Interaction between physical and psychosocial risk factors on the presence of neck/shoulder symptoms and its consequences

This study aimed to quantify the interaction between physical and psychosocial factors on the presence of neck/shoulder symptoms (NSS) and its consequences (reduced activities and absenteeism) among 1294 coal mining workers in Indonesia. A self-administered questionnaire was used to obtain information on current workplace exposure and NSS and its consequences. Participants were grouped into one of four combination exposure groups: low physical and low psychosocial (as the reference group); low physical and high psychosocial; high physical and low psychosocial, and high physical and high psychosocial (HPhyHPsy). The attributable proportion (AP) due to interaction between both factors was examined. Individuals in the HPhyHPsy group were most likely to report NSS [odds ratio (OR) 4.83, 95% confidence interval (CI) 2.43-9.58], reduced activities (OR 3.90, 95% CI 2.36-6.43), and absenteeism (OR 3.91, 95% CI 2.11-7.25). This study has shown an interaction between physical and psychosocial factors that increases the OR of NSS (AP 0.49, 95% CI 0.08-0.89).