Randomized Comparison of Morning Versus Bedtime Administration of Aspirin: A Cardiovascular Circadian Chronotherapy (C3) Trial

The study is a pragmatic, registry-based, open-label, randomized controlled trial combining the utilization of the Danish nationwide health registries and the official Danish electronic letter system (Digital Post/eBoks) into an innovative, decentralized trial requiring no study visits from participants. The nationwide health registries will be used for identification of potential participants and data collection, including baseline information and follow-up data, while the electronic letter system will be used for sending recruitment letters and communicating with participants. Study participants will provide electronic informed consent from home before inclusion and randomization.

The trial will include patients currently in aspirin treatment regardless of the presence or absence of established cardiovascular disease. Participants will be randomized 1:1 to either aspirin administration at bedtime or in the morning. The trial is event-driven.

Inclusion criteria

• Age >=18 years
• Current chronic treatment with aspirin (as recorded in the Danish National Prescription Registry and confirmed by the participant via questionnaire)
• Signed informed consent

Exclusion criteria

• There are no exclusion criteria for this trial