Life expectancy after spinal cord injury: a 50-year study

Study design: Cohort of incident cases from 1955 to 2006. Objectives: To analyse acute and long-term mortality, estimate life expectancy and identify survival patterns of individuals experiencing traumatic spinal cord injury (SCI). Setting: Specialised SCI unit in Australia. Methods: Data for patients with traumatic SCI admitted to a spinal unit in Sydney, Australia between January 1955 and June 2006 were collated and deaths confirmed. Cumulative survival probability was estimated using life-table techniques and mortality rates were calculated from the number of deaths and aggregate years of exposure. Standardised mortality ratios (SMRs) were estimated from the ratio of observed to expected number of deaths. Life expectancy was then estimated using adjusted attained age-specific mortality rates. Results: From 2014 persons, 88 persons with tetraplegia (8.2%) and 38 persons with paraplegia (4.1%) died within 12 months of injury, most often with complete C1-4 tetraplegia. Among first-year survivors, overall 40-year survival rates were 47 and 62% for persons with tetraplegia and paraplegia, respectively. The most significant increases in mortality were seen in those with tetraplegia and American Spinal Injury Association Impairment Scale (AIS) grades A-C lesions, with SMRs between 5.4 and 9.0 for people <= 50 years, reducing with advancing attained age. Estimated life expectancies from 25 to 65 years ranged between 69-64%, 74-65%, 88-91% and 97-96% for C1-4 AIS A-C, C5-8 A-C, T1-S5 A-C and all AIS D lesions, respectively. Conclusion: Survival related strongly to extent of neurological impairment. Future research should focus on identifying contextual factors, personal or environmental, that may contribute to the reduced life expectancy after SCI. Spinal Cord (2012) 50, 803-811; doi:10.1038/sc.2012.55; published online 15 May 2012