Disability pensions in relation to traumatic brain injury: a population study

From a Danish national register of hospitalizations, all patients were identified who had a discharge diagnosis of traumatic brain injury between the years 1979-1993 inclusive, at ages 18-66 years inclusive. These were classified as having suffered either a concussion (n = 74,398), a cranial fracture (n = 4,452) or a cerebral contusion (n = 8,141). Patients in each of these groups were then checked in annual registers of disability pension awards between 1979-1995. Disability pensions had been awarded to 16% of the concussion group, 18% of the fracture group, and 33% of the contusion group. Date of application, grounds for the application, and the pension level awarded were noted. Analysis of the date of application for the disability pension revealed that in all groups a high proportion of the pension applications had been made prior to the injury. Among the concussion group, the pension award appeared to be independent of the injury itself. Rather, being awarded a disability pension appeared to be related to conditions which themselves are risk factors for a traumatic brain injury, e.g. chronic skeletomuscular disease and psychiatric disorders including alcoholism. Comparison with population statistics revealed that the relative risk of being assigned a low or intermediate disability pension is markedly elevated among the concussion group, especially at younger ages and among males. For the fracture and contusion groups, a clear post-injury elevation in rate was detectable, especially for highest level pensions.