I hope this is the right forum to ask as cox regression is usually use by bio-statisticians.

My research is about companies which producing either product A or product B. This companies will either distress (1) or stay healthy (0). The time of production for product A/B are varies, but i set the end time of observation as the same, i.e. year 2013. The data is in annual form.

I am using SPSS and following are the variables:

Dependent variable: distress (1), healthy (0) [selected as status in SPSS]

Time to event : years of after production until distress/year 2013 [selected as time in SPSS]

Time dependent: T*_SIZE

Independent variables/covariates: 5 variables including SIZE. All are in the form of financial ratios

My question is:

1. whether the data is correct

2. can i have more than one time dependent variable? My covariates are all financial variables and it will change over time, hence time dependent?

3. since the covariates are changing over time, should I take average data for all observation period from production year until year of distress/year 2013?

Appreciate any feedback. I thank you in advance !