Critical Appraisal Skills Programme (CASP) -12 Questions To Help You Make Sense Of A Diagnostic Test Study Checklist

(A) Are The Results Of The Study Valid?

Screening Questions

1. Was there a clear question for the study to address?

HINT: A question should include information about

• The population
• The test
• The setting
• The outcomes

Yes Can’t tell No

2. Was there a comparison with an appropriate reference standard?

HINT: Is this reference test(s) the best available indicator in the circumstances?

Yes Can’t tell No

Is it worth continuing?

Detailed Questions

3. Did all patients get the diagnostic test and reference standard?

HINT: Consider

Were both received regardless of the results of the test of interest Check the 2X2 table (verification bias)

Yes Can’t tell  No

4. Could the results of the test have been influenced by the results of the reference standard?

HINT: Consider

• Was there blinding?
• Were the tests performed independently
  (Review bias)

Yes Can’t tell  No

5. Is the disease status of the tested population clearly described?

HINT: Consider

• Presenting symptoms
• Disease stage or severity
• Co-morbidity
• Differential diagnoses (Spectrum Bias)

Yes Can’t tell  No

6. Were the methods for performing the test Described in sufficient detail?

HINT: Consider

• Was a protocol followed?

Yes Can’t tell  No

(B) If So, What Are The Results?

7. What are the results?

HINT: Consider

Are the sensitivity and specificity and/or likelihood
ratios presented?
Are the results presented in such a way that
We can work them out?

Yes Can’t tell No

8. How sure are we about the results? consequences and cost of alternatives performed?

HINT: Consider

• Could they have occurred by chance?
• Are there confidence limits?
• What are they?

Yes Can’t tell No

(C) Will The Results Help Me And My Patients/Population?

(Consider whether you are primarily interested in the impact on a population or individual level)

9. Can the results be applied to your patients/the population of interest?

HINT: Do you think your patients/population are so different from those in the study that the results cannot be applied?
Such as age, sex, ethnicity and spectrum bias.

Yes Can’t tell No

10. Can the test be applied to your patient or population of interest?

HINT: Consider

• Resources and opportunity costs
• Level and availability of expertise required to Interpret the tests
• Current practice and availability of services

Yes Can’t tell No

11. Were all outcomes important to the individual or population considered?

HINT: Consider

• Will the knowledge of the test result improve patient wellbeing?
• Will the knowledge of the test result lead to a change in patient management?

Yes Can’t tell No

12. What would be the impact of using this test on your patients/population?

Yes Can’t tell No