OBJECTIVES: Endpoints derived from diaries have been used in clinical trials for medical product development for more than 25 years. Use of diaries to collect patient reported outcome (PRO) data in clinical trials enables assessment of day-to-day fluctuations in disease symptoms and impacts, and for PRO events to be captured when they occur. This review aimed to examine how diaries are used to support Food and Drug Administration (FDA) approval of new products.
METHODS: New molecular entities approved by the FDA between 2019 and 2023 were identified. The corresponding label and review documents were examined to extract information pertaining to PRO diary use in pivotal trials, relevant reviewer comments, and any labelling language referencing the PRO(s) assessed via the diary.
RESULTS: Diaries were used to collect PRO data for 15% (n = 37) of 241 drugs approved by the FDA between 2019 and 2023. Over a third of approvals with diary-based data in the pivotal trials were for diseases of the nervous system (n = 15/37, 41%; 8 unique diseases). Diaries were used to collect data for a primary endpoint in approximately half of the products (n = 21/37, 57%) and for one or more key secondary endpoints in most products (n = 33/37, 89%). Where data collection mode was reported, use of an electronic diary was most common (n = 21/24, 88%). Diary-based PRO concepts were included in the label for 30 of 37 products (81%) supported by trials with diary data.
CONCLUSIONS: The ability to complete diaries in real-time with electronic or paper methods reduces recall bias and is ideal for therapeutic areas with day-to-day, event-based, or episodic fluctuations that require repeated measurement.
