How to Write a Systematic Review: PRISMA Guidelines
Your guide to mastering the PRISMA process for systematic reviews. Ensure your medical journal submission meets the highest standards for data extraction, risk of bias assessment, and meta-analysis reporting.
Defining the Systematic Review (SR)
A Systematic Review (SR) is a comprehensive, reproducible summary of all relevant research that addresses a clearly formulated question. It follows strict methodological criteria to minimize bias and provide reliable conclusions. The PRISMA Guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) provide the mandatory checklist for reporting these findings, ensuring transparency needed for publication in a medical journal.
The focus of this guide is the structural implementation of the PRISMA process, detailing the rigorous steps from protocol registration to meta-analysis reporting. We emphasize the necessity of transparent search strategy development and critical risk of bias assessment to establish methodological rigor.
Key Distinction:
Unlike a narrative literature review, a **Systematic Review** uses a protocol (e.g., PICO or PICOS) and documented methodology to ensure all included studies are found and appraised systematically.
Key Requirements of PRISMA Compliance
Search Strategy & Protocol
Mandatory **protocol registration** (e.g., PROSPERO) and transparent reporting of the reproducible **search strategy** used across all databases.
Risk of Bias Assessment
Critical appraisal of included studies using standardized tools (e.g., RoB 2.0) to assess methodological quality and internal validity.
PRISMA Flow Diagram
Visual mapping of the study selection process (identification, screening, eligibility, inclusion) to ensure transparency and compliance.
Phase 1 & 2: Protocol Registration and Search Strategy
Step 1: Protocol Registration (PICO Formulation)
The PRISMA process begins with **protocol registration** (e.g., PROSPERO) to prevent duplication and post-hoc changes. The protocol must clearly define the research question using the PICO framework (Population, Intervention, Comparison, Outcome) or variations like PICOS (Study Design). This initial **research question formulation** sets the boundary for the entire systematic review.
Step 2: Comprehensive Search Strategy Development
A comprehensive **search strategy** is the foundation of methodological rigor. It must be explicitly reproducible and include all relevant databases (e.g., PubMed, Embase, Cochrane Library). The search strings must use standardized vocabulary (e.g., MeSH terms) combined with free-text words. This systematic approach ensures all potential evidence is captured, minimizing **publication bias**. The full search strategy must be included in the appendix of the final review.
Struggling to develop reproducible search terms or format your PICO question? Expert help can ensure your **research question formulation** and **search strategy** are robust and compliant.
Phase 3 & 4: Screening and Risk of Bias Assessment
PRISMA Flow Diagram (Screening Process)
The **PRISMA Flow Diagram** is a mandatory visual component documenting the fate of every study identified. It clearly maps the four stages: Identification (initial search results), Screening (title/abstract review), Eligibility (full-text review), and Inclusion (final studies for synthesis). This transparency allows readers to trace the selection process, which is central to PRISMA Guidelines.
[Image of PRISMA Flow Diagram]The screening process must be conducted by at least two independent reviewers to reduce **selection bias** and ensure **methodological rigor**.
Risk of Bias Assessment (Internal Validity)
**Risk of Bias Assessment** is the critical appraisal phase. It uses domain-based tools (like Cochrane RoB 2.0 for RCTs) to judge the internal validity of included studies. You must rate each study on various bias domains (e.g., randomization, blinding, selective reporting) as high, low, or some concerns. The results of the **risk of bias assessment** directly determine the strength of the evidence synthesized. This rigorous appraisal is essential for **systematic review methodology**.
Properly executing a **risk of bias assessment** is the most complex part of the review, often requiring dedicated software and training Cochrane RoB 2.0 Handbook.
Data Extraction and Synthesis (Phase 5)
**Data extraction** involves systematically pulling key information from the included studies into a standardized **data extraction template**. This information includes study characteristics (authors, year, design), participant data, interventions, and, most importantly, the **outcome data** (means, standard deviations, confidence intervals). Just like screening, **data extraction** must be performed by two independent reviewers to ensure reliability.
Meta-Analysis Reporting (Statistical Synthesis)
A **meta-analysis** is the quantitative step where outcomes from multiple studies are statistically combined to produce a single pooled effect size. If performed, the **meta-analysis reporting** must be transparent, detailing the heterogeneity test results ($I^2$) and the specific models used (e.g., fixed-effect vs. random-effects). The results are visualized using a **Forest Plot**, which presents the pooled estimate alongside the individual study data and confidence intervals.
Reporting Bias and Publication Bias
**Publication bias** occurs when studies with positive results are more likely to be published than those with negative or null results. **Reporting bias** is similar but occurs *within* a study (e.g., selectively reporting only significant outcomes). The **Systematic Review** must address these biases, often visually through a **Funnel Plot** (for **meta-analysis**) and analytically via the **risk of bias assessment** to maintain methodological rigor.
Grading the Evidence (GRADE)
After completing the **meta-analysis** (or narrative synthesis), the overall certainty of the evidence must be graded using tools like **GRADE** (Grading of Recommendations Assessment, Development and Evaluation). **GRADE** assigns a quality rating (High, Moderate, Low, Very Low) based on study limitations (derived from **risk of bias assessment**), inconsistency, indirectness, imprecision, and publication bias. This final step is crucial for informing clinical practice guidelines BMJ, 2015 (GRADE).
Manuscript Formatting for Medical Journal Submission
The final **Systematic Review** manuscript must adhere to both the PRISMA Guidelines and the target **medical journal**’s specific formatting requirements (e.g., IMRAD structure, word limits, citation style). Pay close attention to the presentation of the **PRISMA Flow Diagram**, the **risk of bias assessment** tables, and the **meta-analysis reporting** to ensure smooth **journal submission**.
Meet the Academic Experts in Systematic Review Writing
When you hire a research paper writer for your **Systematic Review**, you are matched with a PhD expert in the **PRISMA process** and **meta-analysis** reporting.
Success in Journal Submission: Client Testimonials
Hear from students who achieved rigor in their Systematic Review methodology.
SiteJabber: 4.9/5
Trustpilot: 3.8/5
“The risk of bias assessment was flawless. The tool selection and reporting fully satisfied the medical journal submission requirements.”
– Dr. A. Patel, Research Fellow
“The meta-analysis reporting was clean, with perfect Forest Plot interpretation. The statistical synthesis elevated my Systematic Review.”
– E. Chen, Biostatistics PhD
“They ensured my PRISMA Flow Diagram and search strategy were reproducible and compliant. This level of rigor is hard to find.”
– L. Rodriguez, Nursing Research
FAQs: Systematic Review Methodology
Q: What is the PRISMA Guideline and why is it mandatory for systematic reviews?
A: PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) is an evidence-based minimum set of reporting items used to improve the transparency and reproducibility of systematic reviews. It is mandatory for most high-impact medical journals.
Q: What is Risk of Bias Assessment in a systematic review?
A: Risk of Bias Assessment is the critical evaluation of the internal validity of included studies to determine how likely their results are to be flawed due to design or execution issues (e.g., selection bias, reporting bias). Tools like Cochrane RoB 2.0 are used for this step, informing the overall rigor of the Systematic Review.
Q: What is the difference between a Systematic Review and a Meta-Analysis?
A: A Systematic Review is a comprehensive survey of existing research on a focused question. A Meta-Analysis is the optional statistical procedure often performed within a systematic review to combine the results of multiple studies quantitatively. Meta-analysis reporting uses visualization tools like the Forest Plot.
Q: What is the purpose of Protocol Registration (e.g., PROSPERO)?
A: Protocol registration ensures transparency and prevents bias (specifically publication bias). By registering the Systematic Review plan (including search strategy and risk of bias assessment plan) before searching, researchers commit to their original methodology, increasing the rigor of the eventual medical journal submission.
Achieve Journal Submission Success Today
The PRISMA process is non-negotiable for medical journal acceptance. Ensure your Systematic Review methodology, data extraction, and meta-analysis reporting meet institutional and editorial rigor.
