ARCHIVING A COMPLEX DATASET: IST-3 A CASE STUDY by Jonathan Drever

Third International Stroke Trial “The benefits and harms of intravenous thrombolysis with alteplase within 6 h of acute ischaemic stroke” 3035 Patients from 156 Hospitals in 12 Countries Baseline, 7 Day, 6m and 18m CRFs Pre and Post Randomisation Brain Imaging

IST-3 Results Favourable shift; adjusted common odds ratio 1·27 (95% CI 1·10- 1·47), p=0·001 or, the odds of surviving with less disability were 27% greater for patients treated with rt-PA

Challenges Core Data (CRFs) Scan Housekeeping DICOM Imaging Imaging Reviews Sub- Study

Data Eccentricities Legacy Data Blinded / Startup Phase of the trial Paper Scan reads Empty fields Pre and Post Calculated Values Duplicated Data Administration Data Form sent and received dates Centre activation dates Missing Data Form version change NULL, 9 and Unknown

Documentation 1. Plain English 1. Bullet Points 1. The Devils in the Detail

Annotated Form

Form Versions

Creating a Basic Dataset Benefits Simpler to understand and analyse Cleanest most complete data Snapshots Concentrate your efforts IST-3 Dataset Up to 6m Very limited scan data Used for main trial paper and further meta-analysis More use in future…?

Archiving (Paper) Long Term store (15yrs) Resources (where?) Huge amounts of paper (114 boxes) Only 1 box was the electronic files

Archiving (electronic) Bringing it all together Investigation Cleaning Documentation Basic Dataset Archiving Catalogue All the electronic repositories Rough view of contents Points to more detail

Archiving (Technicalities)

Next Steps 2 nd Round of Archiving Further Analysis Data Sharing Updated ‘Basic Dataset’ What documentation is needed? Where will it do? (Edinburgh DataShare) Who will get access?

Take Home Messages Planning early Simple documentation Value of a basic dataset Factor in your resources Be pragmatic Its not just for Archiving