APPENDIX 1

International Classification of Diseases, Ninth Revision (ICD-9) Diagnosis Codes Used in Electronic Database Search

ICD-9 CodeCategory
287.0Allergic purpura
287.1Qualitative platelet defects
287.2Other nonthrombocytopenic purpura
287.3Primary thrombocytopeniaa
287.4Secondary thrombocytopeniab
287.5Thrombocytopenia, unspecified
287.8Other specified hemorrhagic conditions
287.9Unspecified hemorrhagic conditions
  • a Includes primary thrombocytopenia, unspecified (287.30), immune (idiopathic) thrombocytopenic purpura (ITP) (287.31), other primary thrombocytopenia (287.39) and congenital and hereditary thrombocytopenias.

  • b Includes thrombocytopenia caused by dilution, drugs, extracorporeal circulation of the blood, and platelet alloimmunization.