Appraising Randomised Controlled Trials: Using the CASP Checklist

This document presents the Critical Appraisal Skills Programme (CASP) checklist, a tool designed to help users systematically evaluate the validity, results, and applicability of randomised controlled trials (RCTs). The checklist comprises 11 questions divided into three sections. Section A focuses on the validity of the trial results, addressing issues such as the clarity of the research question, randomization of patients, and accounting for all participants. Section B assesses the results, including the size and precision of the treatment effect. Section C explores the applicability of the results to a local population, considering all clinically important outcomes, and weighing benefits against harms and costs. The document provides guidance on using the checklist, including prompts to consider for each question. The checklists were designed to be used as educational tools and are based on JAMA 'Users’ guides to the medical literature 1994. This resource is available on Desklib, a platform offering AI-based study tools, past papers, and solved assignments to students.

CASP Checklist:11 questions to help you make sense of a Randomised Controlled Trial
How to use this appraisal tool: Three broad issues need to be considered when app
trial:
Are the results of the study valid? (Section A)
What are the results? (Section B)
Will the results help locally?(Section C)
The 11 questions on the following pages are designed to help you think about these iss
systematically. The first three questions are screening questions and can be answered
quickly. If the answer to both is “yes”, it is worth proceeding with the remaining questions.
There is some degree of overlap between the questions, you are asked to record a “yes”,
“no” or “can’t tell” to most of the questions. A number of italicised prompts are given after
each question. These are designed to remind you why the question is important. Recor
reasons for your answers in the spaces provided.
About: These checklists were designed to be used as educational pedagogic t
workshop setting, therefore we do not suggest a scoring system. The core CA
(randomised controlled trial & systematic review) were based on JAMA 'Users’ guides to the
medical literature 1994 (adapted from Guyatt GH, Sackett DL, and Cook DJ), and piloted
health care practitioners.
For each new checklist, a group of experts were assembled to develop and pilot the che
and the workshop format with which it would be used. Over the years overall adjustmen
have been made to the format, but a recent survey of checklist users reiterated that th
format continues to be useful and appropriate.
Referencing: we recommend using the Harvard style citation, i.e.: Critical Appr
Programme (2018). CASP (insert name of checklist i.e. Randomised Controlled Trial) Ch
[online] Available at: URL. Accessed: Date Accessed.
©CASP this work is licensed under the Creative Commons Attribution– Non-Commercial-
Share A like. To view a copy of this license, visit http://creativecommons.org/licenses/by
sa/3.0/ www.casp-uk.net
Critical Appraisal Skills Programme (CASP) part of Oxford Centre for Triple Value Healthcare Ltd www.casp-uk.net

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Section A: Are the results of the trial valid?
1. Did the trial address a clearly
focused issue?
Yes HINT: An issue can be‘focused’ In terms of
• the population studied
• the intervention given
• the comparator given
• the outcomes considered
Can’t Tell
No
Comments:
2. Was the assignment of
patients to treatments
randomised?
Yes HINT: Consider
• how this was carried out
• was the allocation sequence concealed
from researchers and patients
Can’t Tell
No
Comments:
3. Were all of the patients
who entered the trial
properly accounted for at
its conclusion?
Yes HINT: Consider
• was the trial stopped early
• were patients analysed in the groups to
which they were randomised
Can’t Tell
No
Comments:
Is it worth continuing?
Paper for appraisal and reference:

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4. Were patients, health
workers and study personnel
‘blind’ to treatment?
Yes
Can’t Tell
No
Comments:
5. Were the groups similar at
the start of the trial
Yes HINT: Consider
• other factors that might affect the
outcome, such as; age, sex, social classCan’t Tell
No
Comments:
6. Aside from the experimental
intervention, were the groups
treated equally?
Yes
Can’t Tell
No
Comments:
Section B: What are the results?

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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
Comments:
8. How precise was the estimate of the treatment
effect?
HINT: Consider
• what are the confidence limits
Comments:
Section C: Will the results help locally?
9. Can the results be applied to
the local population, or in
your context?
Yes HINT: Consider whether
• the patients covered by the trial are
similar enough to the patients to whom
you will apply this
• how they differ
Can’t Tell
No
Comments:
10. Were all clinically important
outcomes considered?
Yes HINT: Consider whether
• there is other information you would
like to have seen
• if not, does this affect the decision
Can’t Tell
No
Comments:

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11. Are the benefits worth the
harms and costs?
Yes HINT: Consider
• even if this is not addressed by the
trial, what do you think?Can’t Tell
No
Comments: