The Impact of Education and Lifestyle Factors on Disability-Free Life Expectancy From Mid-Life to Older Age: A Multi-Cohort Study.

Objectives: Low education and unhealthy lifestyle factors such as obesity, smoking, and no exercise are modifiable risk factors for disability and premature mortality. We aimed to estimate the individual and joint impact of these factors on disability-free life expectancy (DFLE) and total life expectancy (TLE). Methods: Data (n = 22,304) were from two birth cohorts (1921-26 and 1946-51) of the Australian Longitudinal Study on Women's Health and linked National Death Index between 1996 and 2016. Discrete-time multi-state Markov models were used to assess the impact on DFLE and TLE. Results: Compared to the most favourable combination of education and lifestyle factors, the least favourable combination (low education, obesity, current/past smoker, and no exercise) was associated with a loss of 5.0 years TLE, 95% confidence interval (95%CI): 3.2-6.8 and 6.4 years DFLE (95%CI: 4.8-7.8) at age 70 in the 1921-26 cohort. Corresponding losses in the 1946-51 cohort almost doubled (TLE: 11.0 years and DFLE: 13.0 years). Conclusion: Individual or co-ocurrance of lifestyle risk factors were associated with a significant loss of DFLE, with a greater loss in low-educated women and those in the 1946-51 cohort.