thèse doctorat de l'université bordeaux 2 - ISPED-Enseignement à ...

MethodsThe study setting was 196-km long Karachi-Hala road section (km 16 to km 212 fromKarachi city centre). This is a four-lane highway, two lanes in each direction. The lanes areseparated by a ground surface, but there are no physical barriers. It has one of the highesttraffic counts in the province, with over 24,000 vehicles per day [83]. This high traffic countcan be explained by the economic activity in Karachi, the most populous city of Pakistan,which accounts for 70% of the government’s revenue through trade and industry [84]. In thisretrospective study, information on traffic injuries reported to Police, ambulance service, andED during 2008 (Jan to Dec) was collected and compared.Police dataSince 2004, the National Highway & Motorway Police (NHMP) ensures traffic enforcementon this 196-km long road section. Administratively, this section is considered as Sector I ofSouth-Zone of NHMP and is divided further in four 46- to 51-km-long beats: beat 35 (km 16to 62), beat 34 (63 to 114), beat 33 (115 to 162), and beat 32 (163 to 212). NHMP deploysfour motor vehicles and four patrolling officers in an eight-hour shift on these beats [10].For every crash, a standard accident analysis report is filed by the attending NHMP officer[85]. A copy of this report is kept in the NHMP regional office. Similarly, details on crash andthose involved are recorded on a separate accident register. From these reports and registers,information was principally extracted on time, date, location of crash, and whether it wasfatal, involved injury, or was without injury. Similarly, we extracted information on name,age, sex, outcome (dead; severe injury, defined as transported to hospital; and mild injury,defined as not transported to hospital), and hospital brought to (when available) of thoseinvolved in crashes.Ambulance dataAmbulance records were obtained from Edhi Ambulance Service (EAS) logbooks. EAS is thelargest private philanthropic ambulance service in the world [86]. EAS has been providingambulance service to injury patients on this road section for the last 15-20 years. For thispurpose, EAS has established six ambulance posts, mostly near main towns, to provide care totraffic injury patients. Location of these posts are: 1) Sohrab Goth (12 km from Karachicentre), 2) Karachi toll plaza (km 28), 3) Edhi centre (km 56), 4) Nooriabad (km 94), 5) HalaNaka (km 160), and 6) Hala (km 212). This service is freely available to injury patients, andfunds are raised by transporting other patients. Ambulance staff consists of, in most cases,only the driver. A clerk at the post can accompany the driver if he thinks this justified, forinstance in case of crash with multiple patients. Ambulance communicates with emergencypost through wireless system or by cell phone.RTI patients or bystanders can contact the services using the free emergency access number115, which connects them to the main city centre [86]. Information is then transmitted bywireless or cell phone to nearby posts, which finally dispatches the ambulance(s). Afterreaching the scene, attendants separate injured and dead patients. Those severely injured aretransported to the nearest hospital; preference is given to the government hospital if available.All information on the RTI intervention including crash location, RTI patient identity andoutcome is then transmitted by wireless or telephone to the regional centre, which records theinformation in a central log book. We obtained these log books from the regional centre atKarachi. Crash details such as date, time, location, and whether it was fatal or involved injurywere extracted from these books. Similarly, road user details such as name, sex, age, user type(pedestrian, motorcycle rider, or vehicle occupant), and outcome (died, including when the30