researchers can obtain high-quality evidence, and identify future research direction in the field of colorectal cancer.
Backgroud Iodine deficiency is the main cause for potentially preventable mental retardation in childhood and is still prevalent in large parts of the world. Objectives To assess the effects of iodised salt in comparison with other forms of iodine supplementation or placebo in the prevention of iodine deficiency disorders.Search strategy We searched the Cochrane Library, Medline, the Register of Chinese trials developed by the Chinese Cochrane Centre, and the Chinese Med Database. We performed handsearching of a number of journals (Chinese Journal of Control of Endemic Diseases, Chinese Journal of Epidemiology, Chinese Journal of Preventive Medicine, and Studies of Trace Elements and Health up to February 2001), and searched reference lists, databases of ongoing trials and the Internet. Date of latest search: November 2001. Selection Criteria We included prospective controlled studies of iodised salt versus other forms of iodine supplementation or placebo in people living in areas of iodine deficiency. Studies reported mainly goitre rates and urinary iodine excretion as outcome measures. Data collection amp; analysis As the studies identified were not sufficiently similar and not of sufficient quality, we did not do a meta-analysis but summarised the data in a narrative format. Main results We found six prospective controlled trials relating to our question. Four of these were described as randomised controlled trials, one was a prospective trial that did not specify allocation to comparison groups, and one was a large population-based study comparing different interventions. Comparison interventions included non-iodised salt, iodised water, iodised oil, iodation with potassium iodide versus potassium iodate. Numbers of participants in the trials ranged from 35 to 334; over 20 000 people were included in the population-based study. There was a tendency towards goitre reduction with iodised salt, although this was not significant in all studies. There was aim an improved iodine status in most studies (except in small children in one of the studies), although urinary iodine excretion did not always reach the levels recommended by the WHO. Reviewers’ conclusions The results suggest that iodised salt is an effective and safe means of improving iodine status. However, high quality controlled studies are needed to address questions of dosage and best means of iodine supplementation in different population groups.
Having searched The Cochrane Library (Issue 4, 2005), we found: fluoride can reduce the occurrence and severity of white spot lesions; removal of premature contacts of the primary teeth can prevent posterior crossbite; expanding the top teeth can decrease the risk of a posterior crossbite; CSF may help retaining teeth; clear overlay retainer may settle teeth quicker than Hawley retainer; adhesives for fixed orthodontic brackets is still in dispute.
Evidence and its quality are of the key issues in evidence-based medicine. The Cochrane Library is an electronic publication, updated quarterly every year in CD-Rom and internet format, designed to provide high quality evidence to inform people receiving care, and those responsible for treating, teaching, research and administration at all levels. This paper aims to help readers how to access its information as well.
Background Tongxinluo capsule is a new drug for cardio- cerebral vascular diseases on the national essential drug list of China, and the second-class award of National Science and Technology Development of China, 2001. Objective This review aims to assess the effect (harms and benefits) of Tongxinluo capsule for unstable angina. Search strategy electronic searchs The Cochrane Heart Review Group specialised trials register,The Cochrane Controlled Trials Register, published in the latest issue of the Cochrane Library, MEDLINE, EMBASE, CBM, Chinese Cochrane Centre Controlled Trials Register, Current Controlled Trials (www. controlled-trials. com), The National Research Register Handsearchs We will search 83 journals of Chinese traditional medicine. Inclusion riteria We will include randomised controlled trials of Tonxinluo capsule versus placebo or other current phamarcotherapy or other Chinese medicinal herbs in the participants with unstable angina pectoris. Studies will report mortality (sudden death from acute myocardial infarction), severity of angina pectoris, frequency of acute attack angina, ECG improvement, rate of dosage reducing or taking frequency of nitroglycerine and symptom improvement, etc. Data analysis Data will be included in a meta-analysis if they are available, of sufficient quality and sufficiently similar.
Objective To analyze acupuncture resources in the Cochrane Database of Systematic Reviews (CDSR). Methods We identified acupuncture literature from CDSR (2008 year) electronically. W analyzed this literature by research time date, author, study contents, and conCochrane Library usions.?Results?? ? We initially found 82 articles. Finally, we identified 67 systematic reviews. The number of acupuncture articles has increased all over the world with higher growth rate in China than overseas. The disease spectrum of acupuncture treatment increased widely, focusing on nervous system diseases and pain diseases. Eight articles (25.8%) definitely supported the efficacy of acupuncture. Twenty two articles (71%) considered the efficacy of acupuncture as uncertain owning to insufficient evidence. Just one article expressed that acupuncture treatment was ineffective according to current evidence.
Background Hepatitis B virus infection is a serious health problem worldwide. Traditional Chinese medicinal herbs have been widely used to treat chronic liver diseases, and many controlled trials have been done to investigate their efficacy. Objectives To assess the efficacy and safety of traditional Chinese medicinal herbs for chronic hepatitis B infection. Search strategy Searches were applied to the following electronic databases: the CHBG Trials Register, the Cochrane Complementary Medicine Field Trials-Register, the Cochrane Library, MEDLINE, EMBASE and BIOSIS. Five Chinese journals and conference proceedings were handsearched. No language restriction was used. Selection criteria Randomized or quasi-randomized trials with at least three months follow-up. Thais of Chinese medicinal herbs (single or compound) compared with placebo, no intervention, general non-specific treatment or interferon treatment were included. Trials of Chinese medicinal herbs plus interferon versus interferon alone were also included. Trials could be double-blind, single-blind or not blinded. Data collection and analysis Data were extracted independently by two reviewers. The methodological quality of trials was evaluated using the Jadad-scale plus allocation concealment. Intention-to-treat analyses were performed. Main Resuits Nine randomized trials, including 936 patients, met the inclusion criteria. Methodological quality was considered adequate in only one trial. There was a significant funnel plot asymmetry (regression coefficient= 3.37, standard error 1.40, P=0.047). Ten different medicinal herbs were tested in the nine trials. Compared to non-specific treatment or placebo, Fuzheng Jiedu Tang (compound of herbs) showed significantly positive effects on clearance of serum HBsAg, HBeAg, and HBV DNA; Polyporus umbellatus, polysaccharide on serum HBeAg and HBV DNA; Phyllanthus amarus on serum HBeAg. Phyllanthus compound and kurorinone showed no significant effect on clearance of serum HBeAg and HBV DNA and on alanine aminotransferase normalization compared to interferon treatment. There were no significant effects of the other examined herbs. Reviewer’s conclusions Some Chinese medicinal herbs may work in chronic hepatitis B. However, the evidence too weak to recommend any single herb. Rigorously designed, randomized, double-blind, placebo-controlled trials are required.