Background

The beginning of the road traffic accident (RTA) problem started before the introduction of cars; but the problem intensified with the invention of vehicles. According to the world health organization fact sheets published in June 2022 [1], about 1.3 million people succumb to road traffic accidents each year, with 93% of the deaths occurring in Low and Middle Income Countries (LMICs). Furthermore a recent evaluation of WHO trends [2] predicted RTAs to be the seventh main cause of deaths by 2030 unless action is taken. Thus, the incidence of RTA is on the rise contributing to the global burden of mortality as a major global health threat [3].

According to Jayaraman et al. at Mulago National Referral Hospital, death due to RTAs accounted for half of the total deaths with majority dying within 24 h. Over the last 25 years, RTA related deaths in Uganda have risen seven-fold with an accident severity index of 24 deaths per 100 road crashes, an average of 10 people dying per day, which is the highest rate in the East African community [4, 16]. The majority of this group is more prone to be engaged in high-risk activities such as reckless riding, over-speeding, overloading, and riding while intoxicated and riding without any protective equipment which increases the risk of RTAs.

It was observed in this study that the most common road user category was motorcyclists accounting for 48.8% of the study participants. This is in accordance with a study by Chandrasekharan [17]. However, other studies showed different findings like Sisimwo et al. [15] and Kourouma et al. [18] who found pedestrians and passengers to be the most commonly injured. The large number of motorcyclists injured can be linked to the fact that motorcycles being two-wheeler have a lower stability compared to motor vehicles. The other possible reason could be because they have been reported to ignore most of the traffic rules that could keep them safe despite the low stability of the motorcycles [19]. Also, casualties among pedestrians (30.8%) could be explained by the lack of segregated pedestrian road networks and the lack of community understanding about road safety.

The incidence of early mortality in this study was relatively high (14.69%) and comparable with the LMICs’ rates as reported by WHO [2]. Tra et al. [14] in Korea observed also a high early mortality rate of 29.4% among road traffic accident victims. Huei et al. [20] and Kang et al. [12] reported a 10.8% and an 11.9% early mortality rate among patients with severe hemorrhagic shock due to trauma respectively. The differences seen in the mortality could be explained by the levels of care among other factors that may be study population or patient specific.

The only significant pre-hospital predictor of 24 h mortality was the category of road user, in which motorcycle riders were 5.9 times more likely to die compared to pedestrians. This is in agreement with the findings by Chandrasekharan [17], in which casualty fatalities were more common among motorcycle riders as compared to pedestrians. In contradiction to our findings, Derry, Palk and King [21] found that pedestrians had a 3 times higher relative risk of mortality than drivers or riders, and that being a driver or rider of any sort of vehicle was a protective factor against RTAs and fatalities when compared to being a pedestrian. The explanation to our findings is possibly because of the momentum of impact that increases the severity of injury among motorcycle riders who are likely to be at a higher speed compared to pedestrians.

In this study we used Kampala trauma score II (KTS II) to assess severity of injury and our findings showed that the severity of injury graded by KTS II was associated with 24 h mortality (p < 0.001). This is in line with earlier research, which suggested that severity of injury has a strong relationship with mortality rate [22, 23]. Weeks et al. [24] demonstrated in their study that the KTS II is as good as other grading systems at predicting patient mortality in resource limited settings.

Although studies have demonstrated type of injury (blunt and penetrating injuries) to be associated with mortality in trauma patients [20, 25] in this study, it was not statistically significant. The time to first aid, emergency unit workers and being trained on trauma care were also not significantly associated to early mortality in this study. The fact that we only assessed for 24 h mortality could explain the differences in our findings in relation to predictors since other studies did follow up for a longer period.

Study limitations

Patients with minor injuries who did not seek treatment in the study sites were not identified. Also deaths that occurred on the scene or during transportation of the patient to hospital were not captured. In addition, follow-up stopped at 24 h and so deaths that occurred after 24 h were not captured.

Conclusion and recommendations

The incidence of 24 h mortality among road traffic accident victims was high and being a motorcycle rider and severity of injury according to Kampala trauma score II predicted mortality. Therefore, motorcyclists should be reminded to be more careful while using the road. Trauma patients should be assessed for severity using KTS II, and the findings used to guide management.

We also recommend that a large non-hospital based cohort study of trauma patients be carried out and a follow-up of more than 24 h instituted in order to identify more predictors of mortality due to road accidents in our setting without excluding any patients.