Positive predictive value of ICD-9th codes for upper gastrointestinal bleeding and perforation in the Sistema Informativo Sanitario Regionale database

We identified patients whose records in the Sistema Informative Sanitario Regionale database in the Italian region of Friuli-Venezia Giulia showed a code of upper gastrointestinal bleeding (UGIB) and perforation according to codes of the International Classification of Diseases (ICD)-9th revision. The validity of site- and lesion-specific codes (531 to 534) and nonspecific codes (5780, 5781, and 5789) was ascertained through manual review of hospital clinical records. The initial group was made of 1779 potential cases of UGIB identified with one of these codes recorded. First, the positive predictive values (PPV) were calculated in a random sample. As a result of the observed high PPV of 531 and 532 codes, additional hospital charts were solely requested for all remaining potential cases with 533, 534, and 578 ICD-9 codes. The overall PPV reached a high of 97% for 531 and 532 site-specific codes, 84% for 534 site-specific codes, and 80% for 533 lesion-specific codes, and a low of 59% for nonspecific codes. These data suggest a considerable research potential for this new computerized health care database in (C) 1999 Elsevier Science Inc.