Use of a medical center's computerized health care database for notifiable disease surveillance

The sensitivity of a medical center's inpatient and outpatient database to detect notifiable diseases was examined. Only 53 percent of inpatient and 7 percent of outpatient laboratory-confirmed cases of shigellosis, salmonellosis, giardiasis, and hepatitis were identified by an automated search for matching diagnosis codes. Reasons for lack of sensitivity include nonavailability of laboratory results at the time of diagnosis assignment, use of a standardized encounter form with limited preselected diagnosis codes, and pre-emptying of the infectious disease diagnosis by other diagnoses.