Automated review of blood donor screening test patterns at a regional blood center

Regional blood centers recently increased the number of tests used to protect transfusion recipients from infectious disease. The Food and Drug Administration has noted that computer systems for managing these data have lost donor data or failed to recognize all deferrals. Of 118,396 consecutive donations, including 4,859 records with at least one positive test result, records were analyzed to determine the number and frequency of distinct combinations of test data. A modular precedence-logic expert system assigned donor deferrals and unit dispositions. Ten combinations of data accounted for 4,334 records (89%); the remaining 525 records (11%) were distributed among 85 combinations of test data. The expert system correctly assigned all records. Regional blood centers must interpret a growing number of test results, including donations with a complicated pattern of multiple positive screening test results. The distribution of these data is described and the expert system's ability to monitor deferrals and ensure database completeness is demonstrated.