From: wangx826

Date: 08 Oct 2009 12:04:28 -0500

Thanks, Dr. Holford. But if I set a MDV column to state the missing time

points for each subject, would my logistic model still work? --I mean,

without considering censoring. I want to know if this problem leads to a

big structural error in my model. This will help me see the hidden problem

in my previous model.

Thanks,

Tianli

On Oct 8 2009, Nick Holford wrote:

*>Tianli,
*

*>
*

*>Your data sounds like it could be described by a survival analysis. A
*

*>time to event model will give you the survivor function i.e. the prob of
*

*>not having had the event as a function of time. The event in your case
*

*>is defined by the 'certain PD score'. The censoring will of course be
*

*>taken care of by a typical survival analysis.
*

*>
*

*>Nick
*

*>
*

*>wangx826 *

*>> Dear NMUsers,
*

*>>
*

*>> I am modeling ordered-categorical PD data versus time, but since the
*

*>> clinical trial is ongoing, I don't currently have complete data set
*

*>> for each subject. In other words, for some subjects, I have 1 year's
*

*>> PD data, but for some others, I can only collect PD data for 1 month.
*

*>> For the 1 month's case, it is like missing data for the rest of time.
*

*>> But I need to consider time course of the proportion of subjects who
*

*>> got a certain PD score. In my case, if I use the general logistic
*

*>> regression model to fit the relationship between time and proportions
*

*>> of event, would there be any problem? If so, how can I avoid it? Or
*

*>> need I consider censoring like survival analysis?
*

*>>
*

*>> Any suggestion would be appreciated very much.
*

*>>
*

*>> Thanks in advance,
*

*>> Tianli
*

*>> *****************************************************************
*

*>> Tianli Wang
*

*>> University of Minnesota
*

*>
*

*>*

Received on Thu Oct 08 2009 - 13:04:28 EDT

Date: 08 Oct 2009 12:04:28 -0500

Thanks, Dr. Holford. But if I set a MDV column to state the missing time

points for each subject, would my logistic model still work? --I mean,

without considering censoring. I want to know if this problem leads to a

big structural error in my model. This will help me see the hidden problem

in my previous model.

Thanks,

Tianli

On Oct 8 2009, Nick Holford wrote:

Received on Thu Oct 08 2009 - 13:04:28 EDT