A prospective cohort study of arm pain in primary care and physiotherapy--prognostic determinants

To investigate outcome and prognostic determinants for arm pain presenting to primary care and physiotherapy services.

Patients with arm pain were recruited as they presented to primary care and physiotherapy services, and were followed for 12 months. At baseline, they were classified by diagnosis using a validated examination schedule. Depression, somatizing tendency, health anxiety, fear-avoidance beliefs and chronic pain outside the arm were ascertained using standard definitions. Three outcomes were considered: same-site pain during the final month of follow-up (continuing pain); pain present on most days of that month; and pain present without a break of 7 days over follow-up ('unremitting' pain). Associations were explored in multi-level logistic regression models and summarized as odds ratios (ORs) with 95% confidence intervals (95% CIs).

Altogether, 313 (83%) of 375 subjects completed follow-up, including 53% with 'continuing' and 24% with 'unremitting' pain. 'Continuing' pain was predicted most strongly by male sex (OR 1.9, 95% CI 1.2-3.2) (this association was restricted largely to the elbow), higher frequency of pain in the past month at baseline (OR 2.5, 95% CI 1.1-5.6), chronic pain at sites outside the arm (ORs 1.6-2.4 for different sites) and current smoking (OR 3.3, 95% CI 1.6-6.6). There were also indications that mental health and fear-avoidance beliefs influenced prognosis. Predictors for the other two adverse outcomes were similar.

Arm pain often persists in patients who consult medical services. Predictors of persistence include male sex (elbow only), frequency of pain at baseline, chronic pain at other sites and smoking.