Experimental Drug Efficacy

Researchers interested in the effectiveness of a new tumor suppression medication recorded time to tumor for cancer patients. Forty-three patients were treated with an older drug (A) and 76 were treated with the new drug (B).

The survival functions cross:
LogRankTest does not detect a significant difference in the underlying hazard rates:
Suppose researchers expected that the new drug is more effective at preventing late-developing tumors. The following FlemingHarrington weights emphasize late survival times:
LogRankTest weighted for late survival detects a significant difference: