Retirement age and disability status as pathways to later‐life cognitive impairment: Evidence from the Norwegian HUNT Study linked with Norwegian population registers

Abstract

Background Research shows that retirement age is associated with later‐life cognition but has not sufficiently distinguished between retirement pathways. We examined how retirement age was associated with later‐life dementia and mild cognitive impairment (MCI) for people who retired via the disability pathway (received a disability pension prior to old‐age pension eligibility) and those who retired via the standard pathway. Methods The study sample comprised 7210 participants from the Norwegian Trøndelag Health Study (HUNT4 70+, 2017–2019) who had worked for at least one year in 1967–2019, worked until age 55+, and retired before HUNT4. Dementia and MCI were clinically assessed in HUNT4 70+ when participants were aged 69–85 years. Historical data on participants' retirement age and pathway were retrieved from population registers. We used multinomial regression to assess the dementia/MCI risk for women and men retiring via the disability pathway, or early (<67 years), on‐time (age 67, old‐age pension eligibility) or late (age 68+) via the standard pathway. Results In our study sample, 9.5% had dementia, 35.3% had MCI, and 28.1% retired via the disability pathway. The disability retirement group had an elevated risk of dementia compared to the on‐time standard retirement group (relative risk ratio [RRR]: 1.64, 95% CI 1.14–2.37 for women, 1.70, 95% CI 1.17–2.48 for men). MCI risk was lower among men who retired late versus on‐time (RRR, 0.76, 95% CI 0.61–0.95). Conclusion Disability retirees should be monitored more closely, and preventive policies should be considered to minimize the dementia risk observed among this group of retirees.