Natural history and predictors of long-term pain and function among workers with hand symptoms.

OBJECTIVE To evaluate predictors of hand symptoms and functional impairment after 3 years of follow-up among workers with different types of hand symptoms including carpal tunnel syndrome (CTS). Functional status and job limitations were also analyzed as key secondary objectives. DESIGN Cohort design of 3 years duration. SETTING Working population-based study. PARTICIPANTS Newly employed workers without a preexisting diagnosis of CTS (N=1107). Subjects were categorized into 4 groups at baseline examination: no hand symptoms, any hand symptoms but not CTS (recurring symptoms in hands, wrist, or fingers without neuropathic symptoms), any hand symptoms of CTS (neuropathic symptoms in the fingers and normal nerve conduction study), or confirmed CTS (CTS symptoms and abnormal nerve conduction study). Among workers with hand pain at baseline, subject and job characteristics were assessed as prognostic factors for outcomes, using bivariate and multivariate regression models. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURE The primary outcome assessed by questionnaire at 3 years was "severe hand pain" in the past 30 days. RESULTS At baseline, 155 workers (17.5% of 888 followed workers) reported hand symptoms, of which 21 had confirmed CTS. Presence of hand pain at baseline was a strong predictor of future hand pain and job impairment. Subjects with confirmed CTS at baseline were more likely than workers with other hand pain to report severe hand pain (adjusted prevalence ratios 1.98 [95% confidence interval 1.11-3.52]) and functional status impairment (adjusted prevalence ratios 3.37 [95% confidence interval 1.01-11.29]). Among subjects meeting our case definition for CTS at baseline, only 4 (19.1%) reported seeing a physician in the 3-year period. CONCLUSIONS Hand symptoms persisted among many workers after 3-year follow-up, especially among those with CTS, yet few symptomatic workers had seen a physician.