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To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
To Cochrane or not: that's the question
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To Cochrane or not: that's the question

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the role of Cochrane collaboration and specifically the menstrual disorder & subfertility group is illustrated . simple explanation how to use cochrane reviews is done.

the role of Cochrane collaboration and specifically the menstrual disorder & subfertility group is illustrated . simple explanation how to use cochrane reviews is done.

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  • 1. AUSTRALASIAN COCHRANE CENTRE To Cochrane or not: that's the question 1 Professor Hesham Al-Inany Editor, Cochrane Menstrual Disorders & Subfertility Group Editor, British Journal of Obstetrics & gynecology Cairo University Egypt
  • 2. AUSTRALASIAN COCHRANE CENTRE Preparing, maintaining and disseminating systematic reviews of the effects of health care THE COCHRANE COLLABORATION
  • 3. AUSTRALASIAN COCHRANE CENTRE Antenatal corticosteroids for preterm birth • Survey: • 1980 RCOG survey: 42% • 1984 Belgium : 32% • 1990 UK centers : 58% • 1992 US Obs: 8-34% • NIH : •”corticosteroid Rx is indicated for women at risk of premature delivery ……….. and will result in a substantial decrease in neonatal morbidity and mortality as well as substantial savings”
  • 4. AUSTRALASIAN COCHRANE CENTRE Learning objectives  Why are systematic reviews important?  Why Cochrane systematic reviews?  How to join for a Cochrane systematic review? 4
  • 5. AUSTRALASIAN COCHRANE CENTRE How do we treat our patients?  Using evidence from high quality research to answer specific questions
  • 6. AUSTRALASIAN COCHRANE CENTRE For example: In women with infertility does acupuncture improve pregnancy outcomes ?
  • 7. AUSTRALASIAN COCHRANE CENTRE 7 RCT : Gold standard Participants RandomlyAssigned Intervention Group Control Group Follow-up Follow-up Intervention Group Control Group
  • 8. AUSTRALASIAN COCHRANE CENTRE But there are many RCTs on this topic  Some with conflicting results  Some with small number of participants
  • 9. AUSTRALASIAN COCHRANE CENTRE Why are systematic reviews useful?
  • 10. AUSTRALASIAN COCHRANE CENTRE Systematic review  Uses tools to summarise the results of a number of trials/studies  Systematic and scientific methodology  Helpful in clinical decision making
  • 11. AUSTRALASIAN COCHRANE CENTRE Advantages • To increase power, Many individual studies are too small to detect small effects, but when several are combined there is a higher chance of detecting an effect. • To improve precision: The estimation of an intervention effect can be improved when it is based on more data.
  • 12. AUSTRALASIAN COCHRANE CENTRE Review : Steff Comparison: 01 Absence of evidence and Evidence of absence Outcome: 01 Increasing the amount of data... Study Treatment Control OR (fixed) OR (fixed) or sub-category n/N n/N 95% CI 95% CI 1 study 10/100 15/100 0.63 [0.27, 1.48] 2 studies 20/200 30/200 0.63 [0.34, 1.15] 3 studies 30/300 45/300 0.63 [0.38, 1.03] 4 studies 40/400 60/400 0.63 [0.41, 0.96] 5 studies 50/500 75/500 0.63 [0.43, 0.92] 0.1 0.2 0.5 1 2 5 10 Favours treatment Favours control In the example below, as more data is included, the overall odds ratio remains the same but the confidence interval decreases. It is not true that there is ‘no difference’ shown in the first rows of the plot – there just isn’t enough power to show a statistically significant result.
  • 13. AUSTRALASIAN COCHRANE CENTRE 1. Clear objectives stated with a well formulated clinical question 2. Inclusion and exclusion criteria stated 3. Comprehensive search strategy 4. Systematic approach with all relevant studies 5. Excluded studies listed with reasons 6. Trial results are pooled if possible (meta-analysis) Features not in narrative reviews
  • 14. AUSTRALASIAN COCHRANE CENTRE 1. Clearly stated objective with clinical question Participants Intervention Comparison Outcome In women with infertility does acupuncture improve pregnancy outcomes ?
  • 15. AUSTRALASIAN COCHRANE CENTRE 2. Inclusion and exclusion criteria pre-stated Participants Intervention Comparison Outcome In women with infertility does acupuncture treatment improve pregnancy outcomes ? • Women <45 yo • Infertility for > 1 yr • No other Rx or ART? Acupunture Live birth rate Adverse events Sham Acupuncture or no treatment
  • 16. AUSTRALASIAN COCHRANE CENTRE 3. Comprehensive search for all studies All databases are searched to avoid publication bias? MEDLINE, EMBASE, CINHAL and others
  • 17. AUSTRALASIAN COCHRANE CENTRE Publication Bias  Research with statistically significant results is more likely to be submitted for publication and more likely to be published.
  • 18. AUSTRALASIAN COCHRANE CENTRE Advanced ovarian cancer Comparison: combination chemotherapy versus single chemotherapy Published trials 0.7 1 1.3 Registered trials Simes 1987 Outcome: mortality
  • 19. AUSTRALASIAN COCHRANE CENTRE Not restricted to English language
  • 20. AUSTRALASIAN COCHRANE CENTRE 4. Systematic approach Independent tasks by 2 or more reviewers:  Selection of studies for inclusion and tabulated  Data extraction  Quality assessment  Data entry Disagreements resolved by 3rd party
  • 21. AUSTRALASIAN COCHRANE CENTRE 5. Excluded studies listed  All excluded studies included in a table  Reasons given for exclusion  Transparency minimises bias
  • 22. AUSTRALASIAN COCHRANE CENTRE 6. Pooling of results using meta-analysis if appropriate and possible What is a meta-analysis?  A statistical tool to combine results of studies  Using Revman software (free to download)  Valuable way to display a summary of the trials
  • 23. AUSTRALASIAN COCHRANE CENTRE Why do we need it  To avoid Type II error: Investigators did not detect a difference when a difference actually exists
  • 24. AUSTRALASIAN COCHRANE CENTRE Review : Steff Comparison: 01 Absence of evidence and Evidence of absence Outcome: 01 Increasing the amount of data... Study Treatment Control OR (fixed) OR (fixed) or sub-category n/N n/N 95% CI 95% CI 1 study 10/100 15/100 0.63 [0.27, 1.48] 2 studies 20/200 30/200 0.63 [0.34, 1.15] 3 studies 30/300 45/300 0.63 [0.38, 1.03] 4 studies 40/400 60/400 0.63 [0.41, 0.96] 5 studies 50/500 75/500 0.63 [0.43, 0.92] 0.1 0.2 0.5 1 2 5 10 Favours treatment Favours control
  • 25. AUSTRALASIAN COCHRANE CENTRE Graphic Display: ß blockers in secondary prevention after myocardial infarction.
  • 26. AUSTRALASIAN COCHRANE CENTRE Cumulative Meta-analysis
  • 27. AUSTRALASIAN COCHRANE CENTRE Meta-analysis vs. a “Mega-study” Single large studies are liable to:  Long duration  Huge funding a drug that reduces mortality by 10% from myocardial infarction may need a study including 10.000 patients
  • 28. AUSTRALASIAN COCHRANE CENTRE  Why are systematic reviews important?  Why Cochrane systematic reviews?  How to prepare a protocol for a Cochrane systematic review 28
  • 29. AUSTRALASIAN COCHRANE CENTRE Advantages of Cochrane reviews  Updating of reviews regularly  Methodologically robust  Less likely to be biased
  • 30. AUSTRALASIAN COCHRANE CENTRE How do (Cochrane) systematic reviews reduce bias?  Prestated methods published  Limit publication bias (very comprehensive search)  Limit commercial and industry sponsorship of reviews
  • 31. AUSTRALASIAN COCHRANE CENTRE Studies with funding bias are more likely to have favourable results (Lundh et al 2012)  Add reviews on this topic
  • 32. AUSTRALASIAN COCHRANE CENTRE “..we observed far superior reporting standards of Cochrane reviews compared to non- Cochrane therapeutic ones.” “For therapeutic reviews, all the Cochrane ones reported assessing the quality of included studies whereas only half of the non- Cochrane did.” “The seven industry supported reviews that had conclusions recommended the experimental drug without reservations, compared with none of the Cochrane reviews, although the estimated treatment effect was similar on average Better quality reviews
  • 33. AUSTRALASIAN COCHRANE CENTRE Our structure • more than 27,000 people in over 100 countries  almost all volunteers • decentralised structure  52 Cochrane Review Groups (CRGs) • specific areas of health care • first point of contact for authors • international and multidisciplinary • largely funded by government grants
  • 34. AUSTRALASIAN COCHRANE CENTRE Cochrane centers all over the world
  • 35. AUSTRALASIAN COCHRANE CENTREwww.thecochranelibrary.
  • 36. AUSTRALASIAN COCHRANE CENTRE Cochrane Reviews Randomised controlled trials Methodology papers
  • 37. AUSTRALASIAN COCHRANE CENTRE
  • 38. AUSTRALASIAN COCHRANE CENTRE
  • 39. AUSTRALASIAN COCHRANE CENTRE
  • 40. AUSTRALASIAN COCHRANE CENTRE Displaying results graphically  Revman software produces forest plots
  • 41. AUSTRALASIAN COCHRANE CENTRE there’s a label to tell you what the comparison is and what the outcome of interest is
  • 42. AUSTRALASIAN COCHRANE CENTRE At the bottom there’s a horizontal line. This is the scale measuring the treatment effect.
  • 43. AUSTRALASIAN COCHRANE CENTRE The vertical line in the middle is where the treatment and control have the same effect – there is no difference between the two
  • 44. AUSTRALASIAN COCHRANE CENTRE For each study there is an id The data for each trial are here, divided into the experimental and control groups This is the % weight given to this study in the pooled analysis
  • 45. AUSTRALASIAN COCHRANE CENTRE •Each study is given a blob, placed where the data measure the effect. •The size of the blob is proportional to the % weight •The horizontal line is called a confidence interval and is a measure of how we think the result of this study might vary with the play of chance. •The wider the horizontal line is, the less confident we are of the observed effect. The label above the graph tells you what statistic has been used The data shown in the graph are also given numerically
  • 46. AUSTRALASIAN COCHRANE CENTRE The pooled analysis is given a diamond shape where the widest bit in the middle is located at the calculated best guess (point estimate), and the horizontal width is the confidence interval Definition of a 95% confidence interval: If a trial was repeated 100 times, then 95 out of those 100 times, the best guess (point estimate) would lie within this interval.
  • 47. AUSTRALASIAN COCHRANE CENTRE Reading the graphs What outcome? What measure of effect size? The events The pooled ORs And confidence intervals weighting?
  • 48. AUSTRALASIAN COCHRANE CENTRE Reading the graphs What measure of effect size? And confidence intervals The pooled ORs Heterogeneity The events
  • 49. AUSTRALASIAN COCHRANE CENTRE Limitations ???  Takes long time to publish and huge effort to be done  Authors may lose interest in updating SR  Not considered for PhD as main research (reviewer not author ??) 49
  • 50. AUSTRALASIAN COCHRANE CENTRE Practical tips for new comers  no specific criteria to be an author  Determine which field of interest  Choose a very specific point  formulate a question  make a quick search for RCTs  preferably not more than 6 RCTs
  • 51. AUSTRALASIAN COCHRANE CENTRE The life cycle of a Cochrane review Title (registered) Prepare Protocol Register Protocol Systematic Review Review online Time Frame 6 Months 12 Months Lifelong editorial + external review searches inclusions quality data extraction meta-analysis editorial + external review outside comments and criticisms new data 2 or more reviewers
  • 52. AUSTRALASIAN COCHRANE CENTRE What support is available?  an on-line systematic review training programmes can be accessed at:  http://www.cochrane-net.org/openlearning  http://www.cochrane.org/training/authors
  • 53. AUSTRALASIAN COCHRANE CENTRE The end..... 54 http://www.cochrane.org/about-us /newcomers-guide.

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