Unequal time intervals in multi-state models

questions concerning analysis/theory using program MARK

Unequal time intervals in multi-state models

Postby Jen » Wed May 09, 2012 1:37 am

I have 2 populations (1 with equal capture occasions and 1 with unequal capture occasions) and I want to be able to obtain comparable survival and transition rates using multi-state models. I already have my estimates for the population with consistent capture occasions but am unsure whether my estimates for the population with unequal time intervals are robust.

The model I want to re-create is state dependent survival and transition (i.e. not time varying) I am happy working in Mark and RMark so any options in either would be great.

Currently I have just included the time intervals when processing the data initially as although I have read about the issues with this method I am not sure what my other options are. It does produce comparable estimates but I am obviously worried about the validity of this method. I have read that dots can be included however unfortunately it’s not possible with this data as there is no common denominator with intervals of: 0.923077, 0.153846, 2.923077, 4, 1, 3, 1.

Any suggestions on how I can obtain comparable estimates would be much appreciated.

Thank you for your help.
Jen
 
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Joined: Thu May 12, 2011 7:42 am

Re: Unequal time intervals in multi-state models

Postby cooch » Wed Jun 20, 2012 5:16 pm

Jen wrote:I have 2 populations (1 with equal capture occasions and 1 with unequal capture occasions) and I want to be able to obtain comparable survival and transition rates using multi-state models. I already have my estimates for the population with consistent capture occasions but am unsure whether my estimates for the population with unequal time intervals are robust.

The model I want to re-create is state dependent survival and transition (i.e. not time varying) I am happy working in Mark and RMark so any options in either would be great.

Currently I have just included the time intervals when processing the data initially as although I have read about the issues with this method I am not sure what my other options are. It does produce comparable estimates but I am obviously worried about the validity of this method. I have read that dots can be included however unfortunately it’s not possible with this data as there is no common denominator with intervals of: 0.923077, 0.153846, 2.923077, 4, 1, 3, 1.

Any suggestions on how I can obtain comparable estimates would be much appreciated.

Thank you for your help.


See viewtopic.php?f=1&t=2171
cooch
 
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Joined: Thu May 15, 2003 4:11 pm
Location: Cornell University


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