Accuracy of the patient identifier in a family practice data system

The accuracy of a general practice data system has been measured and has improved considerably over three years. It is difficult to identify all the factors contributing to this change, but an overall effort to emphasize the importance of recording patient identifiers correctly has been effective. No directly comparable error rates have been reported elsewhere; consequently, relative accuracy cannot be known. Administrators and managers of data systems are urged to determine levels of error and disseminate this information.