LAS VEGAS – A higher-than-expected proportion of trauma-related deaths occur in the months and years after hospital discharge, according to findings from a prospective cohort study.
In 908 trauma patients followed for up to 9.8 years (median, 1.7 years), overall mortality was 27%, and in 509 patients followed for at least 2 years, overall mortality was 38%. Mortality was highest among those who were severely injured (43% at 5 years), Dr. Rachael A. Callcut reported at the annual meeting of the American Association for the Surgery of Trauma.
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The median Injury Severity Scale score was 18, but for all ISS groups, survival was significantly worse than predicted actuarial survival for that group – even after exclusion of deaths that occurred within 30 days, she said.
For example, at 5 years, predicted actuarial survival was greater than 95%, but actual survival was about 90% for those with ISS less than 15, about 85% for those with ISS of 15-24, and about 57% for those with ISS greater than 24. This dose-response–like relationship between injury severity and mortality demonstrates that the deaths are not just occurring in “patients who are old and would have died from a heart attack anyway” she explained.
The 30-day mortality in the cohort was 22%, and in-hospital mortality was 22.9%, as eight patients who died after the first 30 days did so in the hospital. Forty-five of the 245 deaths (18%) occurred after 30 days, and 36 of those (80%) occurred after hospital discharge, meaning the out-of-hospital mortality rate was 5.3% overall, and 10% for the most severely injured (hazard ratio, 2.7 for the most severe vs. the least severe injuries).
“I personally found this quite striking given that when a patient leaves the hospital, we feel, to some degree, that we won – only to find out that at least 5% of these patients will go on to subsequently die,” said Dr. Callcut of the University of California San Francisco, adding that “if you look at it slightly differently, which is even more concerning, 37 of the out-of-hospital deaths of the total of 245 deaths, mean that out-of-hospital deaths account for 15% of the total mortality following trauma.”
Further, of the deaths that occurred after 30 days, 53% occurred between 31 days and 1 year after trauma, and trauma was the leading cause of postdischarge death, accounting for 41% of the late deaths, she said.
The patients included in this analysis were all highest level trauma activation patients enrolled in the ongoing study between 2005 and 2012. Comprehensive prospective data were collected, and patients were followed throughout their hospitalization and after discharge. Institutional medical records or death certificates were used to determine timing and cause of death, and survival status was determined based on the last date of care in the institution or by query of the National Death Index for 2013.
These findings provide a rare glimpse of trauma-related outcomes among patients discharged from the hospital. Most prior studies focused on 30-day outcomes, with a few extended out to 90 days, but very few studies have looked at long-term outcomes, Dr. Callcut noted.
“You could say that despite having survived to leave the hospital alive, long-term survival is actually worse than predicted actuarial survival, and this suggests to us that successful hospital discharge does not mean success for your patient,” she concluded.
Dr. Callcut was supported in part by a National Institutes of Health award.