BookmarkSubscribeRSS Feed
PharmlyDoc
Quartz | Level 8

This is a retrospective observational study looking at a binary outcome (1=yes, 2=no). 

Overall sample of 100,000 patients.

70% of patients are in the no group and 30% in the yes group. Am I still okay to use chi square tests to compare categorical variables as long as table cells contain more than 5 observations?

For univariable statistics comparing continuous variables between the two groups - for example, age in years - am I okay to use a two-sample T-test?

Also, my distribution for age is somewhat bimodal  

 

Screen Shot 2021-06-23 at 8.21.38 PM.png

 

 

 

5 REPLIES 5
Reeza
Super User

Since it's almost 2:1 why not do a case control matching instead?

Ksharp
Super User
If it was following NORMAL distribution ,then try ttest ,otherwise wilcoxon
SteveDenham
Jade | Level 19

Or PROC FMM.  That plot looks like a classic mixture of a normal and a gamma distribution.

 

SteveDenham

Ksharp
Super User
It can compare the difference of mean between two groups , like proc ttest ?
SteveDenham
Jade | Level 19

No, but what it can do is a Bayesian analysis, where the mean, standard deviation and credible interval bounds of the posterior distributions are reported.

 

Granted that this approach may be using a bazooka to swat a fly...

 

SteveDenham

sas-innovate-2024.png

Available on demand!

Missed SAS Innovate Las Vegas? Watch all the action for free! View the keynotes, general sessions and 22 breakouts on demand.

 

Register now!

What is ANOVA?

ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.

Find more tutorials on the SAS Users YouTube channel.

Discussion stats
  • 5 replies
  • 440 views
  • 4 likes
  • 4 in conversation