Bigdeli et al. BMC Public Health 2010, 10:406 http://www.biomedcentral.com/1471-2458/10/406 crashes and injuries and they may require longer extri- cation times, a result which is line with Grossman et al. [19]. The transport interval in this study was shorter than at other settings in Iran, 10.5 minutes compare to 18.5 in Tehran [23]. The reason for this again may mainly be related to the infrastructure of the city and the availabil- ity of different hospitals combined with low traffic con- gestion; factors which can provide better conditions for victim transportation. It is important to note that the response time interval on interurban roads was signifi- cantly longer than that within the city. However, com- pared to the transport interval, this variation was lower. This may imply, on the one hand, that the location of the ambulance dispatch sites allows ambulances to arrive at crash scenes more quickly and hence provide better ambulance access to victims, but, on the other hand, that it takes longer for them to transport victims to hospital. As a result of this comparison, information regarding the effect of time on outcomes may be helpful in decisions on the geographic location of transport and first response teams as well as the sites for ambulance dispatch. In general, the total pre-hospital time interval in this study was 37.2 minutes. Focusing on this time interval, when it is stratified by crash occurrence in the city and on interurban roads, it was 29.2 and 45.0 minutes, respectively. Compared to a study in Tehran, our finding was low, 37.2 vs. 45.0 minutes. As explained earlier regarding the response time interval, the same reason could be considered for this difference. Moreover, in recent years, the EMS have dramatically improved in the country as a whole [24], including an increase in the number of ambulances and ambulance dispatch sites, improvements in the equipment, and educational plans for emergency team staff [22]. All these factors can affect the shorter response as well as total pre-hospital time intervals. As Calland (2005) noted that “ the term Golden Hour, i.e. the first 60 minutes after crash occurrence, was first introduced in 1961, but due to misinterpretation as to what period this actually referred to, a second concept, the “Platinum Ten Minutes” was proposed as the time taken to move a victim to the ambulance. To achieve this rapid removal, the ambulance and medical person- nel must work in harmony with the police and fire ser- vice to secure the scene and remove the RTI victims safely without causing injury either to the casualty or other personnel on the scene”. Currently there is no available information about the notification interval in this study, however as Figure 1 shows, this time interval is a hidden part of the total interval and it is crucial to the eventual outcome of each dispatch. This interval may be affected by many Page 6 of 7 factors other than improvement in the pre-hospital care. A study in Tehran revealed that the mean time between the crash occurrence and arrival at the hospital was 170 minutes, while the total time interval from notification to arrival hospital was 120 minutes [21]. This difference between injury occurrence and notification time can argue for the importance of evaluation of the notifica- tion interval in Iranian settings through establishment of injury surveillance [22], which currently is underway. Limitation and strength of the study Accuracy when filling in the data on the questionnaire is one issue. However, data are collected by the trained personnel in the EMS and authors recommend quality control on the data collection process. The future lim- itation of the study concerns focusing on time intervals and not on quality of care. From the data at hand we could focus on that part of data rather than the severity of the injury and a lack of analysis of potential correla- tions between injury type and severity. However, they were not within the scope of this study. Another limita- tion concerns the removal of 187 cases from the list, because of their incomplete data for analysis. We criti- cally tested using the available information at hand and there was no skew and significant variation between this data with that presented in the tables. A strength of this study was that, to our knowledge, it was the first in the country that compared city and interurban roads and the associations and differences for various time inter- vals, using all cases for a period of two years. Conclusion All time intervals among accident victims on interurban road areas are longer than those for city areas. The short response interval and transport interval compared to other settings may indicate improvement in the pre- hospital services in the study area. It is important for more attention and care to be paid to the notification interval which should be measured by means of the establishment of a surveillance system at the EMS. A public education campaign to increase cooperation is also an important recommendation of this study. Finally, this study implies the need for investigation of the need-for and access-to emergency medical services [15,25]. Acknowledgements This study was approved and sponsored by the Urmia University of Medical Sciences both financially and administratively. Special thanks to colleagues at Vice Chancellor of Treatment in Urmia University of Medical Sciences for their contribution and providing facilities for data collection