odm-based study archival

ODM-based Study Archival

Jozef AertsXML4Pharma

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

XML-Signature for ODM