Chronic upper limb pain: an exploration of the biopsychosocial model

To model pain intensity and consequent disability by independent physical, psychological, and social variables in a group of patients with chronic upper limb pain.

We studied a group of 73 hospital outpatients with either chronic work related diffuse upper limb pain or carpal tunnel syndrome. We assessed pain intensity, disability, and personality by self-rated questionnaires; and psychiatric morbidity by a standardized interview. We measured illness behavior by assessing coping strategies, illness beliefs, financial benefits, and movements of the most affected limb.

In both pain conditions, disability was positively correlated with present pain intensity, depression, helpless coping style, and receipt of state financial benefits; and was negatively correlated with age. This explained 43% of the variance and correctly classified 85% of all patients. Present pain intensity was positively correlated with both depression and the number of arm movements at night. This model explained 15% of the variance and correctly classified 75% of all patients. Inclusion of diagnostic group has no effect on these models.

The correlations between disability and pain intensity with both psychosocial and physical factors support the biopsychosocial model of disability in particular, and pain to a lesser extent, irrespective of the diagnosis.