A Systematic Review Toward a Comprehensive Framework for Measuring Non-chronological Age

As populations age globally, there is a need to refine the understanding of aging beyond simply chronological age. Therefore, this study used the PRISMA framework to synthesize literature on alternative aging metrics beyond chronological age. We analyzed articles from 6 databases (SCOPUS, PsychINFO, Web of Science, CINAHL, Engineering Village, and PubMed) and selected 18 articles that explored factors that lead to older adults’ individual differences. Findings indicated the necessity of a consistent terminology that better describes one’s cognitive and physical functioning, such as “non-chronological age.” Also, the review found that daily cognitive, physical, and social activities may result in different non-chronological ages. A comprehensive tool to measure non-chronological age and thereby provide a more accurate representation of aging that incorporates these critical factors is needed. The findings may contribute to the development of theories in non-chronological age.