Assessing the quality of information recorded on trial registries

Tags: Poster
Nurbhai M, Grimshaw J, Lorenzo Moja P, Liberati A, Chan A, Dickersin K, Krezla-Jeric K, Moher D

Background: In 2004 all ICMJE member journals agreed to adopt a trial registrations policy as one solution to publication bias. The value of trial registries (TRs) has been well established and is supported by funding and government agencies. Yet there is little focus on the type and completeness of data in existing TRs.

Objective: Our objectives were to, i) determine the type of data recorded in TRs, ii) assess their quality, iii) compare structure and content of different TRs, and iv) to identify optimal data structures for them.

Design: In January 2005, a random sample of trial records was extracted from three international TRs ClinicalTrials.gov, NCI's PDQ Database and ISRCTN Register. No restrictions were placed on trial status, design or medical area, although some TRs adopted inclusion criteria. Records were assessed using a quality checklist consisting of 30 desirable items grouped into five categories, identifying information, trial details, funding, contact details and data collection forms.

Results: A pilot study assessing 45 records (15 from each register) was undertaken. The overall quality was poor (median: 16 range: 10-22 items completed per record) and varied considerably across TRs. ClinicalTrial.gov (median 17) and NCIPDQ (median 18) faired better than ISRTCN (median 13) (ClinicalTrial.gov vs. NCIPDQ p=0.79; ClinicalTrial.gov vs. ISRTCN p<0.001; NCIPDQ vs. ISRTCN p<0.001). Records fell short of providing complete data in the category of trial details (items: primary outcome; key trial dates) and contact details (items: full address; fax). A copy of the study data collection form was not included in any record. Results from the definitive study will be available for presentation.

Conclusions: Although our quality criteria were not stringent, the preliminary results show considerable variation in the data available in current TRs and an unsatisfactory quality of desirable requirements for trial protocols. The results suggest that there is room for standardization of the type of data recorded in TRs to provide better and more complete essential public information.

Other co-authors Ivan Moschetti; Drummond Rennie; Ida Sim; Jimmy Volmink