title: Accuracy of the ICD-9 codes for identifying TIA and stroke in an Italian automated database.
abstract: The object of this study was to evaluate the sensitivity and positive predictive value (PPV) of International Classification of Diseases, 9th revision (ICD-9) codes 430-438 in the Sistema Informativo Sanitario Regionale (SISR), an Italian health care automated database. We compared the SISR with a manual search of all cases of transient ischaemic attack (TIA) and stroke discharged from the Novara Hospital, NW Italy. Results were as follows: SISR list: 1017 patients; manual list 1005. Linked: 896; false negatives: 109; false positives: 121. Sensitivity of codes 430-438: 77% at the primary position only and 89% at either the primary or secondary position; PPV: 93% and 88%. Sensitivity and PPV for specific codes vs. each subcategory (sensitivity at the primary position only/any position; PPV at the primary position only/any position): for 430, subarachnoid haemorrhage (33/35%; 46/43%); for 431, cerebral haemorrhage (57/59%; 77/75%); for 434, cerebral infarction (35/37%; 90/87%); for 436, stroke of unknown type (29/29%; 19/16%); and for 435, TIA (75/82%; 80/78%). The SISR database has a high PPV; sensitivity is high for TIA, but low for specific stroke ICD codes.
authors.affiliation: Clinica Neurologica, Ospedale Maggiore della Carità and Università del Piemonte Orientale A. Avogadro, C.so Mazzini 18, I-28100 Novara, Italy. leomau@iol.it
authors.forename: M A
authors.initials: MA
authors.lastname: Leone
authors.forename: A
authors.initials: A
authors.lastname: Capponi
authors.forename: C
authors.initials: C
authors.lastname: Varrasi
authors.forename: R
authors.initials: R
authors.lastname: Tarletti
authors.forename: F
authors.initials: F
authors.lastname: Monaco
mesh_terms: D000368:Aged; D002561:Cerebrovascular Disorders / Q000145:classification; D016208:Databases, Factual / Q000592:standards*; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000145:classification*; D007558:Italy; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000145:classification*; D013345:Subarachnoid Hemorrhage / Q000145:classification / Q000473:pathology