Outcomes
The primary effectiveness outcome was a composite of ischemic stroke or
systemic embolism (SE) and all-cause mortality. The primary safety
outcome was a composite of major bleeding, defined as either
intracranial hemorrhage, gastrointestinal bleeding, or major bleeding
from other sites. The individual components of the safety and
effectiveness outcomes were evaluated in a secondary analysis.
We identified the outcomes by screening the ICD-9 or ICD-10 codes for
the primary diagnosis on inpatient claims (Supplementary Table S1). In
earlier validation studies, these codes performed relatively well and
gave positive predictive values of over 80%.32,33