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Learn about the practical use of CDISC ODM for archival of clinical studies, including advantages like full audit trail and disadvantages such as file size issues. Discover best practices for ODM archival, file chaining, and electronic signatures.
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ODM-based Study Archival Jozef Aerts XML4Pharma
History of the work • February 2008: TMF asks to write an expert opinion (“Gutachten”) on the use of ODM for study archival • June 2008: first draft • February 2009: final version
Topics • Practical use of ODM for archival of clinical studies • Advantages / Disadvantages • Electronic Signatures
Practical use of ODM for Archival • Many EDC vendors archive as ODM + CRFs as PDF • Only 1 extensive “experience report” CDISC Interchange Paris 2005: W.Kubick:“Case Study: Applying CDISC Standards to replace a Legacy CDMS” • What are the best practices ?
Wayne's experiences • 200+ active studies • 3500+ legacy CDMS archives • Spanning 15 years • Options • Formatted ASCII files • SAS XPT • CDISC ODM
Wayne's experiences • 13 months of planning, design, building and validating tools • Actual archival: • 8 months (planned: 12-18) • 5 staff (planned: 7) • Major issues • Metadata were missing • Audit trail reconstruction
Study ArchivalAdvantages of CDISC ODM • Data + metadata • Full audit trail • 21 CFR 11 compliant • File linking: “chains” of files • Special features => vendor extensions
Study ArchivalAdvantages of CDISC ODM • XML is very well searchable(XPath, XQuery) • Native (or mixed) XML databases
Study ArchivalDisadvantages of CDISC ODM • File size • Same data in SAS XPT has half the size • When zipped: 30% difference • Compression factor: ~50 • Best practice: one file per subject • Visual presentation is lost • Use ODM “ArchiveLayout”
ODM Archival Best Practices • 1 file per subject • File chaining using “FileOID” and “PreviousFileOID” • Metadata / ReferenceData in separate file or in each file • Vendor extensions • XML-Signature
Alternative formatsSAS XPT • Legacy format • Many limitations • Very limited set of metadata • SAS software necessary • Audit trails !
Alternative formatsPDF • Interesting for (e)CRFs • Metadata ? • Audit trails
Electronic Signaturesand ODM • XML files (but also sections of them) can be signed using XML-Signature • Signature is XML itself and can reside within the XML file • Uses electronic certificates • New evolution: XAdES • Complies to European law • Extends XML-Signature