topic Re: Test for significant difference for experiment repeated over 3 days and measurements over 6 hour in SAS Programming

Test for significant difference for experiment repeated over 3 days and measurements over 6 hours

FrancoisN — Fri, 21 Oct 2022 11:36:03 GMT

Hi SAS community,

I have a dataset where I need to test whether there are significant differences between GroupA and GroupB. GroupA and GroupB are values obtained from an experiment that was repeated over 3 days (Day = 1, 2, 3). Measurements are obtained over 6 hours for each of the 3 days starting at 0 (Hour = 0, 1, 2, 3, 4, 5, 6). Any assistance will be greatly appreciated.

The code for the data are below:

data Data1;
input Day Hour GroupA GroupB;
datalines;
1 0 240000000 190000000
1 1 1000000000 4000000000
1 2 800000000 13000000000
1 3 23000000000 15000000000
1 4 15000000000 30000000000
1 5 24000000000 30000000000
1 6 30000000000 30000000000
2 0 9000000000 8000000000
2 1 290000000 1900000000
2 2 5000000000 13000000000
2 3 5000000000 30000000000
2 4 25000000000 30000000000
2 5 18000000000 30000000000
2 6 30000000000 30000000000
3 0 2200000000 30000000000
3 1 1200000000 30000000000
3 2 9000000000 10000000000
3 3 21000000000 30000000000
3 4 30000000000 30000000000
3 5 30000000000 30000000000
3 6 30000000000 30000000000
;

Thank you so much,

Francois

Re: Test for significant difference for experiment repeated over 3 days and measurements over 6 hour

FrancoisN — Mon, 24 Oct 2022 07:45:35 GMT

Perhaps I can provide some additional information to my question above. My speciality is sampling. I know the basics of proc glm, proc mixed, proc anavo, proc ttest and so, but since the values are obtained hourly, the values per group are not independent of each other, so I don't think this proc glm or so will work. I was told that I will have to do survival analysis using proc PHReg. I don't know proc PHReg and am not sure if survival analysis is the correct method to determine if the groups differ significantly from one another. So any assistance will be appreciated.

Re: Test for significant difference for experiment repeated over 3 days and measurements over 6 hour

Ksharp — Mon, 24 Oct 2022 12:28:11 GMT

Better post it at Stat Forum:
https://communities.sas.com/t5/Statistical-Procedures/bd-p/statistical_procedures

Re: Test for significant difference for experiment repeated over 3 days and measurements over 6 hour

Ksharp — Mon, 24 Oct 2022 12:30:21 GMT

and calling @StatDave @SteveDenham

Re: Test for significant difference for experiment repeated over 3 days and measurements over 6 hour

PaigeMiller — Mon, 24 Oct 2022 12:44:35 GMT

Perhaps this example from PROC MIXED will get you started

https://documentation.sas.com/doc/en/pgmsascdc/9.4_3.4/statug/statug_mixed_examples02.htm