Optimal timing for assessing post-intensive care syndrome in clinical research: a scoping review and expert survey

Background: Since the concept of post-intensive care syndrome (PICS) was proposed, numerous studies have assessed patients and their family members. However, a wide range of assessment timings has been employed across previous studies. This study aimed to clarify how assessment timings have been implemented in existing PICS research through a scoping review, and to explore expert opinions on optimal assessment timing via an online survey. Methods: We conducted a scoping review of studies assessing PICS-related outcomes, including physical, cognitive, and psychological impairments, as well as PICS in family members. Studies were retrieved from MEDLINE, CENTRAL, and CINAHL, and screened by two independent pairs of reviewers. Eligible studies were published between January 2014 and December 2022. Studies lacking a clear description of assessment timing were excluded. We analyzed the reference point used to determine assessment schedules, the assessment time points, and their frequency. Additionally, an online questionnaire was administered to 23 members of the Japanese Society of Intensive Care Medicine PICS committee and working group members to collect expert opinions on these three aspects for clinical research. Results: A total of 657 studies were included. In prior studies, hospital discharge was the most commonly used reference point for determining assessment schedule (240 studies, 40%). However, ICU discharge was identified by experts as the ideal reference point (16 votes, 47%). The most frequently used assessment time points were 3 months (262, 23%), 6 months (212, 19%), and 12 months (206, 18%) post-discharge. Experts most commonly selected the period between 6 and 12 months as the optimal time point for assessment. While single assessments were most common in previous studies (337, 51%), experts considered three assessments to be ideal (12, 44%). Conclusions: This study revealed notable discrepancies between the assessment timing reported in previous studies and the opinions of experts regarding optimal timing. Standardization of assessment timing in PICS research is warranted to enhance methodological consistency and comparability.