1. Defining the Research Question:
* Formulate a clear, focused, and answerable research question. This often uses the PICO (Population, Intervention, Comparison, Outcome) framework or similar structured approaches (e.g., SPIDER for qualitative reviews). The question should specify the population of interest, the intervention or exposure being studied, the comparison group (if applicable), and the outcome(s) of interest.
* Develop inclusion and exclusion criteria. This precisely defines which studies will be included and excluded based on factors like study design, population characteristics, intervention types, and outcome measures. These criteria should be explicit and justified.
2. Searching for Studies:
* Identify relevant databases. This involves selecting appropriate electronic databases (e.g., PubMed, Embase, Cochrane Library, Web of Science) and potentially grey literature sources (e.g., dissertations, conference proceedings, government reports).
* Develop a comprehensive search strategy. This includes a detailed list of keywords, MeSH terms (Medical Subject Headings), and search strings tailored to each database. The strategy should be documented and reproducible.
* Conduct the search and document the process. Record the databases used, search strings, dates of the search, and any limitations encountered.
3. Study Selection:
* Screen titles and abstracts. Independently screen titles and abstracts of identified studies to determine their relevance based on the inclusion and exclusion criteria.
* Screen full-text articles. Obtain full-text articles of potentially relevant studies and independently assess them against the inclusion/exclusion criteria.
* Resolve disagreements. If discrepancies arise between reviewers, establish a process for resolving them (e.g., discussion with a third reviewer, consensus-based decision).
4. Data Extraction:
* Develop a data extraction form. Create a standardized form to systematically collect relevant information from each included study. This might include study characteristics (e.g., sample size, study design, year of publication), participant characteristics, intervention details, and outcome measures.
* Extract data. Independently extract data from included studies using the data extraction form. This should be done by at least two reviewers to ensure accuracy and minimize bias.
* Resolve disagreements. Establish a process for resolving discrepancies in extracted data.
5. Quality Assessment:
* Select appropriate quality assessment tools. Choose validated tools relevant to the study designs included in the review. These tools assess the risk of bias within individual studies.
* Assess the quality of included studies. Independently assess the quality of each included study using the chosen tools. This helps to evaluate the trustworthiness of the evidence.
* Assess the risk of bias across studies. This involves considering potential biases inherent in the methods and reporting of the studies.
6. Data Synthesis and Analysis:
* Analyze the extracted data. Synthesize the data extracted from included studies, using appropriate methods depending on the nature of the data (e.g., meta-analysis for quantitative data, thematic analysis for qualitative data).
* Present the findings. Clearly present the results of the data synthesis, including summaries of study characteristics, quality assessments, and findings from the analysis. This is crucial for transparency and replicability.
7. Interpretation and Reporting:
* Interpret the findings in the context of the research question and existing literature. Discuss the implications of the findings, limitations of the review, and areas for future research.
* Prepare a systematic review report. Write a comprehensive report following established guidelines (e.g., PRISMA statement for systematic reviews and meta-analyses). The report should include all steps of the review process, including the search strategy, study selection, data extraction, quality assessment, and data synthesis.
Following these steps systematically ensures a rigorous and reliable evaluation of existing literature. Remember that the specific methods employed within each step might vary depending on the research question and type of studies included. Consult guidelines like PRISMA and Cochrane Handbook for more detailed information.