In one population survey of 7217 adults in the
Mini-Finland study [65], fibromyalgia was substantially
more common among agricultural workers (1.48%) than
among industrial workers (0.46%), service workers
(0.77%) or white-collar professionals (none of 1596
subjects). The survey also reported a stronger association
between fibromyalgia and OA (e.g. OR = 11.4,
95% CI = 6.1–21.3 for knee OA) than that explained
by the relationship of OA with agricultural work.
However, these findings have not been tested so far in
other studies and are currently unexplained