Lesson 5 – Systematic Literature Review Course: Screening Literature

Missed last week? Read our Past Lesson: Systematic Literature Review Course: Understanding the State of the Art (SoTA) for Medical Devices. Be sure to check it out if you haven’t already!”

Screening Literature: A Comprehensive Guide for Effective Review

Screening literature is a pivotal step in the systematic review process. It ensures that only the most relevant and credible studies are included, helping to build a solid foundation for your research. This post will guide you through the best practices for screening literature, focusing on inclusion/exclusion criteria, abstract review strategies, and handling scarce data scenarios.

Setting Inclusion and Exclusion Criteria

Before diving into abstract reviews, it’s critical to establish clear inclusion and exclusion criteria. These criteria act as a roadmap, guiding you in determining which studies align with your research objectives. For instance:

• Inclusion Criteria:
  • Clinical studies on the specific medical device or comparable devices.
  • Studies involving relevant patient populations.
  • Outcomes related to safety and performance.
• Exclusion Criteria:
  • Animal studies.
  • Editorials or expert opinions without empirical evidence.
  • Articles lacking data on safety or performance metrics.

Tools like keyword highlighting can streamline this process. By marking exclusionary keywords (e.g., “animal studies”) in bright red, you can visually scan abstracts and quickly exclude irrelevant material. As you refine your criteria, update the keywords to enhance efficiency.

Abstract Screening: A Step-by-Step Framework

Abstract screening is one of the most time-consuming tasks in the review process. However, adopting a structured approach can make it more efficient. Here’s how:

1. Initial Exclusion Pass

Focus on excluding irrelevant articles during the first pass. Quickly scan the title and abstract for disqualifiers such as non-human studies or lack of device relevance. This “lightning round” aims to eliminate noise and retain only potentially relevant studies.

2. Key Elements to Identify

When reviewing abstracts, prioritize the following:

• Relevance: Does the abstract mention the medical device or a comparable one?
• Population: Is the study’s patient population aligned with the device’s intended use?
• Outcomes: Are the reported outcomes relevant to safety, performance, or other key metrics?

3. Categorize Studies

Assign studies to one of three categories:

• Included: Clearly relevant articles.
• Maybe: Ambiguous articles requiring a full-text review.
• Excluded: Studies that fail to meet criteria.

4. Dive Deeper When Needed

If an abstract lacks detail, place it in the “maybe” category for further evaluation. Full-text reviews will allow for a more comprehensive assessment of its relevance.

Understanding Evidence Types

The type of evidence presented in a study can significantly impact its value in your review. Below is a hierarchy of evidence types to help prioritize your selections:

1. Systematic Reviews and Meta-Analyses: Provide high-level evidence by synthesizing data from multiple studies.
2. Randomized Controlled Trials (RCTs): Offer robust evidence through random assignment and control groups.
3. Non-Randomized Controlled Trials: Useful but more prone to biases.
4. Cohort Studies (Prospective): Follow groups over time to assess outcomes.
5. Case-Control and Cross-Sectional Studies: Offer valuable insights but have limitations in causality.
6. Case Series and Reports: Descriptive but lack generalizability.
7. Animal and Laboratory Studies: Foundational but excluded from clinical reviews.

When Data is Scarce

Sometimes, searches yield limited or no relevant studies for your specific device. Here’s how to handle such situations:

1. Broaden Search Terms

Adjust your search to include related devices, broader categories, or wildcard terms (e.g., “device*” to capture variations).

2. Leverage Indirect Evidence

Look for studies on similar devices or broader categories to draw indirect comparisons.

3. Consult Experts

Gather insights from field experts to supplement gaps in published data.

4. Plan Post-Market Surveillance

If pre-market data is lacking, focus on gathering robust post-market data to support future claims.

Best Practices for Documenting Exclusions

It’s crucial to document the reason for each exclusion, whether you’re using tools like CiteMed or Excel. This ensures transparency and prepares you for potential audits.

Conclusion

Screening literature effectively is both an art and a science. By setting clear criteria, adopting a structured review framework, and understanding evidence hierarchies, you can streamline the process and focus on the most impactful studies. Whether you’re working with abundant data or navigating scarcity, these strategies will help you build a robust evidence base for your research.

Have questions or need further guidance? Drop a comment below or reach out for personalized advice!