Interventions to reduce pedestrian road traffic injuries: A systematic review of randomized controlled trials, cluster randomized controlled trials, interrupted time-series, and controlled before-after studies

BACKGROUND: Road traffic injuries are among the top ten causes of death globally, with the highest burden in low and middle-income countries, where over a third of deaths occur among pedestrians and cyclists. Several interventions to mitigate the burden among pedestrians have been widely implemented, however, the effectiveness has not been systematically examined. OBJECTIVES: To assess the effectiveness of interventions to reduce road traffic crashes, injuries, hospitalizations and deaths among pedestrians. METHODS: We considered studies that evaluated interventions to reduce road traffic crashes, injuries, hospitalizations and/or deaths among pedestrians. We considered randomized controlled trials, interrupted time-series studies, and controlled before-after studies. We searched MEDLINE, EMBASE, Web of Science, WHO Global Health Index, Health Evidence, Transport Research International Documentation and ClinicalTrials.gov through 31 August 2020, and the reference lists of all included studies. Two reviewers independently screened titles and abstracts and full texts, extracted data and assessed the risk of bias. We summarized findings narratively with text and tables. RESULTS: A total of 69123 unique records were identified through the searches, with 26 of these meeting our eligibility criteria. All except two of these were conducted in high-income countries and most were from urban settings. The majority of studies observed either a clear effect favoring the intervention or an unclear effect potentially favoring the intervention and these included: changes to the road environment (19/27); changes to legislation and enforcement (12/12); and road user behavior/education combined with either changes to the road environment (3/3) or with legislation and enforcement (1/1). A small number of studies observed either a null effect or an effect favoring the control. CONCLUSIONS: Although the highest burden of road traffic injuries exists in LMICs, very few studies have examined the effectiveness of available interventions in these settings. Studies indicate that road environment, legislation and enforcement interventions alone produce positive effects on pedestrian safety. In combination with or with road user behavior/education interventions they are particularly effective in improving pedestrian safety

Polynomial modeling for time-varying systems based on a particle swarm optimization algorithm

In this paper, an effective particle swarm optimization (PSO) is proposed for polynomial models for time varying systems. The basic operations of the proposed PSO are similar to those of the classical PSO except that elements of particles represent arithmetic operations and variables of time-varying models. The performance of the proposed PSO is evaluated by polynomial modeling based on various sets of time-invariant and time-varying data. Results of polynomial modeling in time-varying systems show that the proposed PSO outperforms commonly used modeling methods which have been developed for solving dynamic optimization problems including genetic programming (GP) and dynamic GP. An analysis of the diversity of individuals of populations in the proposed PSO and GP reveals why the proposed PSO obtains better results than those obtained by GP

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Effect of road safety-conscious motorcycle taxi programs on riding behaviors and risk of road traffic crash among motorcycle taxi drivers in Kampala, Uganda

Thesis (Ph.D.)--University of Washington, 2019Background: SafeBoda is a private transportation company that started providing motorcycle taxi services in Kampala in 2015. Prior to the introduction of SafeBoda, motorcycle taxi services in Kampala were entirely provided by independent motorcycle taxi drivers with limited formal training on road safety and proclivity for risky riding behaviors (e.g., driving without protective gear and against traffic). SafeBoda introduced an Uber-like model of motorcycle taxi services where it provides road safety training, protective gear, and vehicle maintenance to its drivers. In addition, its drivers are expected to adhere to a code of conduct (e.g., respect for traffic regulations such as stopping at traffic stops). Penalties for breaking the code of conduct include re-training, suspension, or dismissal. We sought to determine whether helmet use, risk of road traffic crash (RTC), and riding behaviors differed between SafeBoda and regular (i.e., those not enrolled in SafeBoda) motorcycle taxi drivers in Kampala, Uganda. Method: We collected demographic and behavioral data from SafeBoda and regular drivers using: a) computer-assisted personal interview (CAPI), where 400 drivers were asked about their riding behaviors (e.g., helmet and mobile phone use); b) roadside observation questionnaire, where riding behaviors were observed in 3000 boda-boda drivers and their passengers along major roads in Kampala; c) text-based/SMS and telephone interview questionnaires where occurrence of road traffic crash data was collected from 342 drivers every two months for a period of six months; and d) Global Positioning System (GPS) devices where movement patterns and riding data were collected from 60 drivers for a period of 24 hours. Baseline characteristics were compared between SafeBoda and regular drivers using chi-square and t-tests. In addition, we used Poisson and generalized estimating equation models with robust standard errors to model the effect of the SafeBoda program on helmet use and risk of road traffic crash respectively. Results: Across all studies, a higher proportion of SafeBoda drivers than regular drivers engaged in safe riding behaviors. For instance, helmet use among SafeBoda compared to regular drivers was 21 percent points higher (95% CI: 0.15-0.27; p<0.001) based on the CAPI and 45 percent points higher (95% CI: 0.43-0.47; p<0.001) based on roadside observation. Furthermore, compared to regular drivers, SafeBoda drivers were more likely to report having a driver’s license (66.3% vs 33.5%; p<0.001) and a reflective jacket (99.5% vs 50.5%; p<0.001) and were less likely to report driving against traffic (4% vs 45.7%; p<0.001) in the past 30 days. From the follow-up study of 342 drivers for 6 months, there were 85 crashes (31 in SafeBoda and 54 in regular drivers) that occurred during the follow-up. The majority of the 85 crashes (31 in SafeBoda vs 54 in regular drivers) involved either a collision with another motorcycle (27.1%) or a car (63.5%). Speeding (10.6%), faulty brakes (7.1%), and distracted driving (4.7%) were the most frequently reported causes of the crashes. Sixty-nine (81.2%) of the crashes resulted in injury to the driver and 56 (81.2%) of these driver injuries required a visit to a health facility. Of the injuries that required a visit to a health facility, 13 (23.2%) required in-patient care (admission). The median hospitalization time for injuries requiring in-patient care (as of the time of follow-up) was 3 days with a range from 1 day to 30 days. Over the six-month follow-up period, SafeBoda drivers were 39% less likely to be involved in a RTC than regular drivers after adjusting for age, possession of a driver’s license, and education (RR: 0.61, 95% CI: 0.39-0.97, p=0.04). From the GPS study, we found that GPS devices are acceptable and feasible for measuring boda-boda driver movements without any major measurement (e.g., missing data and device failure) and logistical (e.g., installation and retrieval of the devices) issues. The GPS data showed that boda-boda drivers in the study made an average of 31 trips per day (SD = 10.4). The median trip was 3.5 km and lasted on average 9.0 minutes (range 3 minutes to 13.8 minutes). The mean farthest Euclidean distance from the driver’s stage or taxi stand was 5.8 km. The mean speed on a trip was 22.5 km/h. Driving movements within the city did not seem to differ significantly between SafeBoda and regular drivers (they shared similar activity spaces). Even where there were differences, these seem to be quite modest. Conclusion: The SafeBoda program is associated with increased safe riding behaviors and reudced risk of road traffic crash among motorcycle taxi drivers in Kampala. Therefore, the promotion and expansion of such programs may lead to a reduction in morbidity and mortality due to road injuries

Multiple sclerosis genomic map implicates peripheral immune cells and microglia in susceptibility

INTRODUCTION: Multiple sclerosis (MS) is an inflammatory and degenerative disease of the central nervous system (CNS) that often presents in young adults. Over the past decade, certain elements of the genetic architecture of susceptibility have gradually emerged, but most of the genetic risk for MS remained unknown. RATIONALE: Earlier versions of the MS genetic map had highlighted the role of the adaptive arm of the immune system, implicating multiple different T cell subsets. We expanded our knowledge of MS susceptibility by performing a genetic association study in MS that leveraged genotype data from 47,429 MS cases and 68,374 control subjects. We enhanced this analysis with an in-depth and comprehensive evaluation of the functional impact of the susceptibility variants that we uncovered. RESULTS: We identified 233 statistically independent associations with MS susceptibility that are genome-wide significant. The major histocompatibility complex (MHC) contains 32 of these associations, and one, the first MS locus on a sex chromosome, is found in chromosome X. The remaining 200 associations are found in the autosomal non-MHC genome. Our genome-wide partitioning approach and large-scale replication effort allowed the evaluation of other variants that did not meet our strict threshold of significance, such as 416 variants that had evidence of statistical replication but did not reach the level of genome-wide statistical significance. Many of these loci are likely to be true susceptibility loci. The genome-wide and suggestive effects jointly explain ~48% of the estimated heritability for MS. Using atlases of gene expression patterns and epigenomic features, we documented that enrichment for MS susceptibility loci was apparent in many different immune cell types and tissues, whereas there was an absence of enrichment in tissue-level brain profiles. We extended the annotation analyses by analyzing new data generated from human induced pluripotent stem cell–derived neurons as well as from purified primary human astrocytes and microglia, observing that enrichment for MS genes is seen in human microglia, the resident immune cells of the brain, but not in astrocytes or neurons. Further, we have characterized the functional consequences of many MS susceptibility variants by identifying those that influence the expression of nearby genes in immune cells or brain. Last, we applied an ensemble of methods to prioritize 551 putative MS susceptibility genes that may be the target of the MS variants that meet a threshold of genome-wide significance. This extensive list of MS susceptibility genes expands our knowledge more than twofold and highlights processes relating to the development, maturation, and terminal differentiation of B, T, natural killer, and myeloid cells that may contribute to the onset of MS. These analyses focus our attention on a number of different cells in which the function of MS variants should be further investigated. Using reference protein-protein interaction maps, these MS genes can also be assembled into 13 communities of genes encoding proteins that interact with one another; this higher-order architecture begins to assemble groups of susceptibility variants whose functional consequences may converge on certain protein complexes that can be prioritized for further evaluation as targets for MS prevention strategies. CONCLUSION: We report a detailed genetic and genomic map of MS susceptibility, one that explains almost half of this disease’s heritability. We highlight the importance of several cells of the peripheral and brain resident immune systems—implicating both the adaptive and innate arms—in the translation of MS genetic risk into an auto-immune inflammatory process that targets the CNS and triggers a neurodegenerative cascade. In particular, the myeloid component highlights a possible role for microglia that requires further investigation, and the B cell component connects to the narrative of effective B cell–directed therapies in MS. These insights set the stage for a new generation of functional studies to uncover the sequence of molecular events that lead to disease onset. This perspective on the trajectory of disease onset will lay the foundation for developing primary prevention strategies that mitigate the risk of developing MS