Factors affecting subjective cognitive decline in older adults based on the health ecological model: a scoping review

Objective To systematically review and synthesize the factors influencing subjective cognitive decline (SCD) in older adults based on the Health Ecological Model (HEM), and to provide direction for future research. Methods Relevant literature on factors influencing SCD in older adults was retrieved from five databases (CNKI, Wanfang, VIP, PubMed, and Web of Science) from database inception to October 18, 2025. Results A total of 33 articles were included, comprising 21 Chinese and 12 English articles, with sample sizes ranging from 212 to 74,472 participants. The influencing factors were diverse and complex. According to the HEM, these factors were categorized into four dimensions: personal characteristics, behavioral characteristics, interpersonal networks, and living and working conditions. Notably, none of the 33 studies addressed the fifth dimension—the policy environment—highlighting a significant research gap. Conclusion The reported prevalence of SCD varies considerably across assessment tools and geographic locations, particularly in rural areas and among older adults. Four dimensions of influencing factors were identified: personal characteristics, behavioral characteristics, interpersonal networks, and living and working conditions. None of the 33 included studies addressed the policy environment dimension, highlighting a significant research gap. Limitations include the predominant use of self-reported tools, reliance on cross-sectional designs, and geographic concentration, limiting generalizability. Future research should integrate objective methods, prioritize longitudinal designs, investigate policy influences, and include diverse populations for culturally tailored prevention.