Table 1. Steps in data verification and the responsible parties.

Steps in the data verification process	(Intended) result	Implementation/responsibility
1. Coordination and support	A coordinated verification process	DICA data verification department
2. Patient and variable selection	Verification items and criteria	Data verification committee
3. Inviting and selecting hospitals	Random sample of hospitals to audit	DICA data verification department
4. Training of data managers	Competent data managers	DICA and scientific committee
5. Providing patient lists and access to (E)PR	List with all patients possibly fulfilling inclusion criteria	Hospitals
6. Providing hospital audit data on a secured laptop	A web-based survey prefilled with registered data by the hospital	MRDM
7. Actual data verification	Results on variable level: ‘not-discrepant’ or ‘discrepant’	Independent data managers
8. Analysis and processing of results	Discrepancy report	DICA data verification department
9. Interpretation and response to discrepancies	Updated discrepancy report	Hospitals
10. Final conclusion	Final report and conclusions	Data verification committee

(E)PR, (electronic) patient records; MRDM, medical research data management.