What are the most effective ways of collecting information from participants during a trial to improve retention?

  • “We also need to know whether & in what circumstances postal questionnaires, online questionnaires or telephone interviews are more acceptable, effective in optimising validity & response rates, and cost-effective.” (A trial methodologist)
  • “Questionnaires could be sent out following a telephone call checking if they are still willing to receive but where patients may have returned to work it can be difficult to contact people. Perhaps a book with pre filled in dates and stamped envelopes for returning questionnaires may be helpful.” (Frontline staff or other staff involved or invested in trial retention (e.g. Research Nurse, Trial Manager, regulatory or oversight role such as Sponsor or Research Director))