Use of a capture-recapture statistical model to assess morbidity and mortality of road traffic accidents in Gaza Strip: a retrospective study

Abstract

BackgroundIn low-income and middle-income countries, road traffic injuries (RTIs) are commonly under-reported. In this study I estimated the incidence of RTIs and RTI deaths in Gaza Strip using the capture-recapture method. MethodsAll data registered on RTIs and RTI deaths from Jan 1 to Dec 31, 2018, were obtained from police records and Palestinian Ministry of Health hospital records. Linked data from these two sources are available through a web-based registry. When possible, records in the two sets of records were linked by an identification number. I used the Chapman formula of capture-recapture to estimate the numbers of RTIs and RTI deaths: (R=[(R1 + 1)(R2 + 1)/(r+1)]–1). FindingsThe Ministry of Health hospital and the traffic police registries included 1722 and 1356 records, respectively. 970 records could be linked. Although the Ministry of Health hospital records reported more RTIs, fewer than the police records contained information about the injury type and vehicle involved (1053 [61%] vs 1302 [96%] and 849 [49%] vs 1139 [84%], respectively. Most individuals involved in RTIs were men (1313 [76%] in hospital records and 1039 [77%] in police records). 684 (40%) individuals in the hospital records and 516 (38%) in the police records were younger than 15 years and 712 (41%) and 541 (40%), respectively, were in the 15–35-year age group. Most (523 [94%]) of the linked RTIs involved four-wheeled vehicles. The number of RTIs estimated by the Chapman method was 2407 (95% CI 2354–2460), meaning that hospital records captured 72% and police records captured only 56%. The hospital and police records included 16 and 57 deaths, respectively, 14 of which had linked records. Of these deaths, 29 (51%) in the police records and 10 (62%) in the hospital records involved people younger than 15 years, and 45 (79%) and 16 (100%), respectively involved four-wheeled vehicles. The total number of fatalities estimated by the Chapman method was 65 (95% CI 55–74). Therefore, the hospital records captured only 25% whereas police records captured 88%. The population of Gaza Strip in 2018 was 1 932 843 in 2018. Thus, based on the estimated values, the incidence of RTIs would have been 125 per 100 000 population and that for RTI deaths fatalities would have been 3·4 per 100 000 population. InterpretationThe capture re-capture method has some methodological biases, such as it requires an equal probability of capture between data sources, perfect linkage of data from data sources, and closed populations. However, it might be a powerful tool to improve estimates of the incidence of RTIs and RTI deaths where reporting is incomplete. Neither the Ministry of Health hospital nor the police registry independently provided accurate numbers. Both registries should be strengthened to provide reliable information not only on numbers but also on crash circumstances, injury patterns, road users, vehicles involved, and behavioural risk factors. Reporting of injury cause, manifestation, location, severity, and type could be improved by use of a standardised systems, such as ICD-10 codes. FundingNone.