xtset panelvar timevar, daily

[Talar Markossian]

Hi - would xtset the dataset with panelvar and timevar, daily account for the length of time interval between the panel observations. The timevar is the date of visit when the outcome variable was observed and the dataset is not balanced. I am aware that the order of visits is already specified by xtset with timevar, how about the interval of time between the panel visits (which is relevant for our analysis)? Do I additionally need to control for the time interval between visits in my models or is it already specified within xtset with timevar? Thank you.

[Nick Cox]

If you have irregular dates, there is so far as I know no gain and some loss in declaring a time variable as well as a panel variable. In any case, what analyses do you plan that depend on your dataset being xtset?

[Talar Markossian]

The outcome variable is categorical (0/non-present; 1/mild; and 2/severe). These are patients visiting their provider over three years period, no set intervals between visit, on average 2-5 visits. We want to examine if their outcome got better or worse over time. I was thinking of xtoprobit?

[Nick Cox]

I have never used xtoprobit but a glance at the help suggests that you don't need to declare a time variable.

[Talar Markossian]

Ok, thank you for the input. Talar