We are looking at the "Sabadell score" as a predictor of long term outcome at the point of discharge from critical care in hospital.

This is an ordinal score of 0,1,2 or 3.

Most patients fall in categories 0 and 1, fewer in 2 and 3 as the "sickest" groups of patients.

I have constructed a Cox-Regression model and found that this variable violates PH assumptions (this makes sense as the effect of this variable is likely to diminish with time)

I've read with interest the following conversation on: https://protect-eu.mimecast.com/s/fB...=statalist.org

Based on this I've drafted the following code to explore the effect at 90 days (we have five year survival data):

stcox i.Sabadell, tvc(i.Sabadell) texp(exp(_t>90))

I wanted to check that my interpretation is correct:

So at 90 days the hazard ratio observed in Sabadell score 3 is reduced by a factor of 0.363 - this would mean 120.32*0.363 = 43.68 - is this right???

Would it be reasonable to re-run the analysis at one, two and three years to examine how the effect changes over time?

If so what would be the optimal way to describe/present this data?

Advice gratefully received

Ben


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