Global and local road traffic injury epidemiology in children and adolescents

Abstract

Background: Every year around the globe, more than 800,000 children and adolescents under the age of 20 die due to injuries from any cause. Globally, low-and middle-income countries bear a disproportionate 95% of the burden of all childhood injury mortality. There is a paucity of data on all injuries in children and road traffic injuries by type of road users among adolescents particularly from low and middle-income countries. The aim of this thesis is to increase the knowledge on the epidemiology of injuries in children 1-4 years and road traffic injuries in adolescents 10-19 years by type of road users in high-income, upper and lower- middle-income and low-income countries with a focus in Pakistan.

Methods: The studies I and II have an ecological study design and used the database by global burden of disease study for the year 2010 and 1990-2019 respectively. The setting for the studies III and IV is Karachi, city of a lower-middle-income country, Pakistan. The study III is a survey of adolescents about their independent mobility and road traffic injuries and the data for study IV are motorcycle injuries from hospitals.

Results: The highest injury rate was 94 per 100,000 in low-income countries of Sub-Saharan Africa and the lowest injury rate was 6 per 100,000 in the high-income countries of Eastern Europe/Central Asia (Study I). The reduction in mortality rates of adolescents’ road traffic injuries is more prominent in high-income countries than any other income level from 1990 to 2019. For instance, the mortality reduction in pedestrians 15-19 years in HICs was IRR 0.94 (95% CI 0.90 to 0.98) (Study II). Adolescents who had parental permission to cross main roads alone (adjusted odds ratio 1.39; 95% confidence interval 1.04 to 1.86) and who participated in one or more activities outside the home alone on the previous weekend (adjusted odds ratio 2.61; 95% confidence interval 1.42 to 5.13) had higher odds of road traffic injuries (Study III). Motorcyclists aged 13-17 years (adjusted odds ratio 1.25; 95% confidence interval 1.11, 1.42) and 18-19 years (adjusted odds ratio 1.26; 95% confidence interval 1.10, 1.43) had higher odds of severe injury compared to aged 20-24 years (Study IV).

Conclusions: Child injury mortality is unevenly distributed across income level, to the detriment of low-income countries. There are decreasing trends in mortality for all types of road users in adolescents from 1990 to 2019 at all income levels but high-income countries have a larger decrease in mortality rates for all types of road users as compared with any other income level. Adolescents in Karachi who were allowed to cross main roads alone and who had weekend activities on their own were associated with road traffic injuries. In addition, adolescents aged 13-17 and 18-19 years were associated with higher odds of severe road traffic injuries compared to motorcyclists aged 20-24 years in Karachi, Pakistan.