Globally, road traffic injuries are ranked ninth among the leading causes of disability adjusted life years lost, and their ranking is projected to rise to third by 2020. Moreover, 96% of all children killed worldwide are due to road traffic accidents. ^{(3, 4)}

The problem is increasing at a fast rate in developing countries due to rapid motorization and other factors. Road traffic injuries in developing countries particularly affect the productive age group (15–44 years) and children among whom the fatality rates are especially high. With incomplete, little or no data available from countries with higher RTI mortality rates, there is also a suggestion that the present global RTI burden is underestimated. ^{(5, 6)}

In Saudi Arabia, with its rapid expansion of road construction and increase in the number of vehicles, road traffic accidents are becoming a serious public health problem. The ensuing trauma has increased in direct proportion to the increase in the number of road vehicles. Mortality rates have also increased substantially since 1990 due to road traffic accidents. This accounts for 4.7%, of all mortalities while it does not exceed 1.7% in each of Australia, England and America. Latest statistics indicate that, 12 deaths occur daily in Saudi Arabia due to traffic accidents. ⁽⁷⁾ The Secretary General of the Shura Council, declared that the Kingdom spent on the four million car accident annually about 26 billion riyals, and added: “The Kingdom is at the forefront of the world in terms of human and physical attrition due to traffic accidents. ⁽⁸⁾

In Saudi Arabia the data on the number of accidents, injuries and deaths, are recorded in police reports, where they are designed for legal instead of medical purposes. These data report very little information on the health consequences of the people involved in road traffic Injuries. Another source of information about accidents RTA can be obtained from the existing health information systems (hospital discharge reports). Although this health system data include detailed health information, they are not related or linked to the data obtained by the traffic police department.

Examining the consistency of these sources is vital to build an accurate surveillance system that can track the circumstances of a traffic accident, the risk factors and the medical consequences, as well as establishing and evaluating prevention interventions.

The inconsistencies described in this study may reflect to some extent the use of different definitions for a road traffic death leading to underreporting of road traffic-related deaths in police records. In addition to differences in definitions, this may reflect differences in data collection methods. For example, in western Scotland, 45% of hospital admissions due to road traffic injuries were not recorded by the police. ⁽⁹⁾ Loo et al. have reported that in the Hong Kong, the police-reported road accidents rate was only 58–60% of the actual rate, and that underreporting was particularly high for children (reporting rate of 34%) and cyclists (reporting rate of 33%). ⁽¹⁰⁾ In another study, some road traffic injuries were not reported to the police mainly because, according to respondents, it was “not necessary” or the incident was a “hit and run case”. ⁽¹¹⁾ Others have suggested that road traffic officials may be underreporting RTA statistics to avoid criticism from superiors who expect to see rates go down. ⁽¹²⁾

Knowing the actual number of road traffic fatalities is essential for planning realistic policies aimed at reducing these deaths. The inconsistency between police-reported data and death registration data strongly suggests that: (i) Local and national organizations should interpret RTA statistics cautiously; and (ii) Police departments should improve the quality of their data by adopting a definition of “road traffic death” that is based on the international classification of diseases (ICD). Also, (iii) Police departments should integrate multiple data sources when estimating the burden of road traffic injuries and deaths. ⁽¹³⁾ In conclusion, the inconsistencies between the rate of death from road traffic deaths based on police-reported data and on health registration data strongly suggest that there is underreporting of road accidents’ fatalities from the police departments. Active efforts to audit and monitor data quality, even if only in periodic or sample surveys, are necessary.

In this study, a population survey representative of the 5–49 years age group in Qassim was done. The results of this survey showed that nearly 1 in 14 people reported non-fatal RTI annually requiring a recovery period of >7 days, and nearly 1 in 7 people reported non-fatal RTI annually requiring recovery period of ≤ 7 days. An estimated 38 and 35 per 100,000 people die and are disabled due to RTA each year, respectively. The annual incidence of RTI requiring less than 7 days of recovery was 13%, while the annual incidence of RTI requiring more than 7 days of recovery was 7% in this population. These findings suggest that the magnitude of RTI is high, and is higher than that reported from other developing countries. ^(14–19)

We examined some possible reasons for this. The majority of the previously published population-based studies on RTI incidence from other countries have reported data that had resulted in loss of activities using 12-months recall period, and most of these had reported proxy data. In order to get a more comprehensive picture of RTI, we documented all RTI irrespective of the severity or the number of days of loss of activity. We did not use proxy data but collected data directly from all eligible participants in the population surveys except those 5–15 years old. We used a recall period of three-months to estimate the annual incidence of non-fatal RTI as recall bias is a major limitation for data on non-fatal injuries, and less severe injuries in particular are underestimated with longer recall periods.^{(20, 21)} Our data show that the decline in RTI incidence from 3- to 12-months recall period was 51.8%.

The study also recognized multiple RTI during the recall period in the same participant. Injuries may be clustered in some individuals. ⁽²²⁾ During the development and testing of the study questionnaire, it was observed that some events were not considered RTA by participants. Therefore, each participant was explained the definition of RTA and RTI to ensure that the information on these were not missed. This has resulted in better RTI estimates.

The burden of RTI in Qassim area was enormous. This burden was highest in young males. The over representation of young adults and males has been documented previously and is possibly related to their differential exposure to risky behaviors. ^{(1, 23–25)} Interestingly, the non-fatal RTI incidence was similar between 2 groups of monthly income for RTI requiring recovery period of less than 7days. However, people with lower monthly income had higher incidence for RTI requiring recovery period more than 7 days or more. Socioeconomic status is known to be a risk factor for injury including RTI, and mortality and morbidity rates in vulnerable road users have been reported to be higher in the lower social classes. ^{(1, 26, 27)} However, a cohort study from rural Vietnam did not find poverty either as a risk or protective factor for RTI and the middle income group was exposed to the highest risk of RTI. ⁽²²⁾ We used per capita monthly income as a measure of socioeconomic status; other indicators such as education, occupation and household expenditure have also been used previously. Further research is needed to better understand the complex association of socioeconomic status with RTI.

The annual RTI mortality rate per 100,000 in the 5–49 years age group was 35.4/100,000 (95% CI 16.6 – 57.8). This study was not powered to measure RTI mortality rate as the required sample size for such an assessment would be very large, and the wide confidence interval highlights the importance of a reasonable sample size to arrive at reliable RTI mortality estimates. The point estimate of RTI mortality in Qassim population aged 5–49 years is nearly twice that reported by many other developing countries. ⁽²⁸⁾

The results of this study show that the last three days of the week (Wednesday, Thursday and Friday) had the highest rates of RTA. This could be attributed to the fact that some adolescents and young adults participate in unofficial car races with their peers at the week-ends as a leisure-time activity. In addition, people used to seek relatives’ visits, recreation and shopping during the weekend exposing themselves to the risk of RTA.