Decline in Work Ability over Time and Its Association with Physical Performance Among Senior Workers: A Prospective...

Work ability (WA) decreases with age. This cohort study investigated changes in WA over time among senior workers and explored associations between WA and objectively measured physical performance.

A questionnaire regarding WA (0-100 points), work status and general health was sent out to individuals aged 50-65 years (n = 23,463) with a 6.5-year follow-up. A subgroup participated in a clinical substudy testing physical performance.

A total of 13,404 participants responded to the baseline questionnaire (56%) and 8474 (63%) responded at follow-up. Overall, WA decreased by -8.3 points over time (95% CI: -8.9 to -7.7). The decline was similar between genders and among senior workers with high or low physical work demands. The steepest decline in WA was among those aged 56-59 years at baseline (-10.3 points, 95% CI: -11.5 to -9.1). Clinical examination showed that WA was positively associated with higher isokinetic muscle strength, handgrip strength and functional capacity after adjusting for confounders (all p < 0.05).

Work ability decreased over time among all senior workers. Clinical subgroup analyses revealed positive associations between physical performance and WA. Future longitudinal studies are needed to determine whether improving physical performance can reduce age-related decline in work ability.