A Regression Discontinuity Model to Evaluate the Effect of Retirement on Phenotypic Aging: Results From a Large Cohort in China

OBJECTIVES: The primary objective of this study is to utilize a regression discontinuity model to rigorously evaluate the impact of retirement on phenotypic aging within a large cohort of Chinese adults using data from a large-scale physical examination in China. By leveraging the discontinuity from retirement age policies in China, we will identify the causal effects of retirement on biological aging markers and examine variations across different subgroups like genders. The findings will inform public health policies and retirement planning to promote healthy aging.

METHODS: A regression discontinuity design was conducted on a sample of 12,876 individuals. Unlike self-assessed health, phenotypic age provides a comprehensive, objective evaluation of health and is calculated from nine biological indicators along with chronological age. These indicators include Albumin, Creatinine, Glucose, C-reactive protein, Lymphocyte percent, Mean cell volume, Red cell distribution width, Alkaline phosphatase, and White blood cell count. Statistical comparisons were made using the regression discontinuity design with retirement age thresholds set at 60 years for men and 55 years for women.

RESULTS: Retirement had differential effects on phenotypic age by gender. For men, retirement was associated with an increase in phenotypic age, indicating worsening health post-retirement. Conversely, women showed a decrease in phenotypic age after retirement, suggesting improved health. These trends were visualized in graphical representations of phenotypic age changes around the retirement thresholds for both genders.

CONCLUSIONS: This study revealed gender-specific effects of retirement on phenotypic age. These findings were clearly depicted through graphical representations showing phenotypic age changes around retirement thresholds for both genders. These insights contribute to a broader understanding of how retirement influences health and aging, highlighting the need for tailored public health policies and retirement planning strategies that consider gender differences.