1. ODM-based Study Archival
Jozef Aerts
XML4Pharma

2. 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

3. Topics Practical use of ODM for archival of clinical studies
Advantages / Disadvantages
Electronic Signatures

4. 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 ?

5. Wayne's experiences 200+ active studies 3500+ legacy CDMS archives
Spanning 15 years
Options
Formatted ASCII files
SAS XPT
CDISC ODM

6. 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

7. Study Archival Advantages of CDISC ODM
Data + metadata
Full audit trail
21 CFR 11 compliant
File linking: “chains” of files
Special features => vendor extensions

8. Study Archival Advantages of CDISC ODM
XML is very well searchable (XPath, XQuery)
Native (or mixed) XML databases

9. 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”

10. 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

11. Alternative formats SAS XPT
Legacy format
Many limitations
Very limited set of metadata
SAS software necessary
Audit trails !

12. Alternative formats PDF
Interesting for (e)CRFs
Metadata ?
Audit trails

13. 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

14. XML-Signature for ODM