Jason Leung

5 Questions 34 Answers 0 Followers

Questions related from Jason Leung

Why is there a discrepancy in p-values for different output tables in a mixed model when an interaction term is included (SAS)?

I found that by using Proc Mixed in SAS to run a repeated measure ANOVA, the p-values from the table "Solution for Fixed Effects" are different from the table "Type 3 Tests of Fixed Effects" when...

06 June 2014 1,782 6 View

Is it good to use IPW (Inverse Probability Weighting) to adjust for selection bias due to loss to follow up in cohort study?

In a cohort study, risk factor of frailty is analyzed. However, the subjects lost to follow up were more frail at baseline. So there is selection bias. Is it good to use IPW (Inverse Probability...

03 March 2013 9,836 31 View

Can a larger sample size reduces type I error? and how to deal with the type I error when many outcomes and independent variables needed to be tested?

I am working on the sample size calculation. There are many outcomes and many independent variables needed to be tested. The type I error rate will be increased due to many hypothesis testings....

07 July 2012 9,045 8 View

Would I use independent 2 samples or paired samples T test to test for mean difference between age-sex-matched samples with ratio 1:2?

I have a case group and a control group, which is age-sex-matched with ratio 1 case: 2 control. I'm wondering what test is suitable to test their mean difference. To test matched groups, some...

05 May 2012 2,249 39 View

Difference between ordinal and scale in SPSS

Is there any difference in SPSS to specify a variable as ordinal or scale? I know they are different in meaning, but it seems SPSS treat them the same in calculation.

02 February 2012 7,629 23 View