# st: Question about graphing hazard functions

 From [email protected] To Statalist <[email protected]> Subject st: Question about graphing hazard functions Date Tue, 18 Jan 2005 21:34:34 -0500

I am using multiple-record-per-case data (stsplit at failures) to model rates of exit and of change for kids in foster care using models of the general form r(j)k(t)= exp[BX(t)] ((j) and second (t) are subscripted) where X(t) is a vector of time-varying variables and B is a vector of parameters indicating the effects of the variables on rate of exit or of change. I would like to illustrate graphically the independent effect of selected variables on the hazard rate using point estimates from my models. However, I am having a difficult time doing this as I can't figure out how to get STATA to use time on the x axis (I can only get a constant rate curve using stcurve). For example, the coefficient associated with the variable measuring time-of-duration in previous placement is positive and significant, which I am interpreting as indicating that with a change there initially is a drop in the risk of change. Then, the risk of change increases more rapidly than would have occurred simply because of the aging of the child.(time-of-duration in previous placement is measured by a "duration clock", which records the elapsed time in days since last change; it takes a value of 0 until a change, at which point it records the elapsed time since the change. If another change occurs, the clock is reset to 0 and again records the elapsed time). As I say, I would like to illustrate this effect graphically at a different duration times in foster care but can't figure out how to do it. Any suggestions would be greatly appreciated. Thanks *
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