How to Conduct a Systematic Review for a Specific Healthcare Intervention or Disease

Introduction

Systematic reviews are powerful tools for understanding the effectiveness and safety of medical interventions. But conducting one for a specific healthcare intervention or disease—such as a new cancer therapy or a diabetes management program—requires precision, structure, and attention to detail.

This article walks through the step-by-step process researchers use to produce a high-quality, targeted systematic review.

Step 1: Define a Clear Research Question

The most successful reviews start with a focused question, often using the PICO framework:

Population: Who is the patient group? (e.g., adults with type 2 diabetes)
Intervention: What treatment or approach is being studied? (e.g., continuous glucose monitoring)
Comparator: What is it compared to? (e.g., standard blood glucose monitoring)
Outcome: What is being measured? (e.g., HbA1c reduction, hospital admissions)

Step 2: Develop a Protocol

Before beginning, create a protocol—a detailed plan that outlines:

The databases to be searched
Inclusion and exclusion criteria
Data extraction methods
Risk-of-bias assessment tools

Step 3: Conduct a Comprehensive Literature Search

Search multiple databases (e.g., PubMed, Cochrane Library, Embase) and include:

Peer-reviewed journals
Grey literature (e.g., conference abstracts, theses)
Trial registries

Use a Boolean search strategy with keywords and medical subject headings (MeSH).

Step 4: Screen and Select Studies

Title and abstract screening removes clearly irrelevant studies.
Full-text screening applies inclusion criteria rigorously.
Use tools like Rayyan for blinded, independent screening by multiple reviewers.

Step 5: Extract Relevant Data

Create a standardized data extraction form to capture:

Study characteristics (year, country, design)
Population details
Intervention and comparator
Outcomes measured
Key results

Step 6: Assess Study Quality and Risk of Bias

Apply tools such as:

Cochrane Risk of Bias 2.0 (for RCTs)
ROBINS-I (for non-randomized studies)

This ensures that conclusions are based on trustworthy evidence.

Step 7: Synthesize the Evidence

Two main approaches:

Narrative synthesis — describing findings without statistical pooling.
Meta-analysis — statistically combining results for a pooled effect size.

For interventions, meta-analysis is often preferred to provide quantitative clarity.

Step 8: Interpret and Report Findings

Discuss:

The magnitude and certainty of the effect
Variations between studies
Limitations of the evidence
Clinical implications

Follow PRISMA 2020 guidelines for transparent reporting.

Example: Applied to Hypertension Treatment

Imagine conducting a review on angiotensin receptor blockers (ARBs) vs. beta-blockers for hypertension. The review might reveal that ARBs have a slightly better side-effect profile, influencing prescribing guidelines.

Conclusion

A systematic review for a specific intervention or disease is not just a literature summary—it’s a rigorous, evidence-driven process that can directly influence patient care and healthcare policy. By following a structured methodology, researchers ensure their findings are reliable, reproducible, and clinically meaningful.