Daily Living Subjective Cognitive Decline Indicators in Older Adults with Depressive Symptoms: A Scoping Review and Categorization Using Classification of Functioning, Disability, and Health (ICF)

Subjective Functional Difficulties Were Associated With Subjective Cognitive Decline Among U.S. Older Adults: Mentally Unhealthy Days Mediation and Income Level Moderation Effects

Introduction

Subjective cognitive decline (SCD) is a self-perceived decline in cognition that may progress to mild cognitive impairment or Alzheimer's disease. SCD may be associated with difficulties in daily functioning and psychological distress. Previous research has shown the association between functional difficulties and SCD via mentally unhealthy days (MUDs). However, whether income levels influence the mediation effect of MUDs is less understood.

Objectives

This study examined the association between subjective functional difficulties and the odds of SCD through MUDs, and whether the mediation effect was moderated by income levels.

Methods

Cross-sectional data were obtained from the 2019 Behavioral Risk Factor Surveillance System (N = 13,160 older adults aged 65+; 7,370 women). SCD was assessed by more frequent or worse memory loss and confusion in the past 12 months. Subjective functional difficulties represented difficulties with daily activities. MUDs denoted the days that a person felt mentally unwell within the past 30 days. We used path analysis with 5,000 bootstrapped confidence intervals and logistic regression to classify the risks of SCD based on subjective functional difficulties and MUDs.

Results

Subjective functional difficulties were positively associated with SCD through mediation by MUDs (b = 0.119, 95% CI 0.102, 0.137). After accounting for covariates, we found that greater subjective functional difficulties were associated with 2.50 times the odds of SCD (AOR = 2.50; 95% CI: 2.14, 2.91); MUDs were related to 1.06 times the odds of SCD reporting (AOR = 1.06; 95% CI: 1.05, 1.07). Income levels moderated the indirect effect of MUDs in the subjective functional difficulties-SCD relationship, with an income of <$15,000 showing the most prominent effect. Those earning ≥$50,000 self-reported a lower SCD than those earning <$15,000.

Conclusions

Our study extends previous findings by demonstrating that greater subjective functional difficulties are associated with higher odds of SCD through more frequent MUDs, with higher income levels being associated with more SCD reporting.

Subjective Aging Difficulties among Older Adults with Subjective Cognitive Decline

In older adults, subjective cognitive decline (SCD) may progress to an early stage of dementia. Yet, its association with subjective daily functional difficulties in aging is less well studied by experiences of mentally unhealthy days (MUDs). Employing a cross-sectional design approach, we analyzed the Behavioral Risk Factor Surveillance System dataset on 7429 older adults with SCD (aged 65 to >80, 45% males, 55% females) to explore SCD in instrumental daily activities of living (SCD-IADLs) and healthcare access mediation by MUDs and moderated mediation by age cohort, controlling gender and education. The bias-corrected percentile bootstrap with 5000 samplings revealed that MUDs partially mediate the relationship between SCD-IADLs and healthcare access, with a 28.2% mediating effect. Age cohort moderated the relationship between healthcare access and MUDs, MUDs and SCD-IADLs. Specifically, the predictive effects from healthcare access to MUDs and MUDs to SCD-IADLs were more profound in the 70-74 age cohort.

Subjective Functional Difficulties and Subjective Cognitive Decline in Older-Age Adults: Moderation by Age Cohorts and Mediation by Mentally Unhealthy Days

Background and Objectives: Despite the expected positive association between subjective functional difficulties (SFD) and subjective cognitive decline (SCD), their mediation by mentally unhealthy days (MUDs) is under-studied. Moreover, few SCD studies have examined affective reactivity to functional difficulties by age cohort. This study examined the mediation effect of MUDs on the association between SFD and SCD by age cohorts' moderation among older adults. Methods: Using a cross-sectional design approach, we used the 2019 BRFSS dataset on 13,377 older adults aged 65 to ≥80 (44% males and 56% females). Results: The bias-corrected percentile bootstrap with 5000 samplings revealed that MUDs partially mediate the relationship between SFD and SCD (14.12% mediation effect), controlling depressive symptoms, education, income levels, and race. Age cohorts moderated the relationship between SFD and SCD and between SFD and SCD but not between MUDs and SCD. The predictive effects of the path from SFD to MUDs and from MUDs to SCD were stronger in the younger-old (65-69) than the middle-old (70-79) and oldest-old (≥80) age cohorts. Worse SCD was associated with being Asian, in female older adults, and in those with lower education and income levels. Conclusions: These findings extend the chronic stress theory predictions that accentuated emotional vulnerability to subjective functional difficulties may magnify SCD, particularly in the younger-old age group. By implication, preventive SCD interventions should seek to support younger-old adults in their activities of daily life for successful aging transitioning into older-age cohorts.