CASP Checklist -11 questions to help you make sense of a Randomised Controlled Trials

(A) Are the results of the trial valid?

Screening Questions

1. Did the trial address a clearly focused issue?
HINT: An issue can be ‘focused’ In terms of

• The population studied
• The intervention given
• The comparator given
• The outcomes considered

Yes Can’t tell No

2. Was the assignment of patients to treatments randomised?
HINT: Consider

• How was this carried out?
• Was the allocation sequence concealed from researchers and patients?

Yes Can’t tell No

3. Were all of the patients who entered the trial properly accounted for at its conclusion?
HINT: Consider

• Was the trial stopped early?
• Were patients analysed in the groups to which they were randomised?

Yes Can’t tell No

Is it worth continuing?

Detailed questions

4. Were patients, health workers and study personnel ‘blind’ to treatment?
HINT: Think about

• Patients?
• Health workers?
• Study personnel?

Yes Can’t tell No

5. Were the groups similar at the start of the trial?
HINT: Look at

• Other factors that might affect the outcome such as age, sex, social class

Yes Can’t tell No

6. Aside from the experimental intervention, were the groups treated equally?

Yes Can’t tell No

(B) What are the results?

7. How large was the treatment effect?
HINT: Consider

• What outcomes were measured?
• Is the primary outcome clearly specified?
• What results were found for each outcome?

Yes Can’t tell No

8. How precise was the estimate of the treatment effect?
HINT: Consider

• What are the confidence limits?

Yes Can’t tell No

(C) Will the results help locally?

9. Can the results be applied in your context? (or to the local population?)
HINT: Consider whether

• Do you think that the patients covered by the trial are similar enough to the patients to whom you will apply this?, if not how to they differ?

Yes Can’t tell No

10. Were all clinically important outcomes considered?
HINT: Consider

• Is there other information you would like to have seen?
• If not, does this affect the decision?

Yes Can’t tell No

11. Are the benefits worth the harms and costs?
HINT: Consider

• Even if this is not addressed by the trial, what do you think?

Yes Can’t tell No