Multi-trajectory of musculoskeletal and mental disorders: a multi-cohort study

Abstract Background Musculoskeletal and mental disorders often co-occur with and contribute significantly to work disability and reduced quality of life in aging populations. These conditions may follow distinct or overlapping progression patterns across the life course, particularly from midlife to old age. We studied the multi-trajectory of back pain and mental disorders from midlife to old age and examined the role of work-related physical and psychosocial factors in four cohort studies from Europe (Finland, France, and the UK) and the US. Methods Data from four independent prospective cohort studies: ELSA, FLAME, GAZEL, and HRS were used. About 40,000 participants aged 36-66 years (mean age 50 years) at baseline, who had information on back pain (yes/no) and reported common mental disorders from at least three points of the follow-up in each cohort, were studied. Potential joint development of back pain and mental disorders was examined with multi-trajectory models in each cohort separately. Results Three trajectory models were identified as the best fitted solution in each cohort with majority (50-70%, varies between cohorts) having both increased back pain and increasing mental disorders over time, about 5-20% had increased back pain but decreased in mental disorders and about 20-35% had changing back pain and increasing mental disorders. The majority had increased back pain and mental disorders simultaneously, which increased with age. Conclusions This multi-cohort study suggests the co-occurrence of back pain and common mental disorders among midlife employees, and the increasing levels of both symptoms were found with increasing age. The finding suggests that in clinical practice, these symptoms should be looked at together in their early phase. Key messages • Musculoskeletal pain and common mental disorders among midlife employees co-occurs. • Increasing levels of both symptoms were found by increasing age and this trend was similar in all studied cohorts.