Observed relationships between driver and passenger restraint use in the front and rear seats.

OBJECTIVE: Seat belt usage has increased substantially since the 1960s, yet driver use continues to affect passenger usage. Recent observational restraint use findings for Maryland will examine the relationship between driver and passenger usage, including adults and children in the rear seat. METHODS: Analyses were based on observational front and rear seat studies administered in parallel from 2016 to 2019. A statistically rigorous front seat project yielded weighted results among drivers and outboard passengers. A study of adults and children in the rear seat was based on a convenience sample of vehicles. Restraint usage results were presented as frequencies and proportions among occupants with known belt use, along with the 95% confidence interval for overall rates. RESULTS: Overall restraint usage rates averaged 90.9% in the front seat study and 81.1% in the rear seat sample. In vehicles with two front seat occupants and a belted driver, the proportion of belted passengers averaged 93.0% over four years. However, among unbelted drivers, only 41.6% of passengers were belted on average. In the rear seat study, an average of 82.7% were belted in vehicles driven by a restrained driver, differing for children (92.0%) versus adults (70.4%). Analysis of vehicles with an unbelted driver revealed an average of 45.0% of belted rear seat occupants, with a considerable difference for children (65.0%) compared with adults (21.0%). CONCLUSIONS: Observational seat belt studies in Maryland in recent years have shown that, despite overall rates above 80%, passenger use in both the front and rear seats is associated with driver restraint use.

Surrogate testing of oral third-generation cephalosporin susceptibility to common uropathogens.

Cefazolin susceptibility of urine isolates of Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis predicts susceptibility to oral cephalosporins, but cefazolin-resistant isolates may be susceptible to oral third-generation cephalosporins. Among 194 urine isolates, we found >95% categorical agreement among oral third-generation cephalosporins. Surrogate testing of cefpodoxime for cefdinir, and vice versa, resulted in no major or very major errors, while combinations involving cefixime produced rare major and very major errors.

Motorcycle helmet effectiveness in reducing head, face and brain injuries by state and helmet law.

BACKGROUND: Despite evidence that motorcycle helmets reduce morbidity and mortality, helmet laws and rates of helmet use vary by state in the U.S. METHODS: We pooled data from eleven states: five with universal laws requiring all motorcyclists to wear a helmet, and six with partial laws requiring only a subset of motorcyclists to wear a helmet. Data were combined in the Crash Outcome Data Evaluation System's General Use Model and included motorcycle crash records probabilistically linked to emergency department and inpatient discharges for years 2005-2008. Medical outcomes were compared between partial and universal helmet law settings. We estimated adjusted relative risks (RR) and 95 % confidence intervals (CIs) for head, facial, traumatic brain, and moderate to severe head/facial injuries associated with helmet use within each helmet law setting using generalized log-binomial regression. RESULTS: Reported helmet use was higher in universal law states (88 % vs. 42 %). Median charges, adjusted for inflation and differences in state-incomes, were higher in partial law states (emergency department $1987 vs. $1443; inpatient $31,506 vs. $25,949). Injuries to the head and face, including traumatic brain injuries, were more common in partial law states. Effectiveness estimates of helmet use were higher in partial law states (adjusted-RR (CI) of head injury: 2.1 (1.9-2.2) partial law single vehicle; 1.4 (1.2, 1.6) universal law single vehicle; 1.8 (1.6-2.0) partial law multi-vehicle; 1.2 (1.1-1.4) universal law multi-vehicle). CONCLUSIONS: Medical charges and rates of head, facial, and brain injuries among motorcyclists were lower in universal law states. Helmets were effective in reducing injury in both helmet law settings; lower effectiveness estimates were observed in universal law states.

Are frailty markers associated with serious thoracic and spinal injuries among motor vehicle crash occupants?

BACKGROUND: While age is a known risk factor in trauma, markers of frailty are growing in their use in the critically ill. Frailty markers may reflect underlying strength and function more than chronologic age, as many modern elderly patients are quite active. However, the optimal markers of frailty are unknown. METHODS: A retrospective review of The Crash Injury Research and Engineering Network (CIREN) database was performed over an 11-year period. Computed tomographic images were analyzed for multiple frailty markers, including sarcopenia determined by psoas muscle area, osteopenia determined by Hounsfield units (HU) of lumbar vertebrae, and vascular disease determined by aortic calcification. RESULTS: Overall, 202 patients were included in the review, with a mean age of 58.5 years. Median Injury Severity Score was 17. Sarcopenia was associated with severe thoracic injury (62.9% vs. 42.5%; p = 0.03). In multivariable analysis controlling for crash severity, sarcopenia remained associated with severe thoracic injury (p = 0.007) and osteopenia was associated with severe spine injury (p = 0.05). While age was not significant in either multivariable analysis, the association of sarcopenia and osteopenia with development of serious injury was more common with older age. CONCLUSIONS: Multiple markers of frailty were associated with severe injury. Frailty may more reflect underlying physiology and injury severity than age, although age is associated with frailty. LEVEL OF EVIDENCE: Prognostic and epidemiologic study, level IV.

A comparison of KABCO and AIS injury severity metrics using CODES linked data.

OBJECTIVE: The research objective is to compare the consistency of distributions between crash assigned (KABCO) and hospital assigned (Abbreviated Injury Scale, AIS) injury severity scoring systems for 2 states. The hypothesis is that AIS scores will be more consistent between the 2 studied states (Maryland and Utah) than KABCO. METHODS: The analysis involved Crash Outcome Data Evaluation System (CODES) data from 2 states, Maryland and Utah, for years 2006-2008. Crash report and hospital inpatient data were linked probabilistically and International Classification of Diseases (CMS 2013) codes from hospital records were translated into AIS codes. KABCO scores from police crash reports were compared to those AIS scores within and between the 2 study states. RESULTS: Maryland appears to have the more severe crash report KABCO scoring for injured crash participants, with close to 50 percent of all injured persons being coded as a level B or worse, and Utah observes approximately 40 percent in this group. When analyzing AIS scores, some fluctuation was seen within states over time, but the distribution of MAIS is much more comparable between states. Maryland had approximately 85 percent of hospitalized injured cases coded as MAIS = 1 or minor. In Utah this percentage was close to 80 percent for all 3 years. This is quite different from the KABCO distributions, where Maryland had a smaller percentage of cases in the lowest injury severity category as compared to Utah. CONCLUSIONS: This analysis examines the distribution of 2 injury severity metrics different in both design and collection and found that both classifications are consistent within each state from 2006 to 2008. However, the distribution of both KABCO and Maximum Abbreviated Injury Scale (MAIS) varies between the states. MAIS was found to be more consistent between states than KABCO.

Changes in the Severity and Injury Sources of Thoracic Aorta Injuries due to Vehicular Crashes.

Research using the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) suggested a decreased adjusted risk of thoracic aorta injuries (TAI) for newer vehicles during near-side crashes and an increased adjusted TAI risk during frontal crashes. This study attempted to explore possible explanations of these findings. Adult front seat occupants in the Crash Injury Research and Engineering Network (CIREN) database through June 2012 were studied. TAI cases were compared with remaining cases in relation to crash and vehicular characteristics. TAI cases of later crash year (CY) (2004-2012) were compared to those in earlier CY (1996-2003) in relation to TAI severity (minor, moderate, severe and non-survivable). TAI cases in newer model year (MY) vehicles (1999-2012) were compared to those in older vehicles (1988-98) in relation to injury source (steering wheel, front, left, seat belt, air bag and other or unknown). Analysis was stratified by direction of impact (frontal and near-side) and the use of restraints. The similar TAI severity of earlier and later CY among frontal crashes suggests that the observed changes in the adjusted odds of injury seen in NASS-CDS are not due to an increase in injury detection. The decrease in TAI severity among newer vehicles in near-side crashes of later CY is consistent with a beneficial effect of crashworthiness improvements for this crash configuration. A shift of injury source in frontal crashes from the steering wheel in older vehicles to "front of vehicle structures", "seat belts" and "unknown and other" in newer vehicles should suggest potential sites for crashworthiness improvements.

Frailty and injury causation.

PURPOSE: : The current study will attempt to elucidate whether frailty has a role in motor vehicle crash injury causation. METHODS: : The association between frailty and injury was studied among Crash Injury Research Engineering Network (CIREN) cases. The baseline "physical functioning" (PF) score of the SF-36 was used as a marker of frailty (i.e., PF score <75). Frailty associations with ISS and occupant, vehicular and crash factors were explored. Frailty association with delta V was analyzed among injured (i.e., brain, rib, or femur) belted occupants in frontal crashes to establish whether frailty confers a different risk of each particular injury. RESULTS: : Frailty occurred in 13.7 % of the cohort (n=1,747). Median (q1-q3) ISS was 14.0 (10-22) among the frail and 17.0 (10-24) among the non frail (p=0.40). Frailty was significantly associated with advanced age, male gender, the presence of co-morbidities, extreme BMIs, frontal and near-side crashes and delta V < 45 km/h. Seat belt use and ISS<16 were not associated with frailty. Multiple linear regressions, adjusting for age, gender and BMI revealed a negative association between frailty and log delta V (coefficient -0.188, p=0.04) among those with rib fractures but not among those with brain injuries or femur fractures. CONCLUSION: : PF score, a marker of frailty, is associated with similar ISS and lower delta V and is independently linked to lower delta V thresholds for some injuries (i.e. rib fractures) but not for others (i.e. brain injuries and femur fractures). These associations suggest a potential role of frailty in injury causation.

Pursuit of Licensure by Senior Drivers Referred by Police to a State Licensing Agency's Medical Advisory Board.

In all fifty United States and the District of Columbia, police Requests for Re-examination (RRE) concerning fitness to driver are accepted by licensing agencies. This study assessed licensing outcomes of senior drivers, ≥75 years of age, who had RREs submitted to the Medical Advisory Board (MAB) of a Maryland Motor Vehicle Administration from March 2005 through April 2007. RRE traffic event information (including crashed, did not crash), driver demographic information, initial MAB recommendations (suspension vs no suspension), driving occupational therapists assessments, and drivers' pursuit of continued licensure were entered into a database. During the period of study, 475 RREs were referred to the MAB. The percent of referred senior drivers (n=240, 50.4%) was similar to that of younger drivers (n=235, 49.5%). A higher percentage of senior drivers retired from driving compared to younger drivers; being, 57.1% vs 23.8% (p <.01), respectively. Further analyses limited to the 240 senior drivers found: 139 (57.9%) were men, 150 (62.5%) were 75-84 years of age, 119 (49.5%) were noted to be disoriented at the traffic scene, 141 (58.8%) were involved in a crash, and 127 (52.9%) were initially suspended as the result of MAB review. The following factors were significantly related to retiring from driving, initial MAB suspension and greater age. Of the 127 drivers who were initially suspended, 82 (64.6%) retired from driving, and 45 (35.4%) pursued further licensure (p <0.01). In contrast, the percentage of non-suspended drivers who did or did not pursue further licensure was similar; being 48.7% vs 51.3%. Among drivers ≥85 years of age, 68.9% retired from driving, compared with 50% of the drivers who were 75 to 84 years of age (p <0.01) While not statisically significant, higher percentages of driving retirement were noted for the following: sex - a greater percentage of men compared to women (61.9% vs 49.5%); confusion at the traffic scene (confused, 57.1% vs non-confused, 42.9%); and crash involvement (56.7% who crashed, retired vs 43.3% of those who did not crash, retired). Overall, the most important finding of this study is that as a result of police referral, only one-fifth (20.4%) of senior drivers 75 years of age or older, continued to maintain their driving privilege. However, only 40 drivers (16.7%) retained their original driving privilege without added restrictions. The data suggest that senior drivers who are not medically fit to drive may be identified by police referrals to a licensing agency. Driving occupational therapy assessments and training, and additional driving restrictions are recommended to facilitate continuation of the driving privilege for some drivers.

Crash test ratings and real-world frontal crash outcomes: a CIREN study.

OBJECTIVE: To establish whether the Insurance Institute for Highway Safety (IIHS) offset crash test ratings are linked to different mortality rates in real world frontal crashes. METHODS: The study used Crash Injury Research Engineering Network drivers of age older than 15 years who were involved in frontal crashes. The Crash Injury Research Engineering Network is a convenience sample of persons injured in crashes with at least one Abbreviated Injury Scale score of 3+ injury or two Abbreviated Injury Scale score of 2+ injuries who were either treated at a Level I trauma center or died. Cases were grouped by IIHS crash test ratings (i.e., good, acceptable, marginal, poor, and not rated). Those rated marginal were excluded because of their small numbers. Mortality rates experienced by these ratings-based groups were compared using the Mantel-Haenszel chi test. Multiple logistic regression models were built to adjust for confounders (i.e., occupant, vehicular, and crash factors). RESULTS: A total of 1,226 cases were distributed within not rated (59%), poor (12%), average (16%), and good (14%) categories. Those rated good and average experienced a lower unadjusted mortality rate. After adjustment by confounders, those in vehicles rated good experienced a lower risk of death (adjusted OR 0.38 [0.16-0.90]) than those in vehicles rated poor. There was no significant effect for "acceptable" rating. Other factors influencing the occurrence of death were age, DeltaV >or=70 km/h, high body mass index, and lack of restraint use. CONCLUSION: After adjusting for occupant, vehicular, and crash factors, drivers of vehicles rated good by the IIHS experienced a lower risk of death in frontal crashes.

The relationship between impaired driving crashes and beliefs about impaired driving: do residents in high crash rate counties have greater concerns about impaired driving?

OBJECTIVES: The purpose of this investigation was to examine the relationship between impaired driving crashes and public beliefs and concerns about impaired driving across each of Maryland's twenty-four counties (including Baltimore City). It was hypothesized that residents of counties that experience higher impaired driving crashes would express more concerns about impaired driving and perceive more risks about driving impaired than residents of counties that have lower rates of impaired driving. METHODS: Data for alcohol impaired driving crashes were obtained for the years 2004-2006. These data were compared to public opinion data that was obtained annually by random-digit-dial telephone surveys from 2004 to 2007. RESULTS: Concerns about drunk driving as well as perceptions of the likelihood of being stopped by the police if one were to drive after having too much to drink were related to counties with higher serious impaired driving crash rates, as were perceptions that the police and the legal system were too lenient. Perceptions about the likelihood of being stopped by the police were higher in those counties with more impaired driving enforcement activity. CONCLUSION: Perceptions of concern appear to be shaped more by crash exposure than enforcement activity. Campaigns that address impaired driving prevention should substantially increase enforcement, strengthen the adjudication process of impaired drivers, and emphasize the potential seriousness of drinking-driving crashes in their promotional activities.

Expected differences and unexpected commonalities in mortality, injury severity, and injury patterns between near versus far occupants of side impact crashes.

OBJECTIVE: To compare injury patterns and outcomes of near- and far-side collisions. METHODS: Near- and far-side occupants in the Crash Injury Research and Engineering Network (CIREN) were compared for mortality and the occurrence of severe injuries (maximum abbreviated injury scale [MAIS] 3+). Regression models, adjusting for confounders, examined death and MAIS 3+ injuries as outcomes and near- or far-side position as an independent variable. CIREN findings were compared with those of the Crash Outcome Data Evaluation System (CODES), and the Maryland Automated Accident Reporting System. RESULTS: Of the 380 cases, 72% were in the near and 28% in the far position. Mortality was similar between groups within CIREN. Near-side occupants experienced a higher frequency of MAIS 3+ injuries for the thorax, abdomen, and lower extremities, and fewer MAIS 3+ head injuries than far-side occupants (35% vs. 46%, p = 0.06). Regression models revealed similar risk of MAIS 3+ head injuries among near- and far-side occupants. The most common structures contacting the head in far-side crashes (N = 62) were opposite side structures (52%) and other occupants (13%). Similar risks of head injuries among near- and far-side occupants were observed for the CODES data; however, lower risks of death were present among far-side drivers involved in crashes, based on CODES and Maryland Automated Accident Reporting System. CONCLUSIONS: Despite a lower incidence of thoracic, abdominal, and lower extremity injuries, far-side occupants experienced a similar risk of head injuries to that of near-side occupants. Contact patterns suggest that restraint systems fail to keep far-side occupants' heads from striking opposite side structures or other occupants.

Police referral of drivers to the Maryland Motor Vehicle Administration's Medical Advisory Board.

In the 50 United States and the District of Columbia law enforcement medical referrals are accepted by licensing agencies. This study assessed driving actions, medical concerns, and medical conditions in 486 police referrals to the Medical Advisory Board of the Maryland Motor Vehicle Administration during a 25-month period. Driving actions, medical concerns, and medical conditions were grouped into categories and entered into a database. These elements were analyzed relative to driver age and sex. In addition, the issuance of citations for driving violations was studied relative to age and sex. A greater percentage of drivers 60 years of age or greater (senior adults) were referred compared to the general population of licensed drivers that age, being 71.4% vs 20.6% (p <0.01). Crashing, the most common driving action, was not associated with age or sex. Among driving actions frequently mentioned relative to older drivers, only confusion of pedals was associated with senior adults drivers as compared to younger drivers (6.1% vs 0.1%, p <0.01). Of the most frequently mentioned medical concerns, confusion/disorientation was associated with being a senior adult (p <0.01), while loss of consciousness was associated with younger drivers (p <0.01). The most frequently mentioned medical conditions, diabetes and seizure, were associated with being under 60 years of age. All mentions of dementia were in senior adult drivers. Compared with younger drivers, drivers 60 years of age or older, were less often summoned for driving violations, being 33.0% vs 53.5% (p <0.01), respectively. The threshold for the issuance of fewer citations was lower for men (40 to 59 years of age) compared to women (60 years of age or greater). Studies are needed to correlate specific traffic violations and/or crashes to specific medical conditions.

Aging is not a risk factor for femoral and tibial fractures in motor vehicle crashes.

OBJECTIVE: To determine the effect of aging on the occurrence of femoral and tibial fractures during vehicular crashes. METHODS: The Crash Injury Research and Engineering Network (CIREN), which includes occupants of a vehicle < 8 years old with at least one AIS > or = 3 or two AIS > or = 2 injuries in different body regions, comprised the study population. The occurrence of femoral and tibial fractures during vehicular crashes was analyzed in relation to age and other confounders [gender, BMI, stature, change in velocity (Deltav), restraint use, occupant position (driver vs. passenger) and principal direction of force (PDOF)] using chi2, Mantel-Haenszel chi2 and student t test. Multiple logistic regression (MLR) models were built for the prediction of femoral and tibial fractures with age as the independent variable and possible confounders as co-variates. An alpha = 0.05 was used for all statistics. RESULTS: The incidence of femoral and tibial fractures in the study population (N=1,418) was 23% and 27%, respectively. Univariate analyses revealed a negative association between increasing age and femoral fractures and no association between age and tibial fractures. MLR models revealed no clear effect of increasing age on the occurrence of either femoral or tibial fractures. Obesity, frontal PDOF, and high Deltav affected the occurrence of femoral fractures. Tibial fractures were influenced by occupant position (driver), frontal PDOF, high Deltav and shorter stature. CONCLUSION: Despite the known changes in bone composition and strength with aging, elderly vehicular occupants do not experience higher odds of incurring femoral and tibial fractures during crashes.

Delta V, principal direction of force, and restraint use contributions to motor vehicle crash mortality.

OBJECTIVE: To measure the combined contribution of change in velocity (Deltav), principal direction of force (PDOF), and restraint use on mortality after vehicular trauma. METHODS: The Crash Injury Research and Engineering Network population includes patients <8 years old with one injury with an Abbreviated Injury Scale score >or=3 or with two injuries with an Abbreviated Injury Scale score >or=2, who were occupants of a vehicle. Patients 15 years or younger; in rear collisions; back seat occupants; in crashes with Deltav >80 km/h, unknown Deltav, or unknown PDOF; or in vehicles without airbags were excluded. Mortality was analyzed in relation to Deltav (km/h), restraint use, and PDOF using chi2. Multiple logistic regression models were built, including possible confounders (body mass index, age, gender) and interactions were explored. An [alpha] = 0.05 was used for all statistics. RESULTS: A total of 1,261 cases were included. Mortality was higher for unrestrained than for restrained patients (17% vs. 9%) and was higher for lateral than for frontal impact patients (17% vs. 11%). Higher mortality rates were also observed for Deltav 40-80 km/h than for Deltav <40 km/h (17% vs. 9%). Multiple logistic regression findings, after adjusting for age, gender, and body mass index, revealed significant effects of lateral PDOF (odds ratio [OR] 3.06 [2.03-4.61]), unrestrained status (OR 2.95 [2.01-4.38]), and Deltav 40-80 km/h (OR 3.65 [2.44-5.44]). Effect modification was found between PDOF and Deltav. CONCLUSIONS: A Deltav 40 km/h to 80 km/h, lack of restraint use, and lateral impact significantly affects mortality. A synergistic effect was found between Deltav 40-80 km/h and lateral PDOF.

The association between age, injury, and survival to hospital among a cohort of injured motorcyclists.

Despite the significant increase in mortality among older motorcyclists during the past decade, few studies have addressed specific injuries or mortality rates among all those injured. The purpose of this study is to describe the crash and injury characteristics among a cohort of motorcyclists injured in Maryland, and to determine the influence of age and crash type on mortality, injury patterns, and place of death (scene vs. hospital). Possible biases introduced by studying only those hospitalized are described. Based on the findings, specific injury prevention strategies for older vs. younger riders are proposed.

Life-altering outcomes after lower extremity injury sustained in motor vehicle crashes.

BACKGROUND: Lower extremity injuries (LEIs) sustained in vehicular crashes result in physical problems and unexpected psychosocial consequences. Their significance is diminished by low Abbreviated Injury Scale scores. METHODS: Drivers who sustained LEIs were identified as part of the Crash Injury Research and Engineering Network (CIREN) and interviewed during hospitalization, at 6 months, and at 1 year. All were occupants of newer vehicles with seatbelts and airbags. RESULTS: Sixty-five patients were followed for 1 year. Injuries included mild brain injury (43%), ankle/foot fractures (55%), and bilateral injuries (37%). One year post-injury, 46% reported limitations in walking and 22% with ankle/foot fractures were unable to return to work. Depression (39%), cognitive problems (32%), and post-traumatic stress disorder (18%) were significant in the mild brain injury group. CONCLUSIONS: Long-lasting physical and psychological burdens may impede recovery and alter the lifestyle of patients with LEI. These issues need to be addressed by trauma center personnel.

Psychosocial and physical factors associated with lower extremity injury.

With the increasing availability of modern occupant restraints, more drivers and passengers are surviving high-energy crashes. However, a large number, especially those involved in frontal and offset frontal crashes, incur disabling lower extremity injuries. In the past, not much attention was paid to these injuries, as they were usually not life threatening. Despite the low AIS scores associated with injuries to the lower extremities, they pose a major physical and psychological burden on patients' and their ability to return to pre-crash functioning. Associated injuries, such as mild brain injuries, and psychosocial factors such as depression, also influence the long-term outcome.