Table 1.

International Classification of Disease, Ninth Edition, Clinical Modification (ICD 9‐CM) Codes Used to Define Study Outcomes

Primary Outcome	ICD‐9‐CM Codes
Major bleeding
Gastrointestinal bleeding	456.0, 456.20, 530.21, 530.7, 530.82, 531.0x, 531.2x, 531.4x, 531.6x, 532.0x, 532.2x, 532.4x, 532.6x, 533.0x, 533.2x, 533.4x, 533.6x, 534.0x, 534.2x, 534.4x, 534.6x, 535.01, 535.11, 535.21, 535.31, 535.41, 535.51, 535.61, 535.71, 537.83, 537.84, 562.02, 562.03, 562.12, 562.13, 568.81, 569.3, 569.85, 578.x
Nontraumatic intracranial hemorrhage	430, 431, 432.x
Traumatic intracranial hemorrhage	852.x, 853.x
Bleeding from other sites	423.0, 459.0, 596.7, 599.71, 719.1x, 784.8, 786.3
Stroke
Ischemic stroke	433.x1, 434.x1, or 436
Transient ischemic attack (TIA)	435.X
Systemic embolism	444.x

Outcomes were identified using primary or secondary diagnosis on inpatient claims. When assessing ischemic stroke, TIA, and systemic embolism, we excluded the events that had a primary discharge diagnosis of rehabilitation (ICD‐9‐CM code V57) or any additional diagnoses of subarachnoid hemorrhage (ICD‐9‐CM code 430), intracerebral hemorrhage (ICD‐9‐CM code 431), or trauma (ICD‐9‐CM codes 800–804 and 850–854). When assessing major bleeding, we excluded the events that had a primary discharge diagnosis of rehabilitation (ICD‐9‐CM code V57).