A case-control study of risk factors for arm pain presenting to primary care services

Objectives To investigate the association of occupational activities, mental health and comorbidity with care seeking for arm pain, and to test the hypothesis that specific disorders arise from physical risk factors and non-specific pain from psychological ones. Methods Patients with a new episode of arm pain and matched controls were recruited from eight general practices. A questionnaire about risk factors was completed and cases were classified using a validated examination schedule. Questions were asked about occupational activities and psychosocial stressors. Mental health was assessed using the Hospital Anxiety Depression Scale, elements of the Brief Symptom Inventory (somatizing tendency) and the Whiteley Index (health anxiety); comorbidity from chronic fatigue syndrome (CFS) and chronic widespread pain (CWP) was ascertained using standard definitions. Associations were explored using logistic regression and summarized as odds ratios (ORs) with 95% confidence intervals (95% CIs). Results Altogether, 132 cases and 127 controls were studied. Consulting with arm pain was strongly associated with all of the mental health variables and with CFS and CWP, irrespective of the site of arm pain or diagnosis. The OR in those with > 3 versus < 3 distressing somatic symptoms was 3.9 ( 95% CI 1.7-9.0). There were several significant associations with physical activity, but none with occupational psychosocial stressors. Repeated wrist/finger movements and carrying weights were more strongly associated with specific diagnoses than with non-specific pain. Conclusions Somatizing tendency, health anxiety, low mood, CFS and CWP are more common in arm pain consulters. Certain mechanical activities are also overrepresented, particularly in those with specific pathology.