It is a summary of the clinical literature and a critical assessment and evaluation of all research studies that address a particular clinical issue.

 The researchers use an organized method of locating, assembling, and evaluating a body of literature on a particular topic using a set of specific criteria to include / exclude studies

A systematic review typically includes a description of the findings of the collection of research studies, also include a quantitative pooling of data, called a meta-analysis.

1. Framing questions for a review:

   Questions should be clear, unambiguous and structured before beginning the review work . The PICO model is a useful framework to break down the research question for a systematic review.

2. Identifying relevant work:

   The search for studies should be extensive to capture as many relevant citations as possible, a wide range of medical, environmental and scientific databases were to identify primary studies. And developing a  protocol is extremely important in systematic reviews. The protocol specifies the methods to be used in the review with the aim of minimizing bias.

   The protocol needs to include the following elements:

   1. Inclusion/exclusion criteria

   1. Searching strategy

   2. Study selection criteria and process

   3. Data extraction process

   4. Assessment of study quality process

   5. Data synthesis method(s)

   6. Result dissemination plans

3. Assessing the quality of studies:

   Study quality assessment is relevant to every step of a review. Selected studies should be subjected to a more refined quality assessment by use of general critical appraisal guides and design-based quality checklists.

4. Summarizing the evidence:

   After finalizing the included studies, use a data extraction to extract all relevant data from each study then analyze and synthesize the results

   Extract data

   • the data and check for mismatches

   • Record data exactly as reported

   Analyse Data

   • The analysis will depend on the type of data extracted

   • Meta-analysis involves using of statistical methods to summarize the results of the chosen studies

   Perform a meta-analysis of the results will help improve the quality of the review and the conclusions

5. Interpreting the findings:

   1. Clearly present your findings:

      1. Include detailed methodology based on your protocol (search strategies used, selection criteria, etc.)

      2. This ensures that your review can be easily updated in the future with new research findings

   2. Propose future steps:

      1. Provide recommendations for practice and policy-making if sufficient, high quality evidence exists.

      2. Indicate future directions for research to fill existing gaps in knowledge or to strengthen the body of evidence.