Long-term survival of elderly trauma patients

OBJECTIVE

To evaluate the long-term survival and factors that influence survival among a cohort of elderly trauma patients compared with an uninjured cohort.

DESIGN

A retrospective cohort analysis.

DATA SOURCES

Health Care Finance Administration, Baltimore, Md, Medicare data.

SUBJECTS

A cohort of elderly patients (n = 9424) hospitalized for injury in 1987 was identified using Medicare hospital discharge abstract data. An uninjured comparison group (n = 37,787) was identified from Medicare eligibility files. For injured patients, an Injury Severity Score was generated from the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9CM) codes. For both cohorts, preexisting illness was assessed by ICD-9CM codes from Health Care Finance Administration outpatient and inpatient data files for 1986 and 1987.

MAIN OUTCOME MEASURES

Relative risk for mortality within 5 years subsequent to injury, adjusted for age, sex, and preexisting illness, using Cox proportional hazard regression.

RESULTS

The injured cohort had a significantly reduced 5-year survival when compared with the uninjured group (relative risk [RR] = 1.71; 95% confidence interval, 1.66-1.77). The lower survival persisted even among patients who survived at least 3 years after injury. Coexisting disease, age, and Injury Severity Score were strong predictors of survival.

CONCLUSIONS

The adverse effect of trauma on survival in elderly patients is not isolated to the immediate postinjury period, but lasts years after the trauma episode. Further study is required to identify the reasons for this persistent effect of trauma on subsequent survival.

Trauma recidivism in the elderly

BACKGROUND

The incidence of recurrent trauma in the elderly is unknown. This study evaluated the risk of readmission for injury among elderly trauma patients compared with an uninjured geriatric cohort. The effects of age, sex, race, preexisting illness, and ISS on trauma recidivism were determined.

METHODS

Population based retrospective cohort analysis of the elderly using administrative data from the Health Care Financing Administration was performed. The measured outcome was trauma admission within 5 years. The injured were identified using hospital discharge data and the Injury Severity Score generated by ICD-Map. The uninjured were identified from Medicare eligibility files. Comorbid illness was assessed using ICD-9CM codes from outpatient and inpatient data files.

RESULTS

The injured members of the cohort had increased risk of subsequent new trauma admission (p < 0.001). Increasing Injury Severity Score, age, and comorbid illness are associated with trauma recidivism.

CONCLUSION

Trauma in the elderly is recurrent. Further study is required to develop age and injury specific interventions to prevent recurrent injury.

Hospitalizations for injury in New Zealand: prior injury as a risk factor for assaultive injury

OBJECTIVES

This study sought to determine the degree to which injury hospitalization, especially for assaultive injury, is a risk for subsequent hospitalization due to assault.

METHODS

A New Zealand hospitalization database was used to perform a retrospective cohort study. Exposure was defined as an injury hospitalization, stratified into assaultive and nonassaultive mechanisms. Hospitalizations for an assault during a 12-month follow-up period were measured.

RESULTS

Individuals with a prior nonassaultive injury were 3.2 times more likely to be admitted for an assault than those with no injury admission (95% confidence interval [CI] = 2.7, 3.9). The relative risk associated with a prior assault was 39.5 (95% CI = 35.8, 43.5), and the subsequent admission rate did not vary significantly by sex, race, or marital or employment status. Among those readmitted for an assault, 70% were readmitted within 30 days of the initial hospitalization.

CONCLUSIONS

Prior injury is a risk for serious assault, and the risk is even greater if the injury is due to assault. Risk of readmission for assault is largely independent of demographic factors and greatest within 30 days of the initial assault.

Motorcycle helmet use and injury outcome and hospitalization costs from crashes in Washington State

OBJECTIVES

The incidence, type, severity, and costs of crash-related injuries requiring hospitalization or resulting in death were compared for helmeted and unhelmeted motorcyclists.

METHODS

This was a retrospective cohort study of injured motorcyclists in Washington State in 1989. Motorcycle crash data were linked to statewide hospitalization and death data.

RESULTS

The 2090 crashes included in this study resulted in 409 hospitalizations (20%) and 59 fatalities (28%). Although unhelmeted motorcyclists were only slightly more likely to be hospitalized overall, they were more severely injured, nearly three times more likely to have been head injured, and nearly four times more likely to have been severely or critically head injured than helmeted riders. Unhelmeted riders were also more likely to be readmitted to a hospital for follow-up treatment and to die from their injuries. The average hospital stay for unhelmeted motorcyclists was longer, and cost more per case; the cost of hospitalization for unhelmeted motorcyclists was 60% more overall ($3.5 vs $2.2 million).

CONCLUSIONS

Helmet use is strongly associated with reduced probability and severity of injury, reduced economic impact, and a reduction in motorcyclist deaths.

Children in car crashes: analysis of data for injury and use of restraints

OBJECTIVE

To determine the effect of car restraints on motor vehicle injury rates for children aged 0 to 14 years.

METHODS

A probability sample of all police-reported car crashes in the United States in 1990 and 1991 was analyzed for injury rates of passengers aged less than 15 years in relation to restraint usage, age, and seating position.

RESULTS

Optimal restraint usage (defined as car seats for children 0 to 4 years old and lap shoulder belts for children 5 to 14 years old) was 40%. The use of the car seat was 76% for infants (0 to 12 months old) and 41% for toddlers (1 to 4 year olds). The non use of a restraint was highest for 10 to 14 year olds (43%). The rate of involvement in car crashes for all children was 21.4 (per 1000/yr). The highest rate was the 14 year olds with 29.6 followed by 2 year olds with 26.5. Injury rates were 4.76 (per 1000/yr) for all children. The lowest rate was 2.91 for infants but increased to 4.78 for 3 year olds. The single strongest risk factor for injury was the non use of a restraint. (Adjusted odds ratio 2.7; 95% CI 2.4 to 3.0.) The risk factor for injury for the front seat was 1.5 (95% CI 1.4 to 1.7). Use of the car seat reduced injuries by 60% for 0 to 4 year olds, whereas the lap shoulder harness was only 38% effective for 5 to 14 year olds (P < or = .001) Injury rates of unrestrained 0 to 4 and 5 to 14 year olds were similar.

CONCLUSIONS

Greater involvement in car crashes and less use of car restraints explains the 64% higher rate of injury for 3 year olds than for infants. It is time to target the toddlers. Restraints designed for adults are not as effective for the school age child as car seats are for the preschool child. A better restraint for the school age child should be designed and evaluated. Meanwhile, increased usage of current restraints must be encouraged, as they substantially reduce injuries.

The effects of alcohol abuse on readmission for trauma

OBJECTIVE

To determine the effect of admission for trauma with concurrent acute alcohol intoxication or chronic alcohol abuse on the risk of subsequent recurrence of trauma.

DESIGN

Prospective cohort study.

SETTING

Level I regional trauma center.

PATIENTS

A total of 2578 patients 18 years or older admitted with blunt or penetrating trauma within 24 hours of injury and surviving to discharge. All patients had a blood alcohol concentration (BAC) test, a gamma-glutamyltransferase (GGT) test, and the short Michigan Alcohol Screening Test (SMAST) performed on admission.

MAIN OUTCOME MEASUREMENT

Readmission to the trauma center for new trauma. Average follow-up was 28 months (range, 16 to 40 months).

RESULTS

The overall rate of readmission for new injuries was 1.3 per 1000 patient-months of follow-up. Patients who were intoxicated on the initial admission (BAC > 22 mmol/L [100 mg/dL]) were 2.5-fold as likely to be readmitted than those not intoxicated (95% confidence limits, 1.6, 3.9). The relative risks for patients with positive SMAST scores and abnormal GGT values were 2.2 (95% confidence limits, 1.4, 3.5) and 3.5 (95% confidence limits, 2.2, 5.5), respectively. The increased risks remained significant for intoxication and abnormal GGT values after adjustment for gender, race, Medicaid status, and mechanism of injury.

CONCLUSION

Alcohol abuse is associated with an increased risk of readmission for new trauma. Trauma patients should be screened for alcohol problems; referral of problem drinkers for appropriate care may decrease their risk of admission for subsequent trauma.

Population-based study of fall injuries in children and adolescents resulting in hospitalization or death

OBJECTIVE

To determine the incidence and characteristics of fall-related injuries to children and adolescents.

DESIGN

Population-based study.

SETTING

All hospital discharges in Washington State for fall-related injuries in 1989 and 1990.

POPULATION

Children and adolescents 19 years and younger.

RESULTS

Falls accounted for nearly one third of all trauma admissions, and fall patients tended to be younger than those with other injuries. Falls from one level to another accounted for 40% of the total. One fourth of all patients and 42% of preschoolers sustained head injury. The annual cost of these injuries in Washington State was $4.5 million.

Racial misclassification of American Indians: its effect on injury rates in Oregon, 1989 through 1990

OBJECTIVES

We assessed the extent to which injury rates among American Indians in Oregon are underestimated owing to misclassification of race in a surveillance system.

METHODS

The Oregon Injury Registry, a population-based surveillance system, was linked with the Indian Health Service patient registration file from Oregon, and injury rates for American Indians were calculated before and after correcting for racial misclassification.

RESULTS

In 1989 and 1990, 301 persons in the Oregon registry were coded as American Indian. An additional 89 injured persons who were coded as a race other than American Indian in the registry were listed as American Indian in the Indian Health Service records. The age-adjusted annual injury rate for health service-registered American Indians was 6.9/1000, 68% higher than the rate calculated before data linkage. American Indian ancestry, female sex, and residence in metropolitan counties were associated with a higher likelihood of concordant racial classification in both data sets.

CONCLUSION

Injury rates among American Indians in an Oregon surveillance system are substantially underestimated owing to racial misclassification. Linkage of disease registries and vital records with Indian Health Service records in other states may improve health-related data regarding American Indians.

Prior injury and motor vehicle crash as risk factors for youth suicide

We conducted a case-control study to determine whether adolescents and young adults who have been in a motor vehicle crash or hospitalized for unintentional and intentional injury are at greater risk for suicide. Cases were 700 Washington State residents age 16-35 with a driver's license who died of suicide during 1987-1989. Controls were 3,494 licensed drivers matched by age, sex, and zip code. Using two different databases, we were able to determine the past incidence of in-state injury hospitalizations and motor vehicle crashes for all subjects. Overall, the incidence of suicide was tenfold higher among those with a past hospitalization for injury. Many of these admissions were for suicide attempts [odds ratio (OR) = 56, 95% confidence interval (CI) = 27-120], but the risk of suicide was also higher among those hospitalized for unintentional injuries (OR = 5.0, 95% CI = 2.2-11.5) and assaults (OR = 4.5, 95% CI = 1.1-18). The relative risk for suicide was 2.7 (95% CI = 2.0-3.5) for those with prior injury as a driver in a motor vehicle crash and 2.9 (95% CI = 2.2-3.8) for those with involvement in a single vehicle crash. Many unintentional injury hospitalizations and a proportion of motor vehicle crashes in younger adults may represent unrecognized suicide attempts.

Effect of corticosteroid administration in ischemia--ischemic injury

In order to study the preservation of ischemic tissue, an in vivo end-artery model was designed using the rabbit ear. Ear surface-area necrosis and ear edema were quantitatively evaluated for 14 postoperative days in a total of 107 rabbits. The LD50 of ischemic injury was determined by effecting 8, 10, and 12 hours of circulatory arrest. Using a 12-hour ischemic interval in this model, methylprednisolone decreased edema formation (p less than 0.01) and dramatically halted the progression of ischemic injury to necrosis (p less than 0.05) when administered within 5 hours after the onset of ischemia and continued for 3 postoperative days. A single perioperative dose of methylprednisolone was ineffective in decreasing edema formation and preserving tissue. Administration of steroids greater than 5 hours after the onset of ischemia was similarly ineffective even when administered for 3 postoperative days.

Salvage of ischemic rabbit ear by BW-755C and steroids, but not by indomethacin

The effects of anti-inflammatory steroids and BW-755C (both of which inhibit the formation of prostaglandins and leukotrienes) were studied in ischemia-induced edema and necrosis of the rabbit ear utilizing an occlusion reperfusion model. The results were compared with cyclooxygenase inhibitors which selectively block the synthesis of prostaglandins without affecting leukotriene production. Significant inhibition of the progression of necrosis was observed with both methyl prednisolone and BW-755C. The cyclooxygenase inhibitors, naproxen and low-dose indomethacin had no effect on the progression of ear necrosis. By contrast, high-dose indomethacin significantly inhibited edema but accelerated the progression of necrosis.

Relation of colloid concentration to volume expansion for resuscitation of rats subjected to intestinal ischemic shock

This study was undertaken to determine the volumes of colloids (albumin and dextran 40) with concentrations varying from 0% (Ringer's solution) to 10% solutions required to obtain the same hemodilution. Shock was produced in rats by exteriorization of the small intestine with added complete occlusion of the superior mesenteric vessels with a rubber clamp. After 1 h the clamp was removed, the intestines returned, and the abdomen closed. Over a 6-h period, the fluids were infused continuously in volumes needed to maintain similar hematocrit. Each concentration was given over a wide range of volumes in order to obtain volume-hematocrit curves. Based on these curves, the effect of varying colloid concentration on blood volume expansion was calculated. Albumin and dextran 40 had similar volume expansion/g colloid substance regardless of concentration. When hematocrit of 50% was chosen, as an arbitrary endpoint for volume infusion, the colloid concentration in relation to volume required to be infused is expressed by the equation F50 (formula: see text) where C = colloid concentration and where F50 is the volume factor, or the number of times the volume required for a 10% solution, when a 10% solution is given the volume factor of 1. This relationship is now being used to find the optimal colloid concentration with regard to survival rate in animals subjected to the same intestinal shock.