PROC LIFETEST is run with the STRATA= statement to compare survival curves between two treatment arms. By default, which test does PROC LIFETEST report?
Select an answer to reveal the explanation.
Short Explanation
Here's the deal — when you run PROC LIFETEST with STRATA=, it gives you the log-rank test by default. You get a test that weights all time points equally, which is most powerful when the hazard ratio stays constant over time.
Full Explanation
PROC LIFETEST produces the log-rank test by default when STRATA= is specified. The log-rank test weights all time points equally and is most powerful when the hazard ratio is constant (proportional hazards) over time. The two-sample t-test on observed survival times including censored observations is wrong because t-tests are not valid for censored survival data. The Wilcoxon test that gives more weight to early failure times is wrong because it requires TEST=WILCOXON to be specified. The likelihood ratio test from a parametric survival model is wrong because likelihood ratio tests come from PROC PHREG or PROC LIFEREG.