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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
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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