Serious road injuries 2016 : estimate of the number of serious road injuries in 2016. In 2016, there were 21,400 serious road injuries. The reliability margin is approximately plus or minus 400. In 2015, there were 21,300 serious road injuries; therefore the number has remained virtually the same. The number of serious road injuries is an important road safety indicator. Since 2010, a serious road injury is defined as follows in the Netherlands: A serious road injury is a road crash casualty who has been admitted to hospital with a minimum injury severity of 2, expressed in MAIS (Maximum Abbreviated Injury Score), and who also did not die of the consequences within 30 days after the crash. No register is available in which all serious road injuries are registered. Since 2008, the number of serious road injuries is therefore determined by comparing the data in two different data sources: BRON (police registration) and LBZ (hospital discharge data). All serious traffic injuries are assumed to be hospitalized. The method to determine the number of serious road injuries consists of four steps: Linking BRON and LBZ and the selection of serious road crash casualties; a correction for incompleteness of LBZ and for crashes that did not take place on a public road; a correction for underreporting in BRON and for misclassifications in LBZ. A calculation of the statistical margin is carried out for this step. A correction for patients who will not be discharged from hospital until 2017 and a scaling of the result on previously established series. The method to estimate the number of serious road injuries in 2016, is the same method that was used in the preceding year. The method is different from that in earlier years (until 2015), especially since the LBZ file may no longer be delivered directly to SWOV (due to privacy legislation). Therefore, the data for the last two years has been sent to Statistics Netherlands (CBS), and pretty much the entire SWOV-research is carried out in the secure remote access environment of Statistics Netherlands. SWOV also needed to find a solution to the information missing in BRON about the hospital name, the injury severity and the modes of transport of casualty and crash opponent. The estimate of the number of serious road injuries has become less accurate after 2009. That has two causes. First the registration of casualties in BRON became less accurate. Second, LBZ also became more incomplete as a result of the introduction of DBC (Diagnosis Treatment Combination) and the new injury coding system ICD10 (International Classification of Diseases, version 10). This year we have been able to perform a margin calculation on the procedure of assessing the number of serious road injuries. Afterwards some minor corrections were made. The basic data itself also contain uncertainties, which contributes to a greater margin on the end result. The margin on the estimated number of serious road injuries is approximately plus or minus 400. The number of casualties with more severe injury (MAIS3+) is slightly higher in 2016 than in 2015 (+ 4%), whereas the number of casualties with less severe injury (MAIS2) is slightly lower in 2016 than in 2015 (-2%). These differences are smaller than the reliability margins and therefore are not significant. As was the case in previous years, in 2016 the group of MAIS3+ casualties constituted about one third of the total number of serious road injuries. We can determine the developments of individual categories of casualties. To do so, we use the patients registered in LBZ with serious traffic injury (MAIS2+). It is uncertain whether the casualties missing from LBZ (5% to 10%) are well represented. This uncertainty implicates that the data of further stratification should be interpreted with caution, see the Road Safety Monitor 2017. The introduction of the registration system KenmerkenmeldingPLUS within the police (in 2013), has led to an increase in the number of correct links between BRON-records and LBZ-records for three consecutive years; in 2016 the number of links is somewhat higher than in 2015. The quality of the links, however, remains insufficient. Certain fields are missing from BRON (hospital name, modes of transport, the distinction between hospitalization and treatment at the emergency room, and other characteristics), while these are necessary for correct linking and calculating the number of serious road injuries. Therefore it is still not possible to perform further stratifications in the number of serious road injuries. This requires further quality improvement of the reporting – and especially the quality of the input. In recent years, the LBZ has also become increasingly complete. In 2016, no clinical admissions are missing any longer. The new ICD-10 coding system has been implemented in all hospitals. Also, the new coding instruction to register external causes of crashes, seems to work well at most hospitals. Since 2015, casualties among motorcyclists are once more registered separately. It is also possible now to distinguish between moped and light moped and between racing bike and pedelec (provided this information is present in the medical record).
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