Assessment of Long-term Follow-up of Randomized Trial Participants by Linkage to Routinely Collected Data

Key Points Question Does follow-up of clinical trial participants by linkage to routinely collected data sources provide important insights into the long-term benefits and harms of treatment? Findings This scoping review of the published literature found only 113 trials that had been extended by record linkage. Analysis showed that some benefits of treatment extend beyond the trial, and some harms of treatment only become apparent after the trial is complete. Meaning The fate of patients after participation in clinical trials is a neglected topic, and the authors recommend that researchers routinely request permission from trial participants to study long-term treatment effects using linkage to routinely collected data.