What Is a Systematic Review? A Guide to Scientific Research

What is a systematic review in scientific research?Systematic review plays a pivotal role in scientific research, serving as an effective tool for collecting, evaluating, and analyzing available scientific evidence on a specific topic in a systematic and organized manner. These reviews are widely used in various fields such as medicine, education, and social sciences to provide reliable insights based on scientific evidence, thereby improving the quality of research decisions and recommendations.

Systematic review relies on precise methods and clear steps that include defining the research question, searching reliable scientific sources, selecting relevant studies according to specific criteria, and then critically analyzing them to draw applicable conclusions. This approach helps reduce bias and achieve maximum accuracy and reliability in interpreting scientific results.

In this article, we will explore in detail the concept of systematic review, its importance, types, and the essential steps for conducting it successfully, as well as the challenges researchers face during its implementation and how to overcome them to achieve the best possible results.

What Is a Systematic Review in Scientific Research?

Systematic review (Systematic Review) is one of the most important tools inscientific research, aiming to collect, evaluate, and summarize all available evidence around a specific research question using an organized and precise methodology. These reviews are widely used in medical, social, and educational fields to support evidence-based decision making.

Concept of Systematic Review

Systematic review is a type of study that combines results from multiple research on a particular topic, with the aim of providing a comprehensive summary of available evidence. These reviews follow strict systematic steps to ensure transparency and accuracy in data collection and analysis.

Characteristics of Systematic Review and Its Importance in Scientific Research

Systematic review is characterized by the following features:

• Systematic approach:Follows specific clear steps for data collection and analysis.
• Comprehensiveness:Aims to include all studies relevant to the topic.
• Bias reduction:Uses specific criteria for selecting and evaluating studies to reduce bias.
• Reproducibility:Other researchers can replicate the review by following the same methodology.

Difference Between Systematic Review and Traditional Review

While traditional review relies on an unstructured literature review, systematic review follows a rigorous methodology that includes:

• Defining a clear research question.
• Using specific criteria for selecting studies.
• Evaluating the quality of included studies.
• Analyzing and summarizing results using statistical or qualitative methods.

Objectives of Systematic Review in Scientific Research

Systematic review aims to achieve several objectives, including:

• Providing a comprehensive summary of available evidence:Through collecting and analyzing results from various studies.
• Supporting evidence-based decision making:Particularly in medical and educational fields.
• Identifying research gaps:To guide researchers toward areas needing further study.
• Improving the quality of scientific research:By providing a critical evaluation of available studies.

Types of Systematic Reviews

There are various types of systematic reviews based on the objective and methodology used, with the most prominent being:

• Quantitative Systematic Review:Focuses on collecting and analyzing numerical data from studies.
• Qualitative Systematic Review:Focuses on analyzing qualitative data such as interviews and observations.
• Mixed Methods Systematic Review:Combines quantitative and qualitative approaches to gain a deeper understanding of the topic.

Steps for Conducting a Systematic Review

To conduct a successful systematic review, the following steps must be followed:

1. Clearly Define the Research Question:

   • Formulating a specific and direct question that guides the research process.
   • Using the PICO model (Participants, Intervention, Comparison, Outcomes) to identify components of the question.

2. Setting Appropriate Study Selection Criteria:

   • Inclusion criteria:Defining the characteristics that studies must have to be included.
   • Exclusion criteria:Identifying reasons for excluding certain studies.

3. Designing a Comprehensive and Integrated Research Strategy:

   • Identifying databases and sources to be searched.
   • Developing a list of keywords and synonyms related to the topic.

4. Collecting Data from Reliable Sources:

   • Implementing the search in specified databases.
   • Recording and documenting search results accurately.

5. Analyzing and Evaluating the Quality of Selected Studies:

   • Using quality assessment tools like the ‘Cochrane’ scale to assess bias risk.
   • Evaluating the methodology of each study and the reliability of its results.

6. Extracting Results and Formulating Recommendations:

   • Summarizing key findings from the included studies.
   • Providing recommendations based on available evidence.

Study Selection Criteria in Systematic Reviews

The process of selecting studies for systematic reviews involves clear inclusion and exclusion criteria, such as:

• Study type:Determining whether studies are experimental, descriptive, or another type.
• Study quality:Using quality assessment tools to identify high-reliability studies.
• Topic relevance:Ensuring the study addresses the specific research question.

Research Tools and Methods in Systematic Reviews

To ensure comprehensive and accurate evidence collection, the following tools and methods can be used:

• Searching scientific databases:
  • Such as PubMed, Scopus, and Web of Science.
• Using keywords effectively:
  • Identifying keywords and synonyms related to the topic.
  • Using advanced search techniques to improve result accuracy.
• Critical analysis of included studies:
  • Evaluating the methodology of studies and the reliability of their results.

Challenges Facing Systematic Reviews

Despite the importance of systematic reviews in scientific research, they face many challenges that may affect the accuracy and reliability of results, with the most prominent being:

• Difficulty in finding relevant studies:
  Some studies may be published in sources that are not easily accessible or in different languages, making the search process difficult.
• Potential biases in study selection:
  Bias in selection may occur if strict criteria for including or excluding studies are not defined, which may lead to distorted results.
• Managing and analyzing data accurately and objectively:
  Dealing with large amounts of data requires advanced analysis tools, and poor analysis may lead to incorrect conclusions.
• Time and cost:
  Conducting a systematic review requires a long time and financial resources to cover database access costs and expert consultation.

The Importance of Systematic Reviews in Improving Scientific Research

Systematic reviews play a vital role in advancing the quality of scientific research by:

• Contributing to the formulation of reliable scientific policies:
  By helping make decisions based on strong evidence, which supports decision-makers in various fields.
• Enhancing future research strategies:
  By identifying research gaps and guiding future studies toward topics that need more research.
• Achieving Transparency in Scientific Research:
  As systematic review reports provide an accurate description of the methodology used, they facilitate re-evaluation and verification.

The Difference Between Systematic Review and Meta-analysis

Although both methods are used in scientific research, there are essential differences between them:

• Systematic Review:
  Focuses on comprehensively collecting and analyzing evidence without conducting in-depth statistical analysis of the results.
• Meta-Analysis:
  Involves aggregating quantitative data from different studies and conducting statistical analyses on them to reach precise quantitative conclusions.
• Integration Between Systematic Review and Meta-Analysis:
  Often, meta-analysis is used as part of a systematic review to provide a more accurate view of the studied effects.

Analysis Tools Used in Systematic Review

To ensure result accuracy, researchers use several specialized tools and software, including:

• Quantitative Data Analysis Software:
  • SPSS
  • RevMan (used in Cochrane reviews)
  • Stata
• Data Extraction and Classification Mechanisms:
  • Using standardized templates to evaluate studies.
  • Classifying studies based on quality and methodology used.

Most Databases Used in Systematic Review

Systematic review relies on reliable sources for data collection, with the most commonly used databases including:

• PubMed:
  Contains a large collection of medical and biological studies.
• Scopus:
  A multidisciplinary database including scientific articles in various fields.
• Cochrane Library:
  Specializes in medical evidence reviews and is considered one of the most reliable sources.

Evaluating Study Quality in Systematic Review

To ensure the credibility of systematic review results, study quality is evaluated using specialized measurement tools such as:

• PRISMA Standards (Preferred Reporting Items for Systematic Reviews and Meta-Analyses):
  Provide detailed guidelines to ensure accuracy and transparency in report preparation.
• Risk of Bias Assessment Standards:
  Include evaluating data collection methods, analysis methods, and the generalizability of results.

Ethics of Systematic Review in Scientific Research

Systematic review adheres to several ethical values to ensure transparency and credibility, with the most prominent being:

• Transparency in Data and Results Presentation:
  Providing all details related to the methodology used and any potential biases.
• Independence and Lack of Bias in Analysis and Interpretation:
  Avoiding conflicts of interest and ensuring objectivity during data collection and analysis.
• Credibility in Reporting:
  Documenting every step of the review to ensure it can be verified later.

Tips for Conducting a Successful Systematic Review

To ensure the success of a systematic review, the following tips can be followed:

• Select a specialized and multidisciplinary research team:
  Helps provide a comprehensive view and avoid individual biases.
• Commitment to a clear and systematic work plan:
  Setting a specific timeline to facilitate tracking progress.
• Verify the accuracy of results before publication:
  Comprehensive review to ensure result accuracy and absence of analytical errors.

Conclusion

Systematic review in scientific research is considered a powerful tool for analyzing scientific evidence accurately and comprehensively, which helps improve the quality of scientific research and support evidence-based decision-making. By following a systematic methodology based on scientific foundations, researchers can provide reviews of high scientific value that contribute to the development of various academic and professional fields.