Optimising patient recall of adverse events over prolonged time periods

Objectives Large, simple, pragmatic, low-risk, maintenance treatment trials may seem straightforward to design, run and analyse. However, if trial case record forms (CRFs) are completed infrequently, the reliability of patient recall over these long time-periods is questionable, especially when recording individual incidences and severity of toxicities of specific interest to the trial. It is essential to know these detailed toxicities as it forms an indication of the reduced level of exposure when comparing treatment duration in a non-inferiority trial. Optimal methods of achieving accurate data are required.