Table 2.

Stratified analysis steps and example variables.

Goal	Example Strata Variables
(I.) Understand performance in sub-cohorts of interest	Year of diagnosis (e.g., before vs. after year x) Treatment status (treated vs. not treated) Biomarker status (positive vs. negative)
(II.) Fairness	Race and ethnicity group Gender Age group Insurance status
(III.) Risk for statistical bias in analysis	Treatment setting (Academic vs. Community) Cancer stage at diagnosis Age at diagnosis Cancer histology Smoking status Treatment status (treated vs. not treated) Biomarker status (positive vs. negative)