Does radiating spinal pain determine future work disability? A retrospective cohort study of 22,952 Danish twins

STUDY DESIGN.: Population-based, retrospective cohort. OBJECTIVE.: To determine whether radiating spinal pain from the low back, mid back, and neck is associated with future use of health-related benefits and their duration as compared with those with nonradiating spinal pain. SUMMARY OF BACKGROUND DATA.: Studies on the socioeconomic consequences of radiating pain have primarily focused on the low back and to a lesser extent on the neck and mid back. In addition, few studies report on the incidence of health-related benefit use after any radiating spinal pain. METHODS.: A cohort of 22,952 subjects was formed from the 2002 survey of the Danish Twin Registry. The survey contained information on spinal pain and important confounding factors. Work disability for an 8-year period was determined through data linkage with the Danish Register-Based Evaluation of Marginalization (DREAM) register of government transfer payments. We determined the incidence rate ratio for receipt of sickness benefit and the mean duration of the first and total sickness benefit periods by radiating and nonradiating spinal pain. Relative risks for the occurrence and number of sickness benefit episodes were calculated by radiating spinal pain status. RESULTS.: The incidence of sickness benefit was greater for those with radiating spinal pain (89.6 per 1000 person-years [95% confidence interval: 86.0, 93.2]) than those with nonradiating spinal pain (60.4 per 1000 person-years [95% confidence interval: 57.7, 63.1]). However, the duration of time off work, conditional on 1 day or more off work, was the same between those with and without radiating spinal pain. CONCLUSION.: Radiating spinal pain is an important risk factor for future sickness benefit. Radiating spinal pain was not associated with the duration of sickness benefit. These findings were independent of the effects of pain duration at baseline. The results highlight the need for interventions to prevent the onset of work disability, especially for those with radiating pain