Do psychological factors predict outcome in both low-back pain and shoulder pain?

Psychological factors are assumed to predict persistent or recurrent musculoskeletal pain. The influence of psychological factors in patients with low-back pain (LBP) or shoulder pain was explored to study whether there is similarity regarding the factors that predict persisting pain and disability. Patients presenting in primary care with a new episode of shoulder pain or non-specific (sub)acute low back pain (LBP) were enrolled in a prospective study. In both patient groups, pain catastrophising, distress, somatisation and fear-avoidance beliefs were measured at baseline. Primary outcome measures at 3 months were (1) persistent symptoms, and (2) or=3 months) were higher scores on catastrophising significantly associated with persistent symptoms (p = 0.04). In patients with LBP, psychological factors were more strongly associated with poor outcome, although most associations were not significant. Psychological factors, with the exception of fear-avoidance beliefs, are more strongly associated with persistent pain and disability in patients with LBP than in those with shoulder pain. This seems to indicate that in a primary care population the influence of psychological factors on outcome may vary across patients with different types of pai