Estimating the risk of fatal traffic accidents posed by drivers with epilepsy in Japan: A comparison with traffic accidents caused by sudden death of occupational drivers

摘要

Purpose: Proper judgement of the aptitude of people with epilepsy (PWE) for driving is a critical issue, both medically and socially. One thus far reported approach is a quantitative comparison of the risk of fatal traffic accidents caused by PWE drivers and that by subgroups of drivers in the general population. We propose a new approach that compares the risk posed by PWE drivers and that by sudden death of occupational drivers, and the maximum driving time for PWE based on that comparison. Method: The risk of fatal traffic accidents was estimated using four variables. The value assigned to each variable was determined using reports and statistics. Results: The risk of fatal traffic accidents caused by sudden death of occupational drivers was estimated to be 7.6×10-5/year, 4.9×10-5/year, and 1.7×10-5/year for large-sized, mid-sized and normal-sized vehicles. The risk of fatal traffic accidents caused by PWE drivers was estimated to be 5.3×10-5/year and 3.2×10-5/year for PWE with seizure-free periods of 1 year and 2 years, respectively. The maximum acceptable driving time for PWE having a 2-year seizure-free period at the equivalent risk caused by sudden death of occupational drivers of mid-sized vehicles was estimated to be 304 min/week. Conclusion: The risk of fatal traffic accidents caused by PWE drivers can be evaluated by comparing to that caused by sudden death of occupational drivers. Such risk posed by PWE drivers having a 2-year seizure-free period was less than that caused by sudden death of occupational drivers of mid-sized vehicles. Assuming that the society accepts the latter risk, PWE may be permitted to drive for an estimated maximum time at the equivalent risk of causing a fatal accident.