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Flow diagram for cohort development. Cohort generation query was performed 09/08/2017. Note that if a subject had the diagnosis code used as an outpatient only and for a duration <30 days, the diagnosis code use was considered a “Rule Out” use and the subject was excluded (see reference 19). CDW: corporate data warehouse; ICD-9: International Classification of Diseases 9th version; PH: pulmonary hypertension.
