Associated factors of new subjective cognitive decline complaints after a 6-month period among community-dwelling older adults during the COVID-19 pandemic in Japan.

Background: The aim of this study was to determine the number of new subjective cognitive decline (SCD) complaints and associated factors in community-dwelling older adults during the COVID-19 pandemic in Japan.

Method: A prospective cohort study was conducted in two periods: May to June 2020, and November 2020 to January 2021. We mailed a questionnaire to 1953 older adults in the first survey, and received 700 responses in the second. We analysed 534 participants without SCD in the first survey. We collected data on sociodemographic characteristics and administered the Questionnaire for Medical Checkup of Old-Old (QMCOO) to assess respondents' health condition. SCD was operationally defined using the QMCOO as reports of (1) forgetfulness, and (2) difficulty in naming dates. The subjects were divided into two groups by their condition at the second survey: an SCD (new SCD complaints) and a no-SCD (no new SCD complaints) group.

Results: A total of 85 (15.9%) participants had new SCD complaints. The Mann-Whitney U-test and chi-squared test showed that the SCD group had significantly more risk factors of SCD: walking speed (P = 0.001), smoking (P = 0.001), and existence of person with whom the patient could consult when disordered (P = 0.002). Multiple logistic regression analysis revealed that walking speed (odds ratio (OR) = 2.115, 95% confidence interval (CI): 1.259-3.553) and the presence of person to consult (OR = 3.619, 95% CI: 1.553-8.433) were significant related factors of new SCD complaints.

Conclusion: Maintenance of physical condition and social support were associated with new SCD complaints during the COVID-19 pandemic.