Implementation of subjective cognitive decline criteria in research studies

TLDR

Subjective cognitive decline (SCD) is an early marker of preclinical Alzheimer's disease and has been defined by the SCD‑I as a research criterion to identify individuals for early intervention trials. The study aims to address assessment and implementation issues to enable the application of SCD research criteria. The authors convened the SCD‑I working group to identify, discuss, and refine operationalization topics for SCD criteria in research settings. The group identified key operational topics—SCD inclusion/exclusion criteria, informant involvement, and demographic influences—and proposed harmonized recommendations for SCD measurement across studies.

Abstract

Abstract Introduction Subjective cognitive decline (SCD) manifesting before clinical impairment could serve as a target population for early intervention trials in Alzheimer's disease (AD). A working group, the Subjective Cognitive Decline Initiative (SCD‐I), published SCD research criteria in the context of preclinical AD. To successfully apply them, a number of issues regarding assessment and implementation of SCD needed to be addressed. Methods Members of the SCD‐I met to identify and agree on topics relevant to SCD criteria operationalization in research settings. Initial ideas and recommendations were discussed with other SCD‐I working group members and modified accordingly. Results Topics included SCD inclusion and exclusion criteria, together with the informant's role in defining SCD presence and the impact of demographic factors. Discussion Recommendations for the operationalization of SCD in differing research settings, with the aim of harmonization of SCD measurement across studies are proposed, to enhance comparability and generalizability across studies.