In clinical trials of initial breast cancer treatment, patients ordinarily remain under observation until the earliest of the following events: local tumor recurrence, distant tumor recurrence, breast cancer death, death from other causes. Or, for women who experience no events, their outcomes are all censored at the scheduled end of the study. (Some women may experience no events and withdraw from the study early--these are also censored observations. They are problematical because of potential selection bias, but that is a side-issue at the moment.) Any outcomes that might actually happen after the observed outcome, are not observed. This standard framework lends itself readily to analysis using the -stcrreg- command, which implements competing risk analysis.
I have some trial data in which some time after the end of the original study, investigators went back and determined who was alive and who dead, and whether the deaths were due to breast cancer. Notably, they did not determine whether (nor when) any recurrences happened between the time the women exited regular study observation and death. So we have a situation where the death outcomes are censored at a later time than the recurrence outcomes are. That is, in this data, we have recurrences whose observation is censored by death, but deaths are never censored by recurrence. I have been unable to figure out how to represent this in -stset- because the exit time with respect to recurrence differs from that with respect to death. For example, knowing that a woman survived until a given date and had no recurrence before some earlier date is uninformative about whether she remained at risk for recurrence throughout that interim period. Neither is it clear to me whether it is possible to analyze this data with -stcrreg- after I clear the -stset- hurdle. It sounds a bit like multiple failures, which as I understand it, -stcrreg- does not accommodate. I'm hoping somebody with more experience and a deeper understanding can clarify my thinking, or perhaps suggest an alternate approach.
I have some trial data in which some time after the end of the original study, investigators went back and determined who was alive and who dead, and whether the deaths were due to breast cancer. Notably, they did not determine whether (nor when) any recurrences happened between the time the women exited regular study observation and death. So we have a situation where the death outcomes are censored at a later time than the recurrence outcomes are. That is, in this data, we have recurrences whose observation is censored by death, but deaths are never censored by recurrence. I have been unable to figure out how to represent this in -stset- because the exit time with respect to recurrence differs from that with respect to death. For example, knowing that a woman survived until a given date and had no recurrence before some earlier date is uninformative about whether she remained at risk for recurrence throughout that interim period. Neither is it clear to me whether it is possible to analyze this data with -stcrreg- after I clear the -stset- hurdle. It sounds a bit like multiple failures, which as I understand it, -stcrreg- does not accommodate. I'm hoping somebody with more experience and a deeper understanding can clarify my thinking, or perhaps suggest an alternate approach.