Biomedical and psychosocial factors associated with disability after peripheral nerve injury.

BACKGROUND The purpose of this study was to evaluate the biomedical and psychosocial factors associated with disability at a minimum of six months following upper-extremity nerve injury. METHODS This cross-sectional study included patients who were assessed between six months and fifteen years following an upper-extremity nerve injury. Assessment measures included patient self-report questionnaires (the Disabilities of the Arm, Shoulder and Hand Questionnaire [DASH]; pain questionnaires; and general health and mental health questionnaires). DASH scores were compared by using unpaired t tests (sex, Workers' Compensation/litigation, affected limb, marital status, education, and geographic location), analysis of variance (nerve injured, work status, and income), or correlations (age and time since injury). Multivariable linear regression analysis was used to evaluate the predictors of the DASH scores. RESULTS The sample included 158 patients with a mean age (and standard deviation) of 41 ± 16 years. The median time from injury was fourteen months (range, six to 167 months). The DASH scores were significantly higher for patients receiving Workers' Compensation or involved in litigation (p = 0.02), had a brachial plexus injury (p = 0.001), or were unemployed (p < 0.001). There was a significant positive correlation between the DASH scores and pain intensity (r = 0.51, p < 0.001). In the multivariable regression analysis of the predictors of the DASH scores, the following predictors explained 52.7% of the variance in the final model: pain intensity (Beta = 0.230, p = 0.006), brachial plexus injury (Beta = -0.220, p = 0.000), time since injury (Beta = -0.198, p = 0.002), pain catastrophizing score (Beta = 0.192, p = 0.025), age (Beta = 0.187, p = 0.002), work status (Beta = 0.179, p = 0.008), cold sensitivity (Beta = 0.171, p = 0.015), depression score (Beta = 0.133, p = 0.066), Workers' Compensation/litigation (Beta = 0.116, p = 0.049), and female sex (Beta = -0.104, p = 0.090). CONCLUSIONS Patients with a peripheral nerve injury report substantial disability, pain, and cold sensitivity. Disability as measured with the DASH was predicted by brachial plexus injury, older age, pain intensity, work status, time since injury, cold sensitivity, and pain catastrophizing.