Expectation of life and unexpected death in open spina bifida: a 40-year complete, non-selective, longitudinal cohort study.

AIM

The aim of our study was to investigate survival and causes of death in a complete cohort of open spina bifida at the mean age of 40 years.

METHOD

We conducted a community-based, prospective study of 117 consecutive infants (50 males, 67 females) with open spina bifida whose backs were closed non-selectively within 48 hours of birth between 1963 and 1971 at Addenbrooke's Hospital, Cambridge, UK. Of those who survived to age 1 year, 89% (82 out of 92) had a cerebrospinal fluid shunt. In 2007, all survivors were surveyed by postal questionnaire backed up by telephone interview. Details of deaths were obtained from the Office for National Statistics, medical records, and autopsy reports, and Kaplan-Meier survival curves were constructed.

RESULTS

One in three of the cohort (40/117) died before the age of 5 years. A further 26% (31/117) died during the next 35 years, over 10 times the national average. Half the deaths (16/31) after the age of 5 were sudden and unexpected. All occurred in the community and were followed by a coroner's autopsy. The most frequent causes of these unexpected deaths were epilepsy, pulmonary embolus, acute hydrocephalus, and acute renal sepsis. The prognosis for survival was strikingly poor in those with the most extensive neurological deficit. Only 17% (7/42) of those born with a high sensory level (above T11) survived to the mean age of 40 years, compared with 61% (23/38) of those with a low sensory level (below L3; p=0.001).

INTERPRETATION

Doctors and care planners need to be aware that, contrary to previous suggestions, there is continuing high mortality throughout adult life in individuals with open spina bifida, and many deaths are unexpected.