RESUMO
BACKGROUND: Limited data from low- and middle-income countries (LMICs) on the severity of road traffic injuries (RTIs) and their relation to different variables of interest are routinely obtained. Knowledge on this subject relies on evidence from high-income countries, which might not be the same as in LMICs. This information is greatly needed to advance and inform local and regional efforts towards the United Nations' Decade of Action and the Sustainable Development Goals. METHODS: From May 2012 to November 2014, a RTI surveillance system was implemented in two referral hospitals in two Mexican cities, León and Guadalajara, with the objective of exploring the relationship between Injury Severity Score (ISS) and different sociodemographic characteristics of the injured as well as different variables related to the event and the environment. All individuals suffering RTIs who visited the Emergency Rooms (ER) were included after granting informed consent. A Zero-Truncated Negative Binomial Model was employed to explore the statistical association between ISS and variables of interest. RESULTS: 3024 individuals participated in the study: 2185 (72.3%) patients from León and 839 patients (27.7%) from Guadalajara. Being male, in the 20-59 age-group, having less schooling, events occurring in Guadalajara, on Sundays, at night, and arriving at ER via public/private ambulance were all associated with an increased log count of ISS. Found a significant interaction effect (p-value< 0.05) between type of road user and alcohol intake six hours before the accident on severity of the injury (ISS). The use of illicit drugs, cellphones and safety devices during the event showed no association to ISS. CONCLUSIONS: Our study contributes to the statistical analysis of ISS obtained through RTI hospital surveillance systems. Findings might facilitate the development and evaluation of focused interventions to reduce RTIs in vulnerable users, to enhance ER services and prehospital care, and to reduce drink driving.