Systematic Reviews: the researcher's perspective and the research question. Edoardo Aromataris
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Transcript of Systematic Reviews: the researcher's perspective and the research question. Edoardo Aromataris
www.joannabriggs.edu.au
Systematic reviews: the researcher’s perspective and the
research question
Edoardo Aromataris
www.joannabriggs.edu.au
Questions for you• Where do you work? What settings?
– Health care? Hospital, University, government health service?
• Who’s had some experience with systematic reviews?– Was it...pleasant?
• What is a systematic review?
www.joannabriggs.edu.au
Researcher’s perspective• The review question• What do we know?• What should we know?
– PICO/PICo• Depends on who we are...• Interaction between researchers and librarians• What to expect from us
www.joannabriggs.edu.au
Steps in a Systematic Review• Formulate review question• Define inclusion and exclusion criteria• Locate studies• Select studies• Assess study quality• Extract data• Analysis/summary and synthesis of relevant studies• Present results• Interpret results/determining the applicability of results
(Egger & Davey Smith, 2001:25; Glasziou et al., 2004:2)
www.joannabriggs.edu.au
Question Development
• Aim is to provide a framework for the development and conduct of the review
• A good question supports the review, a poor question risks confounding the review
• A good question responds to identified priorities and needs
www.joannabriggs.edu.au
Question Development
• Reviews of effects & economics:– Population– Intervention/Exposure– Comparator– Outcome– Types of Study Design
• Reviews of qualitative & Textual data:– Population– Phenomena of Interest– Context
Divide question following the PICO/PICo model
www.joannabriggs.edu.au
Questions of the effects of interventions• Population:
–The most important characteristics, including:• demographic factors of the population (e.g. age,
gender, ethnicity) • socioeconomic factors• the setting (e.g. hospital, community etc)• illness
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Questions of the effects of interventions
• Intervention and Comparator–Primary intervention of interest (treatment group)–Comparator (control group)
• Passive (placebo, no treatment, standard care, or a waiting list control)
• Active (variation of the intervention, a drug, or kind of therapy)
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Questions of the effects of interventions• Outcomes
– Identify the primary outcome/s in order to reach a clinically relevant conclusion
– Secondary outcomes may be required– Avoid use of surrogate outcomes unless clearly
reasoned in the background– Consider how the type and timing of outcome
measurements impacts on outcome measurement
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Example
• Are antiseptic washes more effective than non-antiseptic washes at preventing nosocomial infections in patients undergoing surgery?
intervention comparison
outcome population
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Example
• Are antiseptic washes more effective than non-antiseptic washes at preventing nosocomial infections in patients undergoing surgery?
intervention comparison
outcome population
http://guides.library.upenn.edu/content.php?pid=192036&sid=1610308
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Questions of the experiential evidence• Qualitative and textual reviews:
– Re-focus to phenomena of Interest, not intervention, – and Context not comparator
• The phenomena of Interest relates to a defined event, activity, experience or process
• Context is the setting or distinct characteristics
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Example
• What are caregivers experiences of providing home-based care to persons with HIV/AIDS in Africa?
Phenomena ofinterest
population
Context
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Example
• What are caregivers experiences of providing home-based care to persons with HIV/AIDS in Africa?
Phenomena ofinterest
population
Context
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PICO / PICo
• Constructing a well-built clinical question is a fundamental skill
• Question should be arranged following the PICO/PICo model
• The question operationalises the review by forming the basis for inclusion and exclusion criteria and the search strategy
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Inclusion Criteria: Effects• Draws upon:
– Population characteristics– Intervention or exposure– Comparator - active or passive– Outcomes of interest
• Study type and other elements of the review such as language, year of publication etc
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Inclusion Criteria: Experience
• Draws upon: – Population characteristics– Phenomena of Interest– Context
• Study type and other elements of the review such as language, year of publication etc
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Different questions lead to different evidence• Effectiveness of therapy• Adverse events and harmful outcomes of therapy• Aetiology of disease• Diagnosis and diagnostic test accuracy• Prognosis
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Focused versus broad question• Does SSRI antidepressant increase the risk of suicide in
teenagers?– Clear guide to the data the reviewer will look for and will arrive at
clear conclusions. – Identified outcome - miss full safety profile of drug
• What are common adverse events when starting on antidepressant therapy?– Find new events across a range of drugs– Vast amounts of heterogeneous data difficult to synthesise and
draw conclusions from.
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Broader question?• Is a systematic review appropriate?
– ‘What smoking cessation interventions (population level) does the published evidence suggest are effective and represent ‘value for money’?
– ‘What are the main risks to patient safety in primary care?’
• Consider a scoping review
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Question Development
• Verify that the question has not already been addressed – Search protocols and systematic review reports in the
JBI and Cochrane Libraries and others• May be similar topic – shouldn’t be the same
question unless justification is provided– Critically appraise and assess quality of review
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Protocol• Guide process
– Reasoned approach to the question asked• Detailed review methods a priori• Decrease biased post hoc changes”• Main details are question, eligibility or inclusion
criteria, approach to search and remainder of steps
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Review Team• Funder• Content experts, researchers• Methodologists with experience in systematic
reviews• Statistician • Librarian• End users - policy makers/decision makers
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Researchers and Systematic Reviews
• Types/breeds of researchers– Academic/expert in their field– Consultant– Clinician– Student/novice
• Not always mutually exclusive• Experience?
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Breeds...• Academic
– Know the topic, do they know the method?• Consultant
– May know it all, may know nothing, or somewhere in between...– Still have some grounding in research and what its all about– Methodologist advantage
• Clinician– Know the need/questions– Not how to approach the research
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PICO / PICo
• Constructing a well-built clinical question is a fundamental skill
• Divide question following the PICO/PICo model
• The question also forms the basis for the search strategy– PICO concepts
From PICO to search• Nursing management of cancer fatigue in patients• Concept map
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Researcher's knowledge• Led from the question through PICO....• ...define eligibility criteria....• ...into an example search strategy...• ....told where they can search...
• Onto the next step
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Knock, Knock....• ...who’s there?
– Academic/methodologist/clinician– Experience with systematic reviews?
• Not everyone understands what a systematic review is!
• Who are they and where are they coming from?• The question....what is it?
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What’s the question...?• What concepts?
– Same words - different definitions and meanings– Different words – same definitions and meanings
• Not everyone comes armed with their own question– Contract/consultancy– Researcher may be the middle man
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Researchers may fail to appreciate...• Search is incredibly important part of the review
process• No evidence = no review• How and where are some of the defining features of
the review process• Will understand ‘reproducibility’
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Researcher’s question• “...major difficulty being able to conceptualise their
question...”• “...can’t describe what they’re trying to do...”
• You may be left to (help) interpret aims of the project!
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Search strategy• “...no capacity to be logical...”• “..logic grid doesn’t reflect what she’s trying to do...”• “...its not rocket science...”• “...essential elements are language and logic...”
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Search strategy• Many researchers understand PICO, they just fail to
follow it• Many questions wont have all of the elements of a
PICO question• Maybe different elements
– Settings, study design, aspects of population/intervention
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Search Strategy• Strategy is more important than the search itself and
requires a great deal more time– Results driven researcher
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Databases• Fail• No idea• “...I’m going to do a search of OVID....”• Search “PubMed and OVID Medline...”
• How much to explain?
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...works both ways...• Can’t do the experiment unless you understand the
tools you’re working with
• Researchers and reviewers are told to refer to the librarian
• Need to understand the nature of the work and maybe even the topic
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Summary• Question• PICO and conceptualising a question• Researchers come in all shapes and sizes• Search
– Critical for review success• Many will not understand what you do, why you do it
and the impact it will have on their systematic review!