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 Archival Advantages of CDISC ODM Data + metadata Full audit trail 21 CFR 11 compliant File linking: “chains” of files Special features => vendor extensions
Study Archival Advantages of CDISC ODM XML is very well searchable (XPath, XQuery) Native (or mixed) XML databases
Study Archival Disadvantages 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 formats SAS XPT Legacy format Many limitations Very limited set of metadata SAS software necessary Audit trails !
Alternative formats PDF Interesting for (e)CRFs Metadata ? Audit trails
Electronic Signatures and 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
XML-Signature for ODM