A population-based study of survival and discharge status for survivors after head injury

Creation of a basis for the planning of rehabilitation after head injury in Denmark.

Patients with cranial fractures or traumatic cerebral lesions occurring in Denmark in 1979-93 were identified by computerized searches in the national hospital register. Kaplan-Meier survival functions were calculated for these two categories. Hospital records for a random sample of 389 survivors in 1997 after cranial fracture, acute brain lesion or chronical subdural haematoma, which occurred in 1982, 1987 and 1992 in patients aged 15 years or more at injury, were reviewed. Survivors were characterized by age, gender, place and severity of injury, as well as neurophysical, speech and mental deficits at discharge from hospital.

Acute/subacute mortality of hospitalized patients was 27% for cerebral lesions and 4% after cranial fracture. As attrition by death outweighed the decreasing incidence with time, the point prevalence of survivors in 1997 after brain lesions occurring in 1982, 1987 or 1992 was nearly the same, averaging 8.4 per 100 000 of the population above age 14. Half of them were severe, as defined by initial Glasgow Coma Score < 9 for more than 6 h. There was no tendency with time of injury with regard to percentage occurrence of neurophysical, speech or mental deficits at discharge. The calculated number of candidates for rehabilitation of personal activities of daily life briefly after injury was 9.8 per 100 000 with cerebral lesion and 1.2 per 100 000 with cranial fracture. The severest 1.5 per 100 000 per year were candidates for early intensive centralized rehabilitation in special centres. Five years after injury, < 0.13 per 100 000 population survived in the vegetative state.

In this population-based study, survival after cranial fracture and cerebral lesion was described quantitatively through Kaplan-Meier survival distributions. Besides, patterns of severity, neurophysical and mental sequelae among survivors 5, 10 and 15 years post-injury were described. It was shown by examples how the study has been useful already for the planning of rehabilitation according to a national strategy from 1997 in Denmark. Besides, the results may serve as a reference for comparison with future studies.