topic Sample size calculation crossover design in Statistical Procedures

Sample size calculation crossover design

ANKH1 — Fri, 05 Apr 2019 19:39:55 GMT

Hello,

We are designing a cross-over repeated measures design. Participants will have all 4 treatments at four different sessions. During each session, samples will be collected over several time points for 2 hrs.

Is there a SAS procedure for such calculation?

Thank you!

Re: Sample size calculation crossover design

Patrick — Sat, 06 Apr 2019 02:48:09 GMT

Are you asking for a SAS procedure creating your design or how to analyse the data you gather.

For creating the design: If you've got SAS/Stat then Proc Plan could eventually be useful for you.

https://go.documentation.sas.com/?docsetId=statug&docsetVersion=14.3&docsetTarget=statug_plan_examples07.htm&locale=en

Re: Sample size calculation crossover design

ANKH1 — Mon, 08 Apr 2019 15:01:14 GMT

Hello,

Thank you for your response. This is helpful. But I have two questions:

1) Is this proc necessary when there is a washout period? Meaning that a carry-over effect is null or minimized?

2) Is there a proc to calculate sample size?

Thanks,

Re: Sample size calculation crossover design

Patrick — Mon, 08 Apr 2019 22:43:56 GMT

@ANKH1

I'm a bit out of my depth here. May be someone else can answer your question.

@Reeza ?

Re: Sample size calculation crossover design

Reeza — Tue, 09 Apr 2019 14:59:48 GMT

PROC POWER will calculate sample sizes, not sure if your crossover design can be accommodated, but there's an example here:

https://documentation.sas.com/?docsetId=statug&docsetTarget=statug_power_examples03.htm&docsetVersion=15.1&locale=en

I'll also move this to the statistical forum.

IME, whenever you start getting into customized trial designs, simulations are the best method to determine your sample size using a bootstrap approach.

@ANKH1 wrote:

Hello,

We are designing a cross-over repeated measures design. Participants will have all 4 treatments at four different sessions. During each session, samples will be collected over several time points for 2 hrs.

Is there a SAS procedure for such calculation?

Thank you!

Re: Sample size calculation crossover design

ANKH1 — Tue, 09 Apr 2019 21:09:00 GMT

Thank you! The example is helpful.