Background: The New York Patient Occurrence and Tracking System (NYPORTS) is a mandatory adverse event reporting system that was redesigned in 1998. Analysis of the first full year of its use showed large regional and hospital variation in reporting frequency not due to hospital or case mix differences. In early 2001, New York State mandated that all hospitals conduct retrospective review for unreported adverse incidents for the previous 2 years. Hospitals could submit previously unreported incidents within a defined window without penalty. The hospital used an ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification) analysis to screen for missed NYPORTS cases, to assist in focusing review resources.
Methods: NYPORTS categories were matched to corresponding combinations of inpatient ICD-9-CM diagnosis and procedure codes. Other variables considered included discharge disposition, primary or secondary coding position, readmissions, and NYPORTS exclusions.
Results: Among more than 60,000 discharges in 2 years, 5,500 records were identified for NYPORTS review based on the ICD-9-CM criteria; 211 cases had already been reported through normal reporting processes. Thirteen of the NYPORTS codes had a 30% or greater match rate to the ICD-9-CM codes, with an average "hit rate" of 56%. Five-hundred sixty reviews identified 187 (33.4%) reportable events for the same code the case was being screened for and 26 additional reportable events for a code other than the screening code. NYPORTS categories for procedure and operative-related occurrences had the highest yields.
Conclusions: This retrospective effort helped identify previously unreported occurrences, increase institutional awareness of New York State's mandatory reporting process, and stimulate the redesign of our concurrent detection process.