Among residents of San Diego County, Califomia the incidence and external causes of serious brain injury were related to the median family income of the census tract of residency. Low income tracts had high incidence rates-a finding not changed by adjustment for age and race/ethnicity. For those injured, the type of emergency transport, time from injury to treatment, and outcome of treatment were not related to the median income of the census tract of residency. (Am J Public

Survival time after injury (the time from injury to death) imposes an important constraint on the timing of the delivery of postinjury medical care. From a population-based study of brain-injured people, the survival times in 542 cases with fatal outcomes were studied. Prehospital deaths as well as hospital deaths were included. Survival times were considerably shorter for 95 people with untreatable injuries (Abbreviated Injury Scale level 6) than for the remaining 447 whose injuries were potentially treatable. For the former group, the median survival time was 10 minutes; for the latter, it was 2 hours. For those with potentially treatable injuries, the median time from injury to receiving medical assistance was approximately 30 minutes and 82% received medical assistance within 1 hour of injury. Short survival time was associated with prehospital death, young age, high Injury Severity Score, and having a nonbrain injury as the most severe injury. For patients who arrived alive at a hospital, intracranial surgery was associated with increased survival time.