O-406 Longitudinal Study of Knee Pain Amongst Workers in the Cultural and Psychosocial Influences on Disability (Cupid) Study

Background Knee pain (KP) is common often leading to disability and early workforce exit. In a large group of workers, we examined the prevalence of KP longitudinally, its relationship with pain elsewhere, and personal and occupational effects on pain at follow-up. Methods Data from the CUPID study, comprising office workers, nurses and manual workers (ages 20-59) from 18 countries, collected baseline information on KP, other pain sites, occupational characteristics, and general health. Follow-up information about KP was obtained a year later. Descriptive statistics were used to describe KP prevalence, characteristics and persistence. Logistic regression examined baseline factors in relation to follow-up KP, and disabling KP. Results Among 9161 workers, 28% reported KP in the past year and 21% KP in the past month. 79% of workers with KP reported disability. The prevalence increased with age and was higher among women. Only 8% of workers with KP had single-site pain. Prevalence rates varied widely even amongst workers doing broadly similar work. Psychosocial and physically-demanding work factors predicted KP at follow-up, as did poorer mental health and somatisation. Yet, the highest effect size was that of number of painful sites at baseline (IRR:2.06, 95%CI:1.78-2.39). Discussion In our cohort, KP was prevalent, even at younger ages and frequently persistent and disabling. Pain at other sites had the strongest predictive effect, surpassing other known impacts of KP. Conclusion The results emphasize a biopsychosocial approach for KP management, similar to that suggested for low back and non-specific arm pain. Solely focusing on knee structural damage may not be universally effective.