Fig. 1

Study design and exposure assessment. Medication use was ascertained in the time period from 6 months after primary breast cancer diagnosis through metastatic diagnosis, which occurred from 2009 to 2016. Time to metastasis was calculated from 6 months following primary diagnosis through date of metastatic diagnosis. Survival time was calculated from 6 months following primary diagnosis through date of death or administrative censoring on December 31, 2016