Spinal Cord Injury
The research literature shows clearly that life expectancy in SCI is significantly reduced from normal. The magnitude of the reduction depends on level and grade. As would be expected, life expectancy is less if the injury is complete and/or the neurological level is higher.
For some examples, see Table 4 from Strauss et al. 2007,5 which is reproduced below. It applies to a 25 year-old male. As may be seen, in the most severe case (complete injury at levels C1 - C3), the life expectancy is 50% of normal. For grade D injuries ("minimal neurological deficit"), the estimate is 88% of normal. For females, or for persons older than 25, the percentage of normal life expectancy is similar, to a rough approximation, though the percentage tends to be somewhat smaller at older ages.
Ventilator-dependence. The research data shows that the great majority of persons who are permanently ventilator-dependent after SCI have complete injuries at the high or mid-cervical levels. As would be expected, such persons are subject to higher rates of morbidity and mortality, and life expectancy is therefore lower than for persons with injuries of the same grade and level who are not ventilator-dependent. The most recent research on life expectancy of ventilator-dependent persons4 indicates lower life expectancies than had been reported earlier.7,13
Persons whose SCI occurred in childhood have lower life expectancies than those injured in adulthood, other factors being equal.3
Secular trends in life expectancy after SCI. It seems to be widely believed that life expectancy after SCI has improved dramatically in recent decades. A careful reading of the research literature5,7,9 shows, however, that the pattern is more complex than this. There has been a major improvement in survival during the critical first few years after the injury, mortality rates having fallen by some 50% in recent decades. For the subsequent period, however, there has been little if any improvements in survival.
Smoking and SCI. The research literature indicates that smoking is especially deleterious for persons with SCI.
The same appears to be true of persons with SCI who are morbidly obese.
It has been suggested that economic factors play a major role in life expectancy of persons with SCI (Krause et al.14). More recent work,1 however, indicates that this is not the case, except that persons with SCI in the most unfavorable economic category fare significantly worse than the others.
The studies referenced above are available on the articles page.