An Introduction to Systematic ReviewsCharles J Greenberg, MLS, Med, AHIP Fulbright Specialist Project #5104 Yerevan, Armenia firstname.lastname@example.org email@example.com (203) 737-2960 Yale UniversityCushing/Whitney Medical Library
Session Outline What is a Systematic Review? How to locate existing Reviews Typical Steps in Conducting a Review How can a librarian help? Guides and Sources
What is a Systematic Review? A systematic review attempts to identify, appraise and synthesize all the empirical evidence that meets pre-specified eligibility criteria to answer a given research question. Researchers conducting systematic reviews use explicit methods aimed at minimizing bias, in order to produce more reliable findings that can be used to inform decision making. Definition Source: Cochrane Collaboration
Why are systematic reviews important? In the Evidence Pyramid, systematic reviews represent qualitative value for published research. Note the pyramid suggests that fewer are created.
A PubMed@Yale Clinical Queries Search canfind published systematic reviews
The Cochrane Library a library subscription collection of databases that contain different types of high-quality, independent evidence. Cochrane Database of Systematic Reviews (CDSR) CDSR is the most recognized database. Other databases include a register of controlled clinical trials, a research methodology register, technonolgy assessment, evaluation studies, etc.
Before you begin…. Is a systematic review necessary? Does one already exist? Consider the level of commitment and follow through that is necessary Do you have a team or partners? Can you recruit colleagues? Do you have library support? ( I will address what the library can do later)
1st Step- Define the Question •Framing the question in a way which lends itself to searching •PICO: The situation or population, the intervention, comparison (if appropriate; may be implied) and the desired outcome. P: patients arrive with acute low back pain I: warm or heat C: [cold or nothing] O: Pain Relief Answerable Question: In patients with low back pain, is heat an effective therapy for pain relief?
Check to see if one or more systematicreviews already exist for your question If you dont have a HINARI password or dont want to log in, you can view Cochrane Library, The as a member of the public. You will not have full access, unless your institution participates in other arrangements. Click here to proceed to Cochrane Library, The without logging in.
Confirm subject of review, basedyour formulated question. •The problem should be specified in a clear, unambiguous and structured question before beginning the review work. •Once the review question has been set, only modify if alternative ways of defining the populations, interventions, outcomes or study designs produce a new question.
Produce all the specifications (details)to define the review protocol •Conceptual discussion •Confirm research question •Establish Search Strategy •Study Inclusion and exclusion criteria •Qualitative standard for assessment •Data extraction procedure • Data synthesis procedure •Record keeping •Project timetable PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses http://www.prisma-statement.org/
2nd step : Conduct a thoroughsearch, considering these sources •Cochrane Controlled Trials Register(CCTR) •Electronic databases •Trial registries not covered by CCTR •Citation lists from retrieved articles •Hand searching of key journals •Pharmaceutical companies •Personal communication with experts in the field
3rd step : Select the studies thatare relevant to the protocol •Review the titles and abstracts as a first pass, then obtain full text Have more than one reviewer check each article for initial eligibility, based on the agreed criteria. Develop a strategy to deal with disagreements. Keep a log of excluded studies, with reasons for study exclusion.
4th step : Appraise the quality of studieswith established qualitative labels (1) Example of qualitative labels: Cochrane Levels of study quality level I: systematic review of well-designed randomized controlled trials level II: randomized controlled trials level III: non-randomized clinical trials level IV: well-designed non-experimental studies level V: opinions of respected authorities, based upon clinical evidence, descriptive studies, or reports of expert committees level VI: someones opinion
4th step : Appraise the quality of studieswith the established qualitative labels (2) Consider quality assessment by more than one reviewer Use a simple scale or checklist, like Cochrane levels (previous slide example) Assess for quality factors or their concealment, like treatment allocation, blinding, and handling of patient attrition Consider blinding your reviewers to authors, institutions, and journals.
5th Step: Extracting data fromstudies • Design and pilot a data extraction form • Consider data extraction by multiple reviewers (if method is sound, same result) •Consider blinding extractors to author, institutions, and journal identities (eliminate bias in extraction)
6th Step: Analyze and present results Tabulate studies and examine composite view Consider sources of heterogeneity (were the studies selected too dissimilar?) Consider meta-analysis of all clinical trials Consider sensitivity analysis (Is there common strength and relevance?) Make a list of excluded studies that could be shared with explanation
What Can a Librarian Help with? • As an expert searcher, a librarian can interact with investigators to develop the search terms required for a comprehensive search strategy in multiple appropriate sources. This includes recommending overlooked resources. •This involves meeting with designated members of the team, or at times the whole team.
What Can a Librarian Help with? •As an organizer and analyzer, the librarian can effectively manage the articles and document the search, retrieval, and archival processes. •Accurate methodology documentation is required in a systematic review. •Maintain a record of search strategies •Re-run the strategies to identify new research within scope. •The research team will determine validity and applicability of new emerging research.
What Can a Librarian Help with? •The Librarian can also: •Recommend learning materials for doing systematic reviews •Obtain and organize access to full text for the team. •Update records, if asked and appropriate. •Write up details of the full search and methodology of obtaining and excluding studies
Thank You for your Time and Attention Charlie Greenberg