[EpiData-list] Re: EpiData-list Digest, Vol 57, Issue 14

epidata-list at lists.umanitoba.ca epidata-list at lists.umanitoba.ca
Fri Jul 18 15:47:08 CDT 2008

Dear Pedro,
Thank you for your kind and the great insights!
I guess I am thinking of visit number as control variable to know
number of visits per patient which of course I could do it later on.
So I guess it was just matter of "can't wait until time of analysis to
know the answer per patient". I better hold down my horses until
analysis time then!  :-)

Best regards

On Fri, Jul 18, 2008 at 10:04 AM,
<epidata-list-request at lists.umanitoba.ca> wrote:
> Send EpiData-list mailing list submissions to
>        epidata-list at lists.umanitoba.ca
> To subscribe or unsubscribe via the World Wide Web, visit
>        http://lists.umanitoba.ca/mailman/listinfo/epidata-list
> or, via email, send a message with subject or body 'help' to
>        epidata-list-request at lists.umanitoba.ca
> You can reach the person managing the list at
>        epidata-list-owner at lists.umanitoba.ca
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of EpiData-list digest..."
> EpiData-list mailing list
> ___________________________________
> Today's Topics:
>   1. Visit number (epidata-list at lists.umanitoba.ca)
> ---------- Forwarded message ----------
> From: epidata-list at lists.umanitoba.ca
> To: epidata-list at lists.umanitoba.ca
> Date: Fri, 18 Jul 2008 09:47:07 -0300
> Subject: [EpiData-list] Visit number
> Dear Ziad,
> Of course a visit number is interresting... if you want visualize your data
> and order it by visit number. Having a visit number at your paper forms is
> also interresting for the very same reason.
> However, most analysis softwares such as R and Stata do not bother with the
> visit number while running survival analysis - which I guess you will do
> later. :)  For survival analysis the most important data is the date of the
> evaluation, somehting indicatig what happened at the period, and a date
> indicating the beggining of the period. Most softwares have available
> analysis whith time dpending variables - which has a dataset wiht a
> structure containing the same patient at several lines - each line a
> different period. Of course to do that, there must a unique idenfier for
> each patient which will be repeated all the lines where the same patient
> appear.
> Again, visit number is important but not that importatn. As a previous
> answered, if you already started your job and you have a lot of data in your
> dataset it will be easier to insert a variable indicating visit number.
> Otherwise, you could update you qes file with a nwe variable indicating
> visit number.
> Best regards,
> Pedro Emmanuel
> ________________________________________
> EpiData-list at lists.umanitoba.ca
> http://lists.umanitoba.ca/mailman/listinfo/epidata-list

Ziad El-Khatib
National Institute for Communicable Diseases (NICD)
1 Modderfontein Road
Private Bag X4, Sandringham, 2131
Johannesburg, South Africa
Mobile: +27 (0) 72-52 39 716
Phone: +27 (0) 11-386 6433
Fax (NICD): +27 (0) 11 386 6453
Fax (connected to my email): +27 (0) 86 18 2871

Division of International Health (IHCAR)
Department of Public Health Sciences
Karolinska Institute
Nobels väg 9
SE-171 77
Stockholm, Sweden
Landline (connected to Skype):+46 (0) 8-559 21 659
Fax: +46 (0) 8-311590

More information about the EpiData-list mailing list