While both systematic and structured literature reviews aim to synthesize existing research, they differ in their rigor and methodology.
Systematic Literature Review
A systematic literature review is a highly structured and comprehensive process for identifying, evaluating, and synthesizing all relevant research on a specific topic. It follows a predefined protocol, ensuring transparency, replicability, and minimal bias.
Key characteristics:
- Explicit search strategy: Uses a predefined search strategy to identify all relevant studies.
- Rigorous inclusion and exclusion criteria: Clearly defined criteria for selecting studies based on specific research questions.
- Systematic data extraction: Uses standardized forms to extract data from included studies.
- Critical appraisal of studies: Assesses the quality of included studies using validated tools.
- Synthesis of findings: Summarizes and analyzes the findings of included studies, drawing conclusions based on the evidence.
Example: A systematic literature review examining the effectiveness of a new drug treatment for a specific disease might include:
- Search strategy: Using keywords and databases like PubMed and Cochrane Library.
- Inclusion criteria: Studies that are randomized controlled trials, published in English, and conducted on adult patients.
- Data extraction: Extracting information on study design, participant characteristics, intervention, and outcome measures.
- Critical appraisal: Assessing the risk of bias using tools like the Cochrane Risk of Bias tool.
- Synthesis: Summarizing the findings of individual studies and calculating a pooled effect size to assess the overall effectiveness of the drug treatment.
Structured Literature Review
A structured literature review is a more flexible approach that aims to provide a comprehensive overview of the literature on a specific topic. It follows a predefined structure but may not be as rigorous as a systematic review.
Key characteristics:
- Less strict search strategy: May use a less comprehensive search strategy compared to systematic reviews.
- Broader inclusion criteria: May include a wider range of study types and sources.
- Less formal data extraction: May use less standardized methods for extracting data.
- Less rigorous critical appraisal: May not use validated tools for assessing the quality of studies.
- Descriptive synthesis: Summarizes and analyzes the findings of included studies but may not draw formal conclusions.
Example: A structured literature review exploring the social determinants of health might include:
- Search strategy: Using a combination of keywords and databases.
- Inclusion criteria: Studies that examine social factors influencing health, published in peer-reviewed journals.
- Data extraction: Summarizing key findings and themes from included studies.
- Critical appraisal: Assessing the quality of studies based on general criteria.
- Synthesis: Describing the main themes and trends identified in the literature, providing a comprehensive overview of the topic.
Summary
The key difference between systematic and structured literature reviews lies in their level of rigor and methodology. Systematic reviews are more comprehensive and rigorous, using predefined protocols to ensure transparency, replicability, and minimal bias. Structured reviews are more flexible, offering a broader overview of the literature without the same level of rigor. The choice between the two depends on the specific research question and the desired level of evidence synthesis.
