Implementing a randomization consent to enable Trials within Cohorts in the Swiss HIV Cohort Study - A mixed-methods...

Area of Science:

• Clinical Trials Methodology
• Health Services Research
• Infectious Disease Epidemiology

Background:

• Trials within Cohorts (TwiCs) offers a more efficient approach to conducting randomized trials by obtaining consent for future randomization within existing cohorts.
• Implementing TwiCs requires integrating a "randomization consent" into established cohort study protocols and procedures.

Purpose of the Study:

• To describe the process of implementing the TwiCs design and randomization consent within the Swiss HIV Cohort Study.
• To evaluate participant acceptance, physician and stakeholder perspectives, and identify barriers and facilitators to TwiCs implementation.

Main Methods:

• A mixed-methods approach was employed, including analysis of cohort data, a cross-sectional survey of physicians, semistructured interviews with stakeholders, and observational data collection.
• Participant acceptance and declining rates for randomization consent were analyzed, alongside qualitative data on attitudes, barriers, and facilitators.

Main Results:

• Over 5000 participants were approached, with 57.9% accepting randomization consent, 13.8% declining, and 28.2% postponing their decision.
• Higher acceptance was associated with male sex, younger age, higher education, consistent physician care, and shorter participation time. Physicians and research staff had a positive perception of TwiCs.
• Key barriers included language, participant understanding, and time constraints, while well-trained staff and clinical integration facilitated implementation. Ethical concerns were minimal, though explicit consent was debated.

Conclusions:

• The TwiCs design and randomization consent are feasible to implement in large, existing cohort studies.
• Participant acceptance rates were high, indicating the viability of TwiCs for efficient clinical trial conduct in established cohorts.