Original article

Scand J Work Environ Health 2011;37(6):455-463    pdf


Work strain in midlife and 28-year work ability trajectories

by von Bonsdorff ME, Kokko K, Seitsamo J, von Bonsdorff MB, Nygård C-H, Ilmarinen J, Rantanen T

Objectives We investigated the 28-year development trajectories of work ability among initially middle-aged male and female municipal employees and the association of perceived mental and physical work strain in midlife by work ability trajectory groups.

Methods The baseline data of the Finnish longitudinal study of municipal employees (FLAME) were collected in 1981 (N=6257) with follow-ups in 1985, 1992, 1997, and 2009. Work ability was assessed in all the waves as present perceived work ability relative to lifetime best. Altogether, N=2690 had work ability data in 1981 and 2009, and at least for one wave in between these years, and were included in group-based semi-parametric mixture modeling trajectory analyses. Baseline differences in mental and physical work strain according to the work ability trajectories were assessed with MANCOVA (multivariate analysis of covariance).

Results A five-group work ability trajectory model was identified for men and a four-group model for women. For the majority, a linear decline from excellent to moderate or moderate to poor work ability was observed while non-linear trajectories with sudden collapse and, in some cases, modest subsequent recovery of work ability were also observed. Individuals who maintained their work ability on an excellent-to-moderate level throughout the follow-up more often reported low mental and physical work strain in midlife.

Conclusions A substantial proportion of individuals seem to maintain their work ability on a moderate level from midlife to old age. Work strain may have far-reaching negative effects on individuals’ work ability from midlife to old age, warranting vigilance in maintaining and promoting work ability throughout the lifespan.