Evidence Based Practice (EBP)

Riphah College of Rehabilitation Sciences(RCRS)Riphah International University Islamabad

Lecture topic

Understand the various methodologies for preparing a systematic review

Meta-Analysis The Role of Cochrane Collaboration in EBP Understand Narrative Reviews

What is systematic review?

A systematic review is a summary of the medical literature that uses explicit methods to perform a thorough literature search and critical appraisal of individual studies and that uses appropriate statistical techniques to combine these valid studies

Various Methodologies

Methodology presented by National Health Service Centre for Reviews and Dissemination (University of Yark-2001)

Methodology presented by British national Health Service’s Systematic Reviews (University of Leicester)

Methodology from the Cochrane Collaboration. Methodology by Greenhalgh Methodology by Lau et al.

Methodology presented by university of Yark-2001

Planning the review (Phases 0-2) Conducting the review (Phases 3-7) Reporting and dissemination (Phases 8-9)

Planning the Review

Phase 0;Identification of the need for the review

Phase 1; Preparation of a proposal for a systematic Review

Phase 2; Development of a review protocol

Conducting the Review

Phase-3; Identification of the literature Phase-4; Selection of studies Phase-5; Study quality assessment Phase-6; Data extraction and monitoring

progress Phase-7;Data Synthesis

Reporting and Dissemination

Phase-8; The report and recommendation Phase-9; Getting evidence into practice

Methodology presented by University of Leicester1. Compile thoroughly systematic review methods of as comprehensive a set

as possible of reports of relevant studies.

2. Identify a common set of definitions of outcomes,explanatory,and confounding variables, which are as far as possible, compatible with those in each of the primary studies.

3. Extract estimate of outcome measures and of study and subject characteristics in a standardized way and with due checks on extractor bias.

4. Where warranted by the scope and characteristics of the data compiled,meta-analysis using methods and modals appropriate to explore and allow for all important sources of variation.

5. Explore the sensitivity of the results of the meta-analysis to the choices and assumption made in all of the above stages.

6. Present key aspects of all of above stages in the study report clearly.

Methodology from the Cochrane Collaboration

1. Conceiving, designing, and coordinating the review

2. Data Collection for the review3. Developing, search strategy, undertaking

searches, screening search results.4. Screening retrieved papers against inclusion

criteria, appraising quality of papers5. Abstracting data from papers6. Analysis and interpretation of data7. Writing the review

Methodology by Greenhalgh

1. State objectives of the review of RCT and outline eligibility Criteria

2. Search for trails that seem to meet eligibility criteria

3. Tabulate characteristics of each trail identified and assess its methodological quality

4. Apply eligibility criteria and justify any exclusions

5. Assemble the most complete data set feasible with assistance from investigators, if possible

6. Analyze results of eligible RCTs using statistical synthesis of data if appropriate and possible

7. Compare alternative analysis if appropriate and possible

8. Prepare a critical summary of the review, stating aims describing materials and methods, and reporting results.

Methodology by Lau et al(1997) Define and decide on what data is to be

combined Evaluate the statistical heterogeneity of

data Estimate a common effect Explore and explain heterogeneity Assess the potential for bias Present the results

Meta-Analysis

A Meta-Analysis combines the results of several studies that address a set of related research hypotheses.

“Meta-Analysis is a name that is given to any review article in which the results of several independent studies are combined statistically to produce a single estimate of the effect of a particular intervention or health care situation”.(Dr.Alejandro Jadad-1998)

Question:What is the difference between a "systematic review" and a "meta-analysis"?

Answer: A systematic review is a thorough, comprehensive, and

explicit way of interrogating the medical literature. It typically involves several steps, including;

(1) asking an answerable question (2) Identifying one or more databases to search(3) Developing an explicit search strategy(4) Selecting titles, abstracts, and manuscripts based on explicit

inclusion and exclusion criteria(5) Abstracting data in a standardized format.

A "meta-analysis" is a statistical approach to combine the data derived from a systematic-review. Therefore, every meta-analysis should be based on an underlying systematic review, but not every systematic review leads to a meta-analysis.

Cochrane Collaboration

The Cochrane Collaboration is a group of over 11,500 volunteers in more than 90 countries who apply a rigorous, systematic process to review the effects of interventions tested in biomedical RCTs.

The Cochrane Collaboration was founded in 1993 under the leadership of Iain Chalmers, It was developed in response to Archie Cochrane's call for up-to-date, systematic reviews of all relevant RCTs of health care.

Goal

The goal is to help people make well informed decisions about health care by preparing, maintaining and ensuring the accessibility of systematic reviews of the effects of health care interventions

The principles of the Cochrane Collaboration collaboration building on the enthusiasm of individuals avoiding duplication minimizing bias keeping up to date striving for relevance promoting access ensuring quality continuity enabling wide participation

Cochrane Library

The Cochrane Library is a collection of databases in medicine and other healthcare specialties provided by the Cochrane Collaboration.

At its core is a database of systematic reviews and meta-analyses which summaries and interpret the results of high-quality medical research.

The Cochrane Library aims to make the results of well-conducted controlled trials readily available.

It is a key resource in evidence-based medicine.

Cochrane Databases

The Cochrane Database of Systemic Reviews (Cochrane Reviews)

The Database of Abstracts of Reviews of Effects (DARE) The Cochrane Central Register of Controlled Trials

(CENTRAL) The Cochrane Database of Methodology Reviews

(Methodology Reviews) The Cochrane Methodology Register (Methodology

Register) Health Technology Assessment Database (HTA) NHS Economic Evaluation Database (NHS EED)

Narrative review

Subjective and may be biased No explicit methods for searching literature or

reporting and report results of results Cannot be replicated Often broad in scope Often a qualitative summary