Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
How to read a Cochrane review.
The Basics.
Jan Hoving, Regina Kunz, Emilie Friberg, Frederieke Schaafsma
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Workshop - How to read a Cochrane review
This workshop:
- Workshop setup: ‘question and answer’ format
- Material: a. Published Cochrane Review (van Vilsteren, short version)
b. Question sheet
What are we going to do?
1. Read summary of Cochrane review (10 min)
2. Read questions and discuss answer with neighbor (20 min)
3. Plenary discussion using input participants + additional
explanation presenters (60 min)
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
What is the Cochrane Collaboration?
The Cochrane Collaboration
• Organisation
• global network of 90 entities such as review groups
• involves about 30.000 volunteers all over the world
• 60 paid staff in Cochrane Central Executive London UK
• no central funding for reviews
• Mission
• provide up to date evidence on the effects of health care
• Name
• after Archie Cochrane, British epidemiologist
• Web address
• www.cochrane.org
• Products
• High quality systematic reviews of healthcare interventions
• Collated in the Cochrane Library, Impact Factor 6.2
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
• International network, not for profit, collaborative
• Infrastructure and rules
• Aims for high quality evidence and transparency
• Established methodology
• Tool for disseminating reviews: The Cochrane Library
• Registry for primary studies: CENTRAL
• Applicable knowledge useful to stakeholders
• Non-exclusive: everybody with the necessary skills can contribute
• Contribute to work attractiveness and professional pride
What is the Cochrane Collaboration?
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
• Contact with users in the insurance setting
• Advocates for IM research and systematic reviews to be
integrated in IM decisions and judgements, showing gaps and
possible bridges
• Identifies and tags Cochrane reviews related to IM
• Lobbies for the development of registries for IM evidence
• Provides education to IM practitioners, and other stakeholders
about evidence-based insurance medicine and Cochrane
reviews and how to use them in practice
What is Cochrane Insurance Medicine?
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Question 1: Terminology: What is a ‘review’? What a ‘systematic
review’? What is a ‘Cochrane systematic review’?
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Search for aggregated evidence if available
Cochrane
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
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Cochrane Review Production Process
• Title registration with a review group
• Protocol
– background, search, methods
– peer-reviewed
– publication in Cochrane Library
• Review
– peer-reviewed (editors and external experts)
– according to Cochrane Handbook
– published in Cochrane Library
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
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Typical structure of a Cochrane Review• Title
• Background
• Methods
– Inclusion criteria
– Search
– Data Synthesis
• Results
– Description of included studies
– Risk of bias
– Effects of interventions
• comparisons
• outcome data
• pooling
– forest plot
• Discussion
• Conclusions
– implications for practice
– implications for research
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Question 2: How do I find a Cochrane review ? Do I need special
access?
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Most common health-related questions by insurance physicians?
Kok et al:
• Prognostic questions 39%
• Intervention questions 26%
• Etiologic or diagnostic questions 17%
Cochrane Library !
Question 2: How do I find a Cochrane review? Do I need special
access?
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Question 2: How do I find a Cochrane review ? Do I need special
access?
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Question 2: How do I find a Cochrane review? The Cochrane
Library
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Question 2: How do I find a Cochrane review? The Cochrane
Library
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Question 3: What is the PICO in the van Vilsteren review?
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Question 3: What is the PICO in the van Vilsteren review?
“In patients with disease P, does therapy I work better than
therapy C in improving outcome O”?
• Patient:
• Intervention:
• Control:
• Outcome:
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Question 4: What are the key steps in a Cochrane systematic
review?
Think about the different steps, you would expect in a Cochrane
review.
It may help to refer to the short version of the van Vilsteren review
(hand-out)
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Question 4: What are the key steps in a Cochrane systematic
review?
1. Well-formulated question (PICO)
2. Thorough search
3. Objective selection of studies
4. Critical assessment of the methodological quality
5. Objective data extraction
6. Summary of the data (descriptive or statistical summary)
7. Conclusions for practice and research
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Question 5a): Which databases did reviewers use to search for
the studies? b) What type of studies did van Vilsteren include?
Check the databases searched by the authors?
Inclusion/exclusion criteria, with regards to the
• Type of studies
• Type of participants
• Type of interventions
• Type of outcomes
Type of studies … RCT: randomised controlled trial ?
PopulationIn- en exclusion
criteria
Intervention group
Control group
randomise
RTW yes
RTW no
RTW yes
RTW no
Blinding
Question 6: What is risk of bias? Other features that determine
quality?
• Randomised trials start at high quality but downgraded when
• limitations in study design: high risk of bias
• inconsistency of results
• indirectness of evidence
• imprecision of estimates (wide confidence intervals)
• publication bias
Question 6: What is risk of bias? Other features that determine
quality?
• Randomised trials start at high quality but downgraded when
• limitations in study design: high risk of bias
• inconsistency of results
• indirectness of evidence
• imprecision of the estimate (wide confidence intervals)
• publication bias
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Question 6: What is risk of bias? Other features that determine
quality?
Imprecision of the estimate
Question 7: How did the reviewers define “overall quality of the
evidence”
Overall judgement of quality of evidence of all studies in a systematic review:
high, moderate, low or very low
Description Definition
High quality Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality Any estimate of effect is very uncertain.
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Question 8: How do I read and understand a forest plot?
see figure 3
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
Question 9: What is your conclusion from the evidence of this
Cochrane systematic review?
Research Center for Insurance Medicine: collaboration between AMC-UMCG-UWV-VUmc
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