Until now, the effect of pain intensity on the association between widespread pain and sickness absence had not been studied although, both musculoskeletal pain-intensity with respect to a specific location (like lower back or shoulder) and pain in multiple body regions have been shown to be related with impaired function and sickness absence. Also, it is unknown whether care-seeking in general practice because of musculoskeletal disorders has a positive or negative effect on future absenteeism.

The aim of the study mentioned here was to investigate the influence of pain intensity on the association between number of musculoskeletal pain sites and sickness absence, and to assess the effect on absenteeism from care-seeking in general because of musculoskeletal disorders.

In February 2008, a total of 3745 Danish adults registered with eight General Practitioners (GPs) in one primary medical center delineated location and intensity of experienced musculoskeletal pain in seven different body regions. From 4 years, the outcome was timespan of sickness absence based on register data split into long-term (>52 weeks during follow-up) and sickness absence of shorter timespan (12–52 weeks during follow-up). The data on pain-intensity were investigated at three different cut-off stages for each body region: i) > 1 (any pain), ii) > 2 (bothersome pain), iii) > 3 (very bothersome pain). The analyses were divided and distinguished between people without GP contact and people with GP contact because of musculoskeletal disorders.

Musculoskeletal pain in more than two body regions was strongly analogous to long-term sickness absence in an exposure-response pattern. Different cut-off levels of pain intensity and adjustment for age, sex, educational level and work environmental factors did not have any impact on the results. Although the association was weaker, similar findings were noticed for sickness absence of shorter duration.

It was thus concluded that the intensity of pain and care-seeking because of musculoskeletal disorders did not seem to influence the association between the number of pain locations and later sickness absence. The number of musculoskeletal pain locations seems to be a powerful risk factor for later sickness absence.