Improperly Recorded Pedestrian Injuries

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My friend Morten and I are doing a study to see if increased cycle helmet-wearing among children in Sweden has affected head injuries. As a comparison, we are also looking at head and other injuries among other road users aged 0-15. Our data come from the patient register at the Swedish National Board of Health and Welfare (Socialstyrelsens patientregister). The data is classified according to ICD-10 (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision).

Malcolm Wardlaw generously helped us in navigating the ICD-10 codes, especially regarding pedestrian injuries, which may happen in collisions with vehicles or as simple falls in different places. In ICD-10, hospitals assign one of ten place codes to pedestrian falls according to where they occur. Our data includes pedestrian falls occuring in streets or roads (place code .4), parking lots, parks or forests (place code .8), as well as falls occuring in unspecified places (place code .9).

As shown in the graph, a large majority of the injuries in our data are pedestrian falls in unspecified places. This raises the question if some of these falls actually occured in streets, roads, parking lots or other places pedestrians might find themselves when walking to school, work or other everyday destinations.

There is a perception that, for all age groups, cyclists are the road user group with the largest number of injuries. If the 16-and-over age group has a similarly large number of uncategorised pedestrian falls, it is possible that this perception is untrue.

Official Swedish road crash data are published in another system called STRADA (Swedish Traffic Accident Data Acquisition). One of the data sources for STRADA is the patient register. If the patient register is inaccurate, STRADA will also be inaccurate.

Dalacyklister näst bäst på hjälm. SVT
Statistiken visar att cyklister i dag är den mest utsatta trafikantgruppen. Varje år skadas mer än 2 500 cyklister så svårt att de måste tillbringa minst ett dygn på sjukhus.