Reality of traffic injuries attributable to preceding decreased level of consciousness

Although decreased level of consciousness (DLOC) while driving may lead to serious accidents involving drivers and people around them, including passengers and pedestrians, few studies have assessed traffic injuries attributable to preceding DLOC. We aimed to identify factors suggestive of a DLOC preceding traffic injury during initial examination.

This study included 193 drivers who were brought to our facility during the 1-year period from January to December 2018. The drivers were divided into those with and without DLOC for comparison and analysis. Data on age, sex, causes of DLOC, and medical history were retrospectively reviewed from medical records.

Of these 193 drivers, 58 (30.1%) had experienced preceding DLOC. The following factors suggested possible episodes of preceding DLOC: a single-vehicle accident (odds ratio [OR] 3.59; 95% confidence interval [CI] 1.76-7.34; P < 0.001) and histories of hypertension (OR 2.64; 95% CI 1.13-6.15; P = 0.0248) and psychiatric disorders (OR 3.49; 95% CI 1.08-11.3; P = 0.0370). The causes of DLOC were endogenous diseases in 20 drivers (34.3%), dozing off episodes in 19 (32.8%), and acute alcohol intoxication in 11 (19.0%).

Before traffic accidents, 30.1% of drivers experienced DLOC. Single-vehicle accidents and histories of hypertension and psychiatric disorders were factors suggestive of preceding DLOC.