Purpose: Understand the choice of recall period for PRO measures based on intended use, characteristics of the disease, treatment, and attributes of studies.
Methods: Current practice and considerations were reviewed within several disease areas (overactive bladder, menopausal hot flashes, niacin-induced flushing, osteoarthritis pain, irritable bowel symptoms, benign prostatic hyperplasia, and alopecia).
Results: Rationales were identified for using different recall periods, including event-driven (immediate), daily, up to weekly, and longer than weekly. This work demonstrates that (1) recall depends on what the PRO measure captures, its intended use, and attributes of the disease and study; (2) within the same disease area, recall can vary depending on the concept or phenomenon of interest; (3) recall must consider patient burden and their ability to easily and accurately recall the information requested; and (4) recall must be consistent with the duration of the trial and the scheduled clinic visits.
Conclusions: Shorter recall periods may underestimate symptom burden when symptoms have diurnal or day-to-day fluctuation and may place undue burden on patients. On the other hand, recall intervals that are too long may either over- or underestimate the health state. Therefore, appropriate criteria should be considered given attributes of the disease when selecting an adequate recall period.
