RESEARCH ARTICLE Exploring How Pain Leads to Productivity Loss in Primary Care Consulters for Osteoarthritis: A Prospective Cohort Study

Objective Osteoarthritis pain has become a leading cause of decreased productivity and work disabili-ty in older workers, a major concern in primary care. How osteoarthritis pain leads to de-creased productivity at work is unclear; the aim of this study was to elucidate causal mechanisms and thus identify potential opportunities for intervention. Methods Population-based prospective cohort study of primary care consulters with osteoarthritis. Path analysis was used to test proposed mechanisms by examining the association be-tween pain at baseline, and onset of work productivity loss at three years for mediation by physical limitation, depression, poor sleep and poor coping mechanisms. Results High pain intensity was associated with onset of work productivity loss (Adjusted Odds Ratio 2.5; 95%CI 1.3, 4.8). About half of the effect of pain on work productivity was a direct effect, and half was mediated by the impact of pain on physical function. Depression, poo