Should the perspective of subjective memory decline differ between cognitively unimpaired individuals and their informants? Baseline results of the BRASCODE Cohort

Abstract Background Subjective Cognitive Decline (SCD) is characterized by cognitive complaints in cognitively unimpaired (CU) individuals. Its condition displays considerable heterogeneity etiologies, including neurodegenerative diseases. Our aim is to compare the memory complaints between patients with SCD and their informants in the BRASCODE cohort. Method The BRASCODE cohort includes CU individuals aged >65 presenting memory complaints and at least one SCD‐plus criteria. The MCS was held separately with both participants and informants. Additionally, baseline sociodemographic and Mini Mental State Examination (MMSE) data were held. Participants and informant’s concordance regarding patients' memory complaints was assessed using the MCS scale. If both answers were ≥ 7, there was concordance. The continuous variables were described as median (interquartile range, IQR) and categorical variables as frequencies. Scores of the MCS scale ranges from 0 to 14, with scores ≥ 7 indicating complaint; and were compared using Spearman’s rho and Mann‐Whitney test. Result Data were collected between March‐2022 and December‐2023. 143 SCD patients were included (mean age = 69; 72.2% female). The median MCS‐patient and MCS‐informant was 8 and 5, respectively. The patients have a median of 3 SCD‐plus criteria, most with complaints at age ≥ 60 and with concerns regarding memory. The SCD‐patient scale correlated negatively with patient age (rho = ‐0.244; p = 0.003) and positively with informant’s SCD scale (rho = 0.305; p = 0.0002), but not with patient education nor with MMSE results. Most participants (86, 60.1%) and their informants' perceptions disagree about patients' memory decline. The participants in the group with concordant MCS scores had lower education (11 vs 16) and were more balanced in relation to sex (32 [56.1], 71 [82.6]) than the group with discordante responses. The patients' age and MCS were not different between the groups. Conclusion The baseline results show that most dyads disagreed regarding participants' memory decline. In addition, the presence of informant perception of decline may be a risk factor for a future cognitive decline. The AD biomarkers analysis as well as one and two‐year follow‐ups may yield valuable insights into the correlation between patients' and informants' reported complaints.