How to use CASP (Critical Appraisal Skills Programme) Systematic Review Checklist

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How to Use the CASP Systematic Review Checklist

The CASP (Critical Appraisal Skills Programme) Systematic Review Checklist is a user-friendly tool designed to help researchers, clinicians, and students critically appraise systematic reviews for validity, relevance, and reliability. Unlike PRISMA (which guides reporting) or AMSTAR-2/ROBIS (which assess methodological quality/bias), CASP provides a simplified, question-based approach for quick evaluation.

CASP Systematic Review Checklist: Step-by-Step Guide

1. Understand the Structure

The CASP checklist consists of 10 key questions, divided into three sections:

  1. Validity (Are the results trustworthy?)
  2. Results (What are the findings?)
  3. Applicability (Can the results be applied to your context?)

Each question is answered with:
✅ Yes (Low risk of bias)
❌ No (Potential flaw)
❓ Can’t tell (Insufficient information)

2. Detailed Breakdown of the 10 Questions

Section A: Validity (Q1-Q5)

Q1. Did the review address a clearly focused question?

  • Check if the PICO (Population, Intervention, Comparison, Outcome) is well-defined.

Q2. Did the authors look for the right type of studies?

  • Were appropriate study designs (RCTs, cohort studies) included?
  • Were key databases (PubMed, Cochrane) searched?

Q3. Do you think all relevant studies were included?

  • Was the search strategy comprehensive (no language/date restrictions)?
  • Was grey literature (unpublished studies, conference abstracts) considered?

Q4. Did the review authors assess the quality of included studies?

  • Was a risk of bias tool (e.g., Cochrane RoB, Newcastle-Ottawa) used?

Q5. If the results were combined, was it reasonable to do so?

  • Were studies homogeneous enough for meta-analysis?
  • Was heterogeneity assessed (I² statistic, subgroup analysis)?

Section B: Results (Q6-Q8)

Q6. What are the overall results?

  • Are effect sizes (RR, OR, mean difference) clearly reported?

Q7. How precise are the results?

  • Are confidence intervals (CIs) provided?

Q8. Were all important outcomes considered?

  • Did the review assess harms, costs, or patient-reported outcomes (if relevant)?

Section C: Applicability (Q9-Q10)

Q9. Can the results be applied to your population?

  • Are the included studies similar to your patients/setting?

Q10. Were all key outcomes considered?

  • Do the findings align with your clinical/research priorities?

3. How to Score & Interpret CASP

  • No formal scoring system (unlike AMSTAR-2).
  • More “Yes” answers = Higher confidence in the review.
  • “No” or “Can’t tell” answers indicate limitations.

Example Assessment

Question Response Comment
Q1 (Focused question) ✅ Yes Clear PICO framework.
Q3 (All relevant studies) ❌ No Only English studies included.
Q5 (Reasonable synthesis) ❓ Can’t tell Heterogeneity not discussed.
Overall Impression Moderate reliability Limited by language bias.

4. When to Use CASP?

✔ Quickly appraising SRs for clinical decision-making.
✔ Teaching critical appraisal (simpler than AMSTAR-2/ROBIS).
✔ Screening multiple reviews before deeper analysis.

CASP vs. Other Tools

Feature CASP AMSTAR-2 ROBIS
Focus Quick appraisal Methodological quality Bias risk
Best for Beginners, clinicians Researchers, guideline developers Bias detection
Time Required 5–10 mins 15–30 mins 20–40 mins

Strengths of CASP

✔ Simple & intuitive (ideal for non-experts).
✔ Free and widely accessible.
✔ Covers key validity, results, and applicability issues.

Limitations

✖ Less detailed than AMSTAR-2 or ROBIS.
✖ No overall score (subjective interpretation needed).

Conclusion

The CASP checklist is a practical, beginner-friendly tool to assess systematic reviews efficiently. While it doesn’t replace AMSTAR-2 or ROBIS for in-depth appraisal, it’s perfect for rapid screening or educational purposes.

Published by oriaku