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

BACKGROUNDPakistan, located at the junction of Middle-East, South-East, and Central Asia , is the sixthmost populous nation of the world [1]. According to transport authorities, approximately 1.4million Road Traffic Crashes (RTCs) occurred in Pakistan in 1999, resulting in over 7 000fatalities [2]. Two independent population-based surveys estimated incidence of Road TrafficInjuries (RTIs) around 15 to 17 per 1 000 persons per year [3, 4]. These injuries contributesignificantly to the workload in hospitals, leading to direct costs of over 1 billon US$ to thePakistani economy [5, 6].Interurban road sections are the backbone of Pakistani economy. Its strategic road network ofapproximately 8 000 km plays a significant role in transport, as it carries more than 80% ofinland passenger and freight traffic [2, 7]. Although these road sections account for 4% of theentire network, they account for a high proportion of traffic fatalities (27%) [8]. Previousresearch in Pakistan has shown that injury severity was higher for crashes in rural areas, butno distinction was made between interurban or other rural roads [9]. Higher speeds, presenceof vulnerable road users, and complex road traffic conditions can explain this high fatalityratio, but no comparison indicators were available for these road sections [10].Police records remain, to date, the most used source for evaluating interurban traffic safety,because of geographical distances and complexity of trauma care in such settings [9, 11]. Theuse of these statistics only, however, can lead to underestimation of RTI burden in Low- andMiddle-Income Countries (LMICs) like Pakistan [12]. A recent World Health Organization(WHO) report showed that actual traffic fatalities could be 4 to 10 times higher than theofficial statistics in Pakistan [13]. A previous study in Karachi city showed that police recordsaccounted for only 56% of traffic fatalities and 4% of such severe injuries [14]. No notableresearch has been carried out to compare the differences in injury reporting by linkingdifferent datasets for interurban road settings in Pakistan [12, 13]. The World Bank reportedthat interventions with proven effectiveness exist but their implementations are impeded bythe lack of documenting the specific disease burden in LMICs [15]. The objective of thisstudy were to assess differences in crash and injury reporting between police, ambulance, andEmergency Department (ED) datasets on an interurban road section in Pakistan. Further, thesedatasets were linked to assess variations in traffic fatality and injury per vehicle-kilometres(vehicle-km) travelled on the road section.METHODSThe study setting was the 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 [16]. The lanesare separated by a ground surface, but there are no physical barriers. Traffic counts range16 356 to 24 707 vehicles per day on this section [17]. This high traffic count can beexplained by the economic activity in Karachi, the most populous city of Pakistan, whichaccounts for 70% of the government’s revenue through trade and industry [18]. In thisretrospective study, information on traffic injuries reported to highway police, ambulanceservice, and ED during 2008 (Jan to Dec) was collected and compared.Police dataSince 2004, the National Highway & Motorway Police (NHMP) ensures traffic enforcementon this road section. Administratively, this section is considered as Sector I of South-Zone ofNHMP and is divided further in four 46- to 51-km-long beats: beat 35 (km 16 to 62), beat 3490