Trusted evidence. Informed decisions. Better health. Cochrane Systematic Reviews & Meta analyses

Transcription

1 Trusted evidence. Informed decisions. Better health. Cochrane Systematic Reviews & Meta analyses Assoc. Prof. Dr Norhayati Mohd Noor MBBS, MCommMed (Family Health), PhD USM Cochrane Coordinating Centre School of Medical Sciences, USM

2 Outline Cochrane Collaboration Principles of systematic reviews Principles of meta analysis Cochrane process Cochrane Library Cochrane translation

3 How do you know if one treatment will work better than another, or if it will do more harm than good?" Cochrane Reviews answer this question

4 Researchers Cochrane reviews reveal where new research is needed and where no new research is needed Healthcare providers Cochrane reviews can be used to make decisions about healthcare for an individual patient or for changing practice They are used in clinical practice guidelines Policy makers Cochrane reviews are used in policy briefs Funding and regulatory decisions The public (Healthcare Consumers)

5 One full text Cochrane review is accessed somewhere in the world every second Who are they?

6 Archie Cochrane s challenge It is surely a great criticism of our profession that we have not organised a critical summary, by specialty or subspecialty, adapted periodically, of all relevant randomised controlled trials. Cochrane 1979 Photograph: Cardiff University Library, Cochrane Archive, University Hospital Llandough

7 Impact of The Cochrane Library Guidelines Many guideline bodies insist on Cochrane evidence Health Care Funding Funding bodies will not fund health care without consulting Cochrane evidence Research Funding Research funding bodies consult Cochrane evidence before approving research funds Journal Editors Recently journal editors will insist on a SR evidence that an RCT is needed before accepting and RCT for publication

8 Speaking of Impact Impact on your academic career 2017 Impact factor = The CDSR is ranked 13 of the 155 journals in the Medicine, General & Internal category (Q1) (JIF percentile ) The Lancet Our work is recognized as representing an international gold standard for high quality, trusted information Single most reliable source of information about healthcare interventions

9 Wider Reaching Impact

10 Plain language summary Deworming drugs for treating soil transmitted intestinal worms in children: effects on nutrition and school performance The main soil transmitted worms are roundworms, hookworms, and whipworms. Infections are common in tropical and subtropical areas, particularly in children from low income areas where there is inadequate sanitation, overcrowding, low levels of education, and lack of access to health care. These infections sometimes cause malnutrition, poor growth, and anaemia in children, and some experts believe they cause poor performance at school. While improved

11

12

13

14

15

16

17

18 Cochrane Collaboration

19 Our vision is that healthcare decision making throughout the world will be informed by high quality, timely research evidence"

20 Our mission is to help people make well informed decisions about healthcare by preparing, maintaining & promoting the accessibility of systematic reviews of the effects of health care interventions

21 About us We believe in equal partnerships We have no geographical boundaries We are independent We are democratically led We advocate evidence based decision making We hold Official Relations with the WHO

22 International non profit organisation

23 Structure > 130 countries involving > 30,000 volunteers Decentralised structure Secretariat and Cochrane Editorial Unit (UK) 52 Cochrane Review Groups 8 network specific areas of health care Largely funded by government grants

24 Cochrane Malaysia Number of Malaysian authors: 3 to 426 (2002 to July 2017) Activities in Australasia and South East Asia coordinated by Cochrane Australia Coordinating site Penang Medical College (PMC) Prof Jacqueline Ho convenor Other network sites Universiti Sains Malaysia Melaka Manipal Medical College Institute for Medical Research University of Malaya

25 USM Cochrane Coordinating Centre 28/11/2017

26 Old way of solving clinical problems Clinical problem Observations Associations, Prognosis Basic mechanisms of disease Clinical Care Basic Research Physiology, Biochemistry, Pharmacology Oxygen therapy for preterm infants Sulphonamides for preterm infants Treatment of hyperbilirubinaemia Management of hypoglycaemia

27 Use of Evidence to Solve Clinical Problems Community Socio economic Audit, Quality Improvement Health Clinical problem Observational Associations, Prognosis Genetic / Environmental Ideas, Imagination, Innovation, Infrastructure, Basic mechanisms of disease Clinical Care Implementation of Research Patient preferences Clinical resources Basic Research Physiology, Biochemistry, Pharmacology, Immunology, Genetics, Bioinformatics, Neuroinformatics.. Effective treatments Diagnostic tests Guidelines Applied Research Clinical trials, comparative studies Systematic Reviews Potential treatments or Diagnostic tests Henderson Smart

28 + Level 1 Level 2 Level 3 Level 4 Level 5 Levels of Evidence (therapeutic & preventive) 1a) Systematic review of randomised trials 1b) Individual randomised trial 2a) Systematic review of cohort studies 2b) Individual cohort (& low quality RCT) 2c) Outcomes research 3a) Systematic review of case-control studies 3b) Individual case-control study Case series (& poor quality cohort & case-control studies) Expert opinion Bias +

29 Cochrane Systematic Reviews & Meta analyses

30 Systematic review A review of studies in which evidence has been systematically searched for studied assessed and summarized according to pre determined criteria.

31 Why systematic reviews? Efficient way to access the body of research saves time required for searching critical appraisal interpretation of results Explore differences between studies Reliable basis for decision making unbiased selection of relevant information useful for health care, policy, future research

32 Systematic Review Meta analysis Systematic reviews Metaanalyses optional part of a systematic review

33 What is a meta analysis? A statistical technique Estimates an average or common effect & expresses this quantitatively Combines the results from two or more studies

34 Why perform a meta analysis? Quantify treatment effects and their uncertainty Increase power Increase precision Explore differences between studies Settle controversies from conflicting studies Generate new hypotheses

35 When meta analysis is done? More than one study has estimated an outcome Each study address same question consider comparison and outcomes requires your subjective judgement There are no differences in the study characteristics that are likely to substantially affect the outcome The outcome has been measured in similar ways

36 Steps in a meta analysis 1. Identify comparisons to be made 2. Identify outcomes to be reported & statistics to be used 3. Collect data from each relevant study 4. Combine results to obtain the summary of effect 5. Explore differences between the studies 6. Interpret results

37 Selecting comparisons Hypothetical review: Caffeine for daytime drowsiness Break your topic down into pair wise comparisons caffeinated coffee vs decaffeinated coffee Each review may have one or many Use your judgement to decide what to group together & what should be a separate comparison

38 Selecting outcomes & effect measures Hypothetical review: Caffeine for daytime drowsiness caffeinated coffee vs decaffeinated coffee For each comparison, select outcomes Outcomes headaches (RR) asleep at end of trial (RR) irritability (MD/SMD) For each outcome, select an effect measure Depend on the available data from included studies odds ratio, relative risk, mean difference

39 Weighting studies More weight to the studies which give us more information More participants More events Lower variance Weight is proportional to inverse variance

40 For example Headache caffeinated coffee decaffeinated coffee Amore Coffea /31 10/34 Deliciozza /40 9/40 Mama Kaffa /53 9/61 Morrocona /15 1/17 Norscafe /68 9/64 Oohlahlazza /35 2/37 Piazza Allerta /35 6/37 Weight

41 For example Headache caffeinated coffee decaffeinated coffee Weight Amore Coffea /31 10/34 6.6% Deliciozza /40 9/ % Mama Kaffa /53 9/ % Morrocona /15 1/17 2.9% Norscafe /68 9/ % Oohlahlazza /35 2/37 5.1% Piazza Allerta /35 6/ %

42 Presenting your results A forest of lines Trees Joyce Kilmer Forest by charlescleonard

43 Headache at 24 hours Forest plots headings explain the comparison

44 Headache at 24 hours Forest plots list of included studies

45 Headache at 24 hours Forest plots raw data for each study

46 Headache at 24 hours Forest plots weight given each study

47 Headache at 24 hours Forest plots effect estimate for each study with CI

48 Headache at 24 hours Forest plots effect estimate for each study with CI

49 Headache at 24 hours Forest plots scale & direction of benefit

50 Headache at 24 hours Forest plots pooled effect estimate for all studies with CI

51 Cochrane Process

52 The Cochrane process Title Protocol Review Editorial process Define question Competence of author team PICO Plan search Describe methods Peer review Publish Undertake search Screen results Identify included studies Risk of bias of included studies Extract and analyse data Write up and submit Peer review Revision Copy edit Publish Updating

53 Revman software for preparation of protocol & reviews

54

55 Quality assurance

56 Cochrane Library

57 Cochrane Library

58 Search for subject of interest

59

60

61

62 Cochrane Translation

63 Why translate? magic.piktochart.com/output/ cochrane translations infographic

64

65 Cochrane: Bahasa Malaysia

66

67 Take home messages Systematic reviews & meta analyses are highest quality research evidence efficient way to access the body of research Cochrane reviews provides reliable information to support healthcare decisions

68

69

70 Thank you