Objective:

To systematically review and synthesize the factors influencing subjective cognitive decline (SCD) in older adults based on the Health Ecological Model (HEM), emphasizing its significance in understanding SCD and providing direction for future research.

Key Findings:

• 33 articles were included, with sample sizes ranging from 212 to 74,472 participants, highlighting the diversity of SCD experiences.
• Factors influencing SCD were categorized into four dimensions: personal characteristics, behavioral characteristics, interpersonal networks, and living and working conditions, which have implications for targeted interventions.
• None of the studies addressed the policy environment dimension, indicating a significant research gap that needs to be explored.

Interpretation:

The prevalence of SCD varies significantly across assessment tools and geographic locations, particularly in rural areas and among older adults. Identifying influencing factors is crucial for effective prevention strategies, which should be informed by these findings.

Limitations:

• Predominant use of self-reported tools may introduce bias.
• Reliance on cross-sectional designs limits causal inferences.
• Geographic concentration of studies may limit generalizability to broader populations.

Conclusion:

Future research should integrate objective methods, prioritize longitudinal designs, investigate policy influences, and include diverse populations for culturally tailored prevention, particularly addressing the identified gap in policy environment research.