Preservatives for postmortem brain tissue in biomechanical testing: A pilot study.

Postmortem human subject (PMHS) studies are essential to brain injury research in motor vehicle safety. However, postmortem deterioration reduces the similarity between postmortem test results and in vivo response in material testing of brain tissue and in biomechanical testing of the whole head. This pilot study explores the effect of potential preservatives on brain tissue breakdown to identify promising preservatives that warrant further investigation. To identify preservatives with potential to slow postmortem degradation, samples from an initial PMHS were refrigerated at 10°C to qualitatively compare tissue breakdown from 58 to 152 h postmortem after storage in candidate solutions. On brain tissue samples from a second PMHS, compressive stiffness was measured on six samples immediately after harvest for comparison to the stiffness of 23 samples that were stored at 10°C in candidate solutions for 24 h after harvest. The candidate solutions were artificial cerebrospinal fluid (ACSF) without preservatives; ACSF with a combination of antibiotics and antifungal agents; ACSF with added sodium bicarbonate; and ACSF with both the antibiotic/antifungal combination and sodium bicarbonate. Results were analyzed using multiple linear regression of specimen stiffness on harvest lobe and storage solution to investigate potential differences in tissue stiffness. Qualitative evaluation suggested that samples stored in a solution that contained both the antibiotic/antifungal combination and sodium bicarbonate exhibited less evidence of tissue breakdown than the samples stored without preservatives or with only one of those preservatives. In compression testing, samples tested immediately after harvest were significantly stiffer than samples tested after 24 h of storage at 10°C in ACSF (difference: -0.27 N/mm, 95% confidence interval (CI): -0.50, -0.05) or ACSF with antibiotics/antifungal agents (difference: -0.32 N/mm, 95% CI: -0.59, -0.04), controlling for harvest lobe. In contrast, the stiffness of samples tested after storage in either solution containing sodium bicarbonate was not significantly different from the stiffness of samples tested at harvest. There was no significant overall difference in the mean tissue stiffness between samples from the frontal and parietal lobes, controlling for storage solution. Given the importance of PMHS studies to brain injury research, any strategy that shows promise for helping to maintain in vivo brain material properties has the potential to improve understanding of brain injury mechanisms and tolerance to head injury and warrants further investigation. These pilot study results suggest that sodium bicarbonate has the potential to reduce the deterioration of brain tissue in biomechanical testing. The results motivate further evaluation of sodium bicarbonate as a preservative for biomechanical testing using additional test subjects, more comprehensive material testing, and evaluation under a broader set of test conditions including in whole-head testing. The effect of antibiotics and antifungal agents on brain tissue stiffness was minimal but may have been limited by the cold storage conditions in this study. Further exploration of the potential for microbial agents to preserve tissue postmortem would benefit from evaluation of the effects of storage temperature.

Racial and ethnic disparities in motor vehicle crash-related outcomes in North Carolina surrounding the COVID-19 pandemic.

Long-term impacts of the COVID-19 pandemic on racial and ethnic disparities in motor vehicle crash (MVC) injuries and death are poorly understood. This study aimed to characterize trends and investigate the heterogeneity of MVC-related disparities in North Carolina across several data sources. Crash reports, emergency department visit records, and death certificates from 2018 to 2021 were used to calculate monthly population-rates of MVC-related public health outcomes. We estimated trendlines using joinpoint regression and compared outcomes across racial and ethnic classifications. MVC and MVC-related injury rates declined in conjunction with NC's stay-at-home order, while rates of severe outcomes remained unimpacted. By December 2021 rates of MVC-related outcomes met or exceeded pre-pandemic levels, with the highest rates observed among non-Hispanic Black individuals. Racial and ethnic disparities in MVC-related outcomes remained prevalent throughout the COVID-19 pandemic. These results highlight the importance of a holistic approach to traffic injury surveillance when assessing the impact of MVCs.

Associations between Adolescent Marijuana Use, Driving after Marijuana Use and Recreational Retail Sale in Colorado, USA.

OBJECTIVE: We investigated associations between the retail distribution of recreational marijuana in Colorado and (i) past 30-day marijuana use and (ii) driving after marijuana use (DAMU) among a representative sample of public high school students using four waves of data from a state surveillance system. METHODS: Past 30-day marijuana use was assessed among all sampled students (n = 85,336). DAMU was assessed among students 15 years or older who indicated driving (n = 47,518). Modified Poisson regression with robust variance estimates was used to estimate prevalence ratios (PR) comparing the pre-distribution (2013) and post-distribution (2015, 2017, 2019) periods for marijuana-related behaviors. Frequency of behavioral engagement was assessed using a multinomial approach. RESULTS: An estimated 20.3% of students engaged in past 30-day marijuana use and 10.5% of student drivers engaged in DAMU. Retail distribution of recreational marijuana was not significantly associated with the prevalence of any marijuana use or DAMU. However, it was associated with 1.16 (95% CI: 1.04-1.29) times the prevalence of using marijuana one or two times in the last 30 days, 1.27 (1.03, 1.55) times the prevalence of DAMU one time, and 0.82 (0.69, 0.98) times the prevalence of DAMU six or more times. No significant associations were observed for the remaining frequency categories. CONCLUSIONS: Approximately 1 in 10 students who drive reported DAMU. Varying prevalence in the frequency of past 30-day marijuana use and DAMU was observed following the retail distribution of recreational marijuana in Colorado. Care should be taken to properly educate adolescent drivers regarding the dangers of DAMU.

Public Health Involvement in United States' Vision Zero Initiatives: A Mixed-Methods Study.

CONTEXT: Vision Zero (VZ) aims to reduce fatalities and serious injuries from road traffic crashes to zero through multidisciplinary coordination. While public health officials are often recognized as critical to VZ, their involvement in VZ across the United States has not been quantified. OBJECTIVE: To explore how United States public health officials were involved in VZ development and implementation. DESIGN: We used a mixed-method design including a quantitative assessment of VZ plans and in-depth interviewing with VZ coordinators. SETTING: United States. PARTICIPANTS: Twenty-two in-depth interviews with municipal (n = 12) and regional (n = 10) VZ coordinators and 43 VZ plans were reviewed. MAIN OUTCOME MEASURE: Public health involvement in VZ development and implementation. RESULTS: In the United States, 64 municipalities and 21 regional entities had first-time VZ plans published between 2014 and 2022. We abstracted a sample of municipal (n = 22) and all (n = 21) regional plans. Most plans described key groups involved in plan development (municipal 81.8%, regional 100%). About two-thirds (67.4%; 59.1% municipal, 76.2% regional) of the plans noted public health officials in the plan development. Most plans described the principles forming the foundation of their plan (83.7%), but few mentioned public health as part of the plan principles (22.7% municipal, 14.3% regional). Public health officials were involved in engaging the community (9.1% municipal, 33.3% regional) and providing data (22.7% municipal, 52.4% regional) for plan development, as documented in the plans. For proposed implementation, public health officials were identified as involved in: community engagement (31.8% municipal, 42.9% regional), sharing/analyzing data (40.9% municipal, 33.3% regional), and identifying/providing funding sources (13.6% municipal, 4.8% regional). The in-depth interviews provided further context and a more detailed understanding of public health involvement in VZ. CONCLUSIONS: Evidence from the VZ plans and interviews provided examples of how public health officials engaged in the development and implementation of VZ initiatives.

Feasibility of linking violent death decedents to prior-month emergency department visits in North Carolina, 2019-2020.

OBJECTIVE: Linking data between violent death decedents and other sources can provide valuable insight, highlighting opportunities for prevention of violent injury. This study investigated the feasibility of linking North Carolina Violent Death Reporting System (NC-VDRS) records with North Carolina Disease Event Tracking and Epidemiologic Collection Tool (NC DETECT) emergency department (ED) visit data to identify prior-month ED visits among this population. METHODS: NC-VDRS death records from 2019 through 2020 were linked to NC DETECT ED visit data from December 2018 through 2020 using a probabilistic linkage approach. Linkage variables included date of birth, age, sex, zip code and county of residence, date of event (death/ED visit) and mechanism of injury. Potential linkable ED visits were filtered to those occurring in the month prior to death and manually reviewed for validity. Linked records were compared with the NC-VDRS study population to assess linkage performance and generalisability. RESULTS: Among the 4768 violent deaths identified, we linked 1340 NC-VDRS records to at least one ED visit in the month prior to death. A higher proportion of decedents dying in medical facilities (ED/outpatient, hospital inpatient, hospice or nursing/long-term care facility) linked to a prior-month visit (80%) relative to those dying in other locations (12%). When stratified by place of death, linked decedents demographically resembled the overall NC-VDRS study population. CONCLUSIONS: Though resource intensive, an NC-VDRS-to-NC DETECT linkage was successful in identifying prior-month ED visits among violent death decedents. This linkage should be leveraged to further analyse ED utilisation prior to violent death, expanding the knowledge base surrounding prevention opportunities for violent injuries.

Motor vehicle-related electric scooter injuries in the US: A descriptive analysis of NEISS data.

INTRODUCTION: The introduction of scooter-share programs across the United States has led to an increased incidence of electronic scooter (e-scooter) injuries presenting to emergency departments (EDs). As legislation begins to push scooters from the sidewalk to the street, injuries resulting from collisions between e-scooters and motor vehicles are an important, but poorly characterized consideration. This study leverages data from a national injury surveillance system to characterize e-scooter versus motor vehicle collisions resulting in ED presentation. METHODS: This study utilizes data from the National Electronic Injury Surveillance System (NEISS). NEISS was queried for e-scooter-related injuries from January 1st, 2015 through December 31st, 2019. Injuries were characterized as motor vehicle-related (MV-involved) or non-motor-vehicle-related (MV-uninvolved) based on a manual review by the study investigators. Weighted tabular analyses were used to characterize both types of e-scooter injuries across demographic, diagnostic, and event-related factors. RESULTS: Over the study period an estimated 60,554 (95% CI: 37,525-84,594) injuries were treated in US EDs. Approximately 19% of these injuries involved motor vehicles. Those sustaining MV-involved injuries were significantly younger (p = 0.01), with a higher proportion of males injured (p = 0.01). Additionally, when compared to MV-uninvolved injuries, a significantly higher proportion of those with MV-involved injuries were admitted to the hospital for treatment (8.8% vs. 14.6%, p < 0.01). MV-involved injuries occurred primarily in the street (96.3%), while MV-uninvolved injuries were split across streets (44.0%), at one's home (~20%), and on public property (~20%) (p < 0.01). CONCLUSIONS: Electric scooter injuries involving a motor vehicle differed from those that did not across several key categories. As e-scooters and motor vehicles start to share the road more frequently, greater consideration should be made regarding how these two modes of transportation interact with each other. The promotion of thoughtful e-scooter legislation and infrastructure changes could help promote safer travel.

Trends in Passenger Seat Belt Use Among High School Students-United States, 1991-2019.

PURPOSE: Despite having the highest risk per miles driven for motor vehicle crash involvement, only 57% of US high school students reported always using a seat belt when riding in a car with another driver in 2019. METHODS: Data from the national Youth Risk Behavior Surveys conducted biennially from 1991 to 2019 were used to assess trends in seat belt use. Modified Poisson regression with robust variance estimates and linear splines was used to examine seat belt use trend changes overall and by gender, race/ethnicity, and grade. RESULTS: From 1991 to 2015, seat belt use was about 3.3% higher each survey cycle compared with the previous survey cycle, adjusting for gender, race/ethnicity, and age. After 2015, seat belt use was about 1.8% lower each survey cycle than the previous survey cycle, adjusting for the same covariates. DISCUSSION: New and effective strategies should be considered for promoting consistent seat belt use among US high school students.