Table 2.

Considerations related to use of data linkage in clinical trials.

Advantages	Disadvantages	Other considerations
• Low burden on participants and trial sites	• Endpoints limited to those captured in the data source. Complex clinical, performance-based, and imaging measures often not captured	• Participant consent
• Comparatively low cost to primary data collection	• Endpoints need to be validated and may not be available across all jurisdictions of interest	• Nature of linkage (probabilistic or deterministic)
• May minimize selection bias and loss to follow-up if all participants in prior trial agree to participate 51	• Healthcare use may differ due to participant characteristics unrelated to the intervention	• Completeness and accuracy • Timing of extensive phase relative to parent trial
• Can establish external comparator group 52		• Availability of standardized definitions for variables to be used 53
• Ability to capture outcomes non-traditional outcomes such as admission to long-term care and use of social services		• Time and administrative burden of data access and regional variation in access processes