Barrier (real or perceived) | Strategy |
---|---|
Patients with the opportunity to try study drug have to return to prior treatment at study completion | • Only true for phase II and earlier studies • Phase III studies should be designed with the option of a long-term extension |
Required discontinuation of current therapy during the trial run-in phase | • Consider permitting use of and incorporating a higher/loading dose of the study drug to offset potential reduction in exposure owing to prior/concomitant medications • Implementation of a downtitration and uptitration algorithm of concomitant medications and study drug, respectively |
Change in diagnosis from TN to other types of TN • The TN phenotype is also known to change over time, with potential for remission [22], which could alter whether patients meet pain requirements | • Recruitment of patients with recent visits to the clinic versus database records |
Only specialists are recruiting patients attending specialist clinics | • Local primary care practices could be encouraged to telephone potential patients ○ A nurse could administer a semistructured questionnaire to identify potential cases for referral to the specialist center |
Prescreening eligibility and screening failures inconsistently captured | • Implementation of a central project management and coordination system with prescreening and screening data locks that are promptly reviewed |
Patient diary too large a burden | • Patient diaries less onerous (e.g., by not requiring documentation of all individual attacks, but rather average daily pain, or not requiring documentation of each attack after a certain threshold (e.g., > 20 attacks)) |
Lack of time or inability to attend study visits owing to distance/mobility | • Replace some onsite visits with telephone visits • Consider patient compensation for time loss and/or travel/dietary expenses |