|Year : 2015 | Volume
| Issue : 2 | Page : 63-64
Cochrane systematic review protocols
Jayant N Palaskar
Editor-in-Chief, Journal of Dental and Allied Sciences, Sinhgad Dental College and Hospital, Pune, Maharashtra, India
|Date of Web Publication||11-Dec-2015|
Jayant N Palaskar
Professor and Head, Department of Prosthodontics, Sinhgad Dental College and Hospital, Pune - 411041, Maharashtra
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Palaskar JN. Cochrane systematic review protocols. J Dent Allied Sci 2015;4:63-4
Systematic reviews, as the name implies, typically involve a detailed and comprehensive plan and search strategy derived a priori, with the goal of reducing bias by identifying, appraising, and synthesizing all relevant studies on a particular topic.  A protocol is a plan or set of steps to be followed in a study. A protocol for a systematic review should describe the rationale for the review; the objectives; and the methods that will be used to locate, select and critically appraise studies, and to collect and analyze data from the included studies.  The Cochrane system requires a particular protocol to be followed for a review to be included in Cochrane database, only upon its inclusion it will be called as "Cochrane review." The Cochrane Database of Systematic Reviews is composed of modules of reviews submitted by Collaborative Review Groups registered with The Cochrane Collaboration.  There are around 53 such groups for medical sciences which include various medical subjects such as infectious diseases group, common mental disorders group, ENT group, skin group, and many more. The Cochrane database maintains around 9000 systematic review articles from medical sciences.
Out of 53 review groups, one of the groups specialized for oral health care is the Cochrane Oral Health Group (OHG) that maintains around 215 reviews (as of date). The Cochrane OHG comprises an international network of healthcare professionals, researchers, and consumers preparing, maintaining, and disseminating systematic reviews of studies in oral health.  Oral health is broadly conceived to include the prevention, treatment, and rehabilitation of oral, dental, and craniofacial diseases and disorders. 
For any dental Cochrane review to be conducted, the very first step is to register the research title and get it approved from Cochrane OHG. Initial title approval is mandatory to avoid repetition of the review topic. Cochrane collaboration encourages interventional reviews which are of great clinical significance and useful for clinicians to make informed decisions for treatment of patients.
The following step by step protocol is given for the benefit of our readers as a blueprint for conducting a Cochrane systematic review. Interested readers are encouraged to access the latest edition of Cochrane Handbook for Systematic Reviews.
The steps in a systematic review: 
- Step 1: Framing questions for a review.
The problems to be addressed by the review should be specified in the form of clear, unambiguous, and structured questions before beginning the review work. Once the review questions have been set, modifications to the protocol should be allowed only if alternative ways of defining the populations, interventions, outcomes, or study designs become apparent.
- Step 2: Identifying relevant work.
The search for studies should be extensive. Multiple resources (both computerized and printed) should be searched without language restrictions. The study selection criteria should flow directly from the review questions and be specified a priori. Reasons for inclusion and exclusion should be recorded.
- Step 3: Assessing the quality of studies.
Study quality assessment is relevant to every step of a review. Question formulation (Step 1) and study selection criteria (Step 2) should describe the minimum acceptable level of design. Selected studies should be subjected to a more refined quality assessment by the use of general critical appraisal guides and design-based quality checklists (Step 3). These detailed quality assessments will be used for exploring heterogeneity and informing decisions regarding the suitability of meta-analysis (Step 4). In addition, they help in assessing the strength of inferences and making recommendations for future research (Step 5).
- Step 4: Summarizing the evidence.
Data synthesis consists of a tabulation of study characteristics, quality, and effects as well as the use of statistical methods for exploring differences between studies and combining their effects (meta-analysis). Exploration of heterogeneity and its sources should be planned in advance (Step 3). If an overall meta-analysis cannot be done, subgroup meta-analysis may be feasible.
- Step 5: Interpreting the findings.
The issues highlighted in each of the four steps above should be met. The risk of publication bias and related biases should be explored. Exploration for heterogeneity should help determine whether the overall summary can be trusted, and, if not, the effects observed in high-quality studies should be used for generating inferences. Any recommendations should be graded by reference to the strengths and weaknesses of the evidence.
The aim of this editorial is to give a bird's eye view of the Cochrane review process. Although the intricacies and efforts needed for this type of review are stupendous, it is hoped that through this editorial, many academicians and practitioners will get encouraged to include "Cochrane review" in their future research projects.
| References|| |
Higgins JP, Green S, editors. Cochrane Handbook for Systematic Reviews of Interventions. Ver. 5.1.0. The Cochrane Collaboration; 2011. Available from: http://www.cochrane-handbook.org
. [Last updated in March 2011].
Khan KS, Kunz R, Kleijnen J, Antes G. Five steps to conducting a systematic review. J R Soc Med 2003;96:118-21.
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