Synchronising Diversely Implemented Databases to Support Administration of Clinical Research

Synchronising Diversely Implemented Databases to Support Administration of

Clinical Research Stuart AndersonMark HartswoodConrad Hughes

CRISP (Clinical Research Information Systems Project)School of Informatics

University of Edinburgh

Many administrative databases,much the same data

ResearchOrganisation



NHSR&D

Project R#30Title “A very important study”…


Share the data automatically!




NHSR&D



Research organisations

• Research Organisations (ROs) in NHS Lothian administering clinical research projects:– NHS Research & Development Office– Welcome Trust Clinical Research Facility (WTCRF)– Scottish Cancer Research Network (SCRN)– Experimental Cancer Medicine Centre (ECMC)

• NHS R&D involved in all projects, at least in terms of handling approvals

Project meta-information

• Project title• Project start and end dates• Project ethics status and research approval• Project sponsors, funders and finance data• Project personnel• Sponsor and personnel contact details• Patient lists and activity records• …

Supposedly the same data, but in different databases

A CRISPy Opportunity

• We could:– Reduce data entry costs– Improve data quality – Improve awareness of activity

• ...if we find ways to share common data between databases

• Suits government “bureaucracy busting”

Options

• Looked at commercial solutions:– Some didn’t understand the complexity and

risks (e.g. rsync in two directions)– Competent-sounding ones were prohibitively

expensive (e.g. £170k per site)

• Our solution: DIY approach using free software

Harmony

• Document synchronisation framework– By Benjamin Pierce et al.:

http://www.seas.upenn.edu/~harmony • Reconciles changes made to multiple

disconnected structured documents containing the same data (or subsets thereof - the “view update” problem), e.g.– Internet browser bookmarks files– Calendar applications

• Strong theoretical approach with emphasis on provable safety: changes only propagated under well-defined circumstances

Overview of Harmony

RO1’sDocument

X

RO1’sDocument

XRO2’s

DocumentX

RO2’sDocument

X

Harmony

Log of changes

and conflicts

Log of changes

and conflicts

New Archive

New Archive

Archive(~Old X)

Archive(~Old X)

Updated DocumentX (RO1)

Updated DocumentX (RO1)

UpdatedDocumentX (RO2)

UpdatedDocumentX (RO2)

Harmony operation: Equality

Archive RO1’s Document X RO2’s Document X

<project> <rd_id>R#30</rd_id> <title>A very important study</title> <ethics>yes</ethics> </project>



After running Harmony:

New Archive New Document X (RO1) New Document X (RO2) Log




“Documents are equal”

Harmony operation: Changes


<project> <rd_id>R#30</rd_id> <title>A very important study<title> <ethics>no</ethics> </project>

<project> <rd_id>R#30</rd_id> <title>A very important study<title> <ethics>yes</ethics> </project>

<project> <rd_id>R#30</rd_id> <title>A very very important study<title> <ethics>no</ethics> </project>

After Running Harmony:New Archive New Document X (RO1) New Document X (RO2) Log

<project> <rd_id>R#30</rd_id> <title>A very very important study</title> <ethics>yes</ethics> </project>


<project> <rd_id>R#30</rd_id> <title> A very very important study </title> <ethics>yes</ethics> </project>

“Project R#30: title change propagated from RO2 to RO1; ethics change propagated from RO1 to RO2”

Harmony operation: Conflict


<project> <rd_id>R#30</rd_id> <title>A very important study<title> <ethics>yes</ethics> </project>

<project> <rd_id>R#30</rd_id> <title>A very unimportant study</title> <ethics>yes</ethics> </project>


After Running Harmony:New Archive New Document X (RO1) New Document X (RO2) Log


<project> <rd_id>R#30</rd_id> <title>A very unimportant study</title> <ethics>yes</ethics> </project>

<project> <rd_id>R#30</rd_id> <title>A very very important study</title> <ethics>yes</ethics></project>

“Project R#30 conflict over title fields – R#30 title changes not propagated”

Conflicts

Id Field NHS R&D WTCRF

E06377 Project titleGlobal Registry of Acute Coronary Events (GRACE)

GRACE: Global Registry of Acute Coronary Events

E01058 Project titlePROCARDIS (Precocious Coronary Artery Disease) study

PROCARDIS - Precocious coronary artery disease study - a study to identify inherited causes of heart disease

E01033 Project titleVITATOPS: a randomised controlled trial of vitamins to prevent stroke.

Vitatops: A randomised controlled trial of vitamins to prevent sroke.

600 pre-roll-out conflicts to resolve; these examples are fairly trivial

Provenance issues?

• Trust

• Alignment

• Form and meaning

• Authority

• Control

Trust

• Organisations are allowing other participants to write to their databases

• Do you trust them?– Alignment of goals– Need to establish confidence in each other’s

procedures and practices– Established through regular meetings– Others might know more than you do

Alignment: record identity

• Need to identify which records in different databases refer to the same project, funding body or person

• Use R&D Number, assigned by NHS R&D, for projects– Creation complicated because projects may initially

be entered (without R&D#) by ROs– Deletion complicated because some projects may

leave scope but no projects should really be deleted• Funding bodies and persons are handled more

loosely– Identity and duplication less critical here

Establishing identity

Syncing two database tables

SK SK

Database 1 Database 2

7

3

79

9

3

Unique Shared Keys identify records across databases

Synchronising tables across two databases depends on having a unique shared key. This value has to be guaranteed to be unique within each table, and to identify corresponding records uniquely across databases.

Do they have the same meaning?

• Start/end date– Approval? Funding? Recruitment? Analysis?– Often driven by reporting requirements

• Some fields too contentious, not useful to share, so not included in sync– Option to synchronise separate meanings as separate

fields

• Get parties to agree on common meanings– Valuable communications exercise among

participants

Shared meaning = shared form?

• Field types/sizes• Field values

– N/A na None No Pending– Funder classification varies from DB to DB

• Personnel roles– One column per role or one row per role?

• Some adjustment and convergence possible to participants’ databases

• Transform data to “standard” on export/import

Authority

• Harmony is symmetric: no peer to a sync gets priority• Some information should only be sourced by R&D

(responsible for approvals)• Some information is best sourced by ROs (personnel,

funding)• But:

– Databases involved don’t record sources of information– Strict rules impair usability and make for an unpopular (and

unused) system

• Solution:– Emphasise audit over control– But provide limited inter-site control at data import stage

Control

• Each database contains organisation-specific (and private) information

• Some content is just irrelevant to others

• Some patient data!

• Solution: import/export script run locally by each organisation only exports a chosen subset of tables, rows and columns

Benefits

• Data only entered once for all

• Everyone takes responsibility for data they’re most expert in

• Disagreement (“conflict”) is permitted, and may be resolved through human-human communication

• Limited (inter-site) audit operating so expect/hope for responsible behaviour

Conclusion

• Real data synchronisation application has been far from the theoretical ideal– Issues of alignment, scope, identity, policy, trust, data

quality, form and meaning

• Solutions to problems encountered aren’t just technical: organisational engagement and trust have been essential in keeping the task tractable

• Rolling out now, so reality yet to be seen– Depends on fair balance of effort and reward among

participants

Thank you!

[email protected]

School of Informatics

University of Edinburgh

mailto:[email protected]