Factors associated with musculoskeletal pain in the past 12 months amongst female miners in a South African goldmine.

Because exposure and pain were measured at the same time, the study cannot show which came first or that a factor caused pain. Only 225 of the 553 invited women were analysed, and the paper reports 40.69% participation, so responders may differ from non-responders. Pain and work factors were self-reported, and voluntary participation could have influenced what women said. The study included only black South African female mineworkers at one gold mine, excluding 36 women not directly in mining activities and all non-black female employees. The question about pain lasting more than 3 months was poorly answered, so chronic pain could not be assessed. The analysis combined moderate and high pain intensity to make the model converge, so differences between those pain levels cannot be seen. Some crude associations did not remain significant after adjustment, including repetitive movement, physical load, work control, organisational culture and chronic illness. Only current employees were included, so women who left because of illness were missed, which could bias findings toward the null.

Do not conclude that reducing repetitive movement or physical load will prevent pain in female miners. The study measured exposure and pain at the same time, and those associations were not significant after adjustment.