Abstracts 77s

occurred when centers were added to the study. With 43 COMS clinical centers, there has been considerable turnover during the first 9 years of the COMS; 506 individuals (40%) have left their COMS positions. The impact of the certification program on overall operations of the COMS resource centers is not trivial; although clearly desirable for assuring the quality and comparability of data, administration of the certilication program consumes a signilicant amount of resources.

A67 DOUBLE VERSUS QUADRUPLE DATA ENTRY

Jean Maupas, Yves AIamercery, Jean-Pierre Boissel Service de Pharmacologic Clinique

Lyon, France

Double data entry (DDE) is a reliable technique to obtain hiih quality keyed data from the Case Report Forms (CRFs). We tested 2 DDE methods: 1) DDE with adjudication during the second entry and 2) DDE without adjudication followed by double entry of detected discrepancies (quadruple data entry [QDE]). The aim of this work was to estimate any quality improvement resulting from the QDE. Dedicated software was developed to support both processes.

Two experiments were performed. Fist, 390 CRFs corresponding to 40,000 items were keyed by an independent company using DDE, and by data entry operators using our software for the QDE option. We then compared the 2 resulting files byte by byte. In the 2nd experiment, 541 CRFs corresponding to 21,191 items were keyed using our software either with the DDE or the QDE option. A record of the discrepancies detected during the second entry was then analyzed. Each discrepancy was checked against the CRF by a 3-person committee. Possible adjudication related to: 1) error of the DDE without error of the QDE, 2) error of the QDE without error of the DDE and 3) error for both processes.

The results of the fust test were 105 item discrepancies: 82 errors for the DDE only, 4 errors for the QDE only and 19 errors for both. If we neglect the possibility of other errors (not detected by the file-to-fde comparison), we have (82+ 19)/40,000=0.25% error rate for the DDE and (4+19)/40,000=0.06% error rate for the QDE.

Of the 191 item discrepancies detected during the 2nd test, 144 changes were made to the correct value by both prmesses, 39 errors remained for the DDE, 2 errors for the QDE and 6 errors for both. The overall error rates were then (39+6)/21,191=0.2% for the DDE and (6+2)/21,191=0.04% for the QDE.

QDE appears to be more accurate for detecting keying errors than DDE with adjudication.

A68 RESULTS OF REKEY VERIFICATION AT THE CLINICAL CENTERS

IN THE HEMODIALYSIS (HEMO) STUDY

Jennifer Gassman, Kim Yanchar, Lata Paranandi, Martin Drabii and Gerald Beck for the HEM0 Study

The Cleveland Clinic Foutuktion Cleveland, Ohio

The HEM0 Study is a &center trial studying the impact of dose of dialysis and type of dialysis membrane on mortality and morbidity. Clinical Center (CC) study coordinators enter data into a central Oracle database. Key entry quality control is accomplished by Oracle edit check and by CC personnel keying aII data twice. The Oracle edit checks confirm that data are valid and logical and that required fields are f&d. Rekeying car-reets errors by comparing values