ERBB2 and cerebrovascular disorder: Individuals assigned to the strategy their data are compatible with, and assignment assumed to be randomized within levels of the baseline covariates (age, year of baseline, time from diagnosis, stage at diagnosis, T classification, N classification, grade, HER2 status, side, chemotherapy, radiotherapy, antibody treatment, cerebrovascular disease, diabetes, COPD, cardiovascular disease, anticoagulants, antidepressants, NSAIDs, opioids, hormone replacement therapy, marital status, education status, and employment status).a