Are ICD-9 codes valid for identifying ischemic stroke and intracranial hemorrhage among individuals with atrial fibrillation?
Administrative data using ICD-9 codes to identify stroke in AF patients is inaccurate and requires validation.
Using ICD-9 stroke and AF codes to identify patients with stroke plus AF resulted in inaccuracies. Given the expanded financial and policy implications of patient-oriented research, conclusions derived solely from administrative data without validation of outcome events should be interpreted with caution.
Thigpen et al. (Thu,) studied this question.