3. Randomised controlled trials

Questions to ask when reading a report of an RCT.
This is module three of seven critical appraisal training videos. In this third video, we introduce the fundamentals of randomised controlled trials and the ways in which we can apply the critical appraisal concepts of validity, trustworthiness of results, and value and relevance using the CASP checklist.
Please follow this link for the CASP randomised controlled trials checklist: casp-uk.net/wp...
Please follow this link for the full text version of the study by Sugg et al (2018): bmjopen.bmj.co...
Please follow this link for the test your knowledge quiz: www.tryinterac...
The project was developed to enhance research use and development across two NHS Trusts. The project founding partners were:
- Cochrane Common Mental Disorders
- Northumberland, Tyne and Wear NHS Foundation Trust (NTW), UK
- Tees, Esk and Wear Valleys NHS Foundation Trust (TEWV), UK
Delivery of the project was supported by the Centre for Reviews and Dissemination at the University of York.
Funding Acknowledgement:
The production of the critical appraisal modules was jointly funded by:
- Economic and Social Research Council (ESRC), UK - as part of the University of York ESRC Impact Acceleration Account (ES/M500574/1)
- Northumberland, Tyne and Wear NHS Foundation Trust (NTW), UK
- Tees, Esk and Wear Valleys NHS Foundation Trust (TEWV), UK
- University of York, UK
Cochrane Review Group Funding Acknowledgement: The National Institute for Health Research (NIHR) is the largest single funder of the Cochrane Common Mental Disorders Group.
Disclaimer: the views and opinions expressed herein are those of the module authors and do not necessarily reflect those of the ESRC, NIHR, the National Health Service (NHS), the Department of Health and Social Care or the University of York.

[@Rene-uz3eb]

I think they need to standardized prerequisites for trials, stratified by nutritional status. Is this medicine useful for people who have an i sufficient diet? Is it useful for people whose blood test shows they don't have any deficiencies? EDIT: Seems obvious that the trials should be paid for by the companies that make the meds, but not conducted by them.

[@KS-vz3cy]

Does anybody know, if there is a new, working link for the quiz?

[@bbmello1]

The quizzes no longer work, it says you need to reactivate them

[@Random-xw1fg]

I was lost, now I'm found thanks to you and this series.

[@amybodden8305]

A fantastic series of videos - very helpful! Thank you.

[@CochraneMentalHealth]

Really glad you found them helpful!

[@susanlarkin3322]

Very helpful, thank you

[@aneesakhan8502]

How can I answer question 8 if the article doesn’t show confidence intervals help

[@CochraneMentalHealth]

Good question: There are a few ways of working around this: 1) If the study provides data where you could calculate the confidence interval that's a good option (only takes a minute or so to plug into RevMan, Stata etc). E.g. if they provide means, SD, sample size or for dichotomous outcomes number of events and number of participants 2) If you don't have the above data - you could also look at sample size. Either informally by making a judgement based on the sample size or more formally by calculating an optimal information size. Hope this helps.

[@bobiguzman]

Really very helpful! Informative, educational, simply presented! Thank you!

[@CochraneMentalHealth]

Glad it was helpful. Thanks for the feedback.

[@agnieszkalazell5904]

Thank you so much!very helful

[@CochraneMentalHealth]

Link for the series: kzbin.info/aero/PLKav5fAJIAOJark_WyTcOb_wKIwjNJ35s

[@iestynmalaki9712]

Thanks for this!! Just one question what if its an open labeled RCT?

[@CochraneMentalHealth]

In an open label trial, the participants and the researchers know to which study arm participants are allocated. This relates to sections of the video on detection bias and blinding, and item 4 of the CASP checklist.

[@sunikeerison7366]

Thanks for the video super it's concise!!

[@CochraneMentalHealth]

Glad it was helpful. Thanks for the feedback.

[@alexdefeatntds]

Nice video

[@BlessedLPT.]

really useful video, thanks

[@CochraneMentalHealth]

Glad it was helpful!

[@عزالدينالشيخسليمان]

This is a treasure, thanks a lot for making this highly informative video, appreciate your time and efforts

[@rachelchurchill8235]

Really glad you found it helpful. We always appreciate the feedback.

[@aneesakhan8502]

If one group is in USA and one in U.K. for question 6 could u point out that it may be not equal

[@CochraneMentalHealth]

Depends on the type of intervention and comparator. For some interventions (e.g. service level interventions like assertive outreach) the nature of the healthcare system could make an important difference to outcomes so it would be good to note. Whereas if you were to look at other interventions (e.g. pharmacological interventions) where the study was conducted often may not be as important. Hope this helps.

[@chudkrissy]

thank you for this video, really informative and logical. Questions is a randomised crossover trial a form of a RCT? really hard to find a definitive answer in literature

[@CochraneMentalHealth]

Hi Kristabel. Yes, a randomised cross-over trial is a form of RCT. The first phase of a cross-over trial is similar to a parallel RCT; participants in two (or more) groups are randomised to receive an intervention or control. After a period of time, in the second phase of the cross-over trial, groups swap interventions and receive the other intervention or control.