help forstarjas-------------------------------------------------------------------------------

Title

starjas-- Arjas plot to check proportional hazards assumption

Syntax

starjasvarname[ifexp] [inrange] [,adjust(varlist)levelplot(#[#] ..)atobs(#)rrglance(#)twoway_options]

optionsDescription ------------------------------------------------------------------------- Optionsadjustspecify the variables fitted in the Cox model before checking ifvarnameis proportionallevelplotspecify the levels ofvarnameto be displayed in the plotatobsrestrict the plot to the first#eventsrrglancedraw a line approximately corresponding in the case of binary covariate to a#relative riskY-Axis, X-Axis, Caption, Legend

twoway_optionssome of the options documented in[G]twoway_optionsAdd plotplot(plot)add other plots to generated graph -------------------------------------------------------------------------You must

stsetyour data before usingstarjas; seestset.

Description

starjasgraphs Arjas plot by one categorical variable declared invarname.Arjas plots allow to check if a covariate should be included in a proportional hazards model and if it has proportional hazards effect. If a covariate does not need to be in the model, then for each level a roughly 45° line through origin should be plotted. Otherwise Arjas plot will give curves which are approximately linear but with slope differing from 1. If a covariate has a nonproportional effect on the hazard rate, then the curves will differ nonlinearly from 45° line. Assume an indicator variable having only two values, the curve for the level 1 should be concave if the hazard ratio is increasing in

twhereas the curve for the level 0 should be convex.

Examplesuse "C:\Data\BMT", clear starjas MTX, legend(pos(5) ring(0)) lw(medthick) starjas Z7cat, adjust(MTX Z1-Z6) legend(pos(5) ring(0)) lc(green navy red brown)

Downloading ancillary files in one of your

`"`c(adopath)'"'directory you can run this example.

(click to run)

Also seeManual:

[S] st stcoxOnline: stcox postestimation, stcox diagnostics

ReferencesKlein JP, and Moeschberger ML: Survival Analysis: techniques for Censored and Truncated Data - 2nd ed. (2003), p. 369 - 374. Springer

AuthorsEnzo Coviello (enzo.coviello@alice.it)