Acute Psychosis and the Risk of Motor Vehicle Crash: Psychose aiguë et risque d’accident de la route

Abstract

Background

Limited evidence guides fitness-to-drive decision-making following an episode of acute psychosis.

Method

We used population-based administrative health and driving data from British Columbia, Canada, to identify all police-attended motor vehicle crashes between 2000 and 2016. Drivers were considered exposed if a hospitalization for acute psychosis ended in the 6-week interval prior to the crash. We assessed the association between psychosis and crashes using a case-crossover design that controls for relatively fixed individual characteristics like personality and routine driving habits. We also conducted a responsibility analysis that accounted for changes in road exposure (kilometres of driving per month) that might occur soon after hospital discharge. Outcomes included involvement in a crash as a driver (for the case-crossover analysis) and driver responsibility for contributing to their crash (for the responsibility analysis). We used logistic regression to evaluate associations between these outcomes and recent hospitalization for acute psychosis, with adjustment for potential confounders.

Results

Among 9,842 crashes in the case-crossover analysis, a hospital stay for acute psychosis ended in 199 pre-crash intervals and in 147 control intervals, suggesting acute psychosis was temporally associated with subsequent crash (2.0% vs. 1.5% of intervals; adjusted odds ratio (aOR), 1.32; 95% CI [1.05–1.66]; P = 0.02). Among 819,348 drivers with a police-attended crash and determinate crash responsibility, 178 of 235 drivers with a recent hospitalization for acute psychosis and 440,543 of 819,113 drivers without recent psychosis were deemed responsible for their crash (75.7% vs. 53.8%; aOR, 2.38; 95% CI [1.75–3.24]; P < 0.001).

Conclusions

The 6-week interval following a hospitalization for acute psychosis is associated with increased odds of crash and increased likelihood of driver responsibility for contributing to their crash. More stringent temporary driving restrictions after an episode of acute psychosis might reduce crash risk.

Plain Language Summary Title

Are drivers at a higher risk of crash after recent hospitalization for acute psychosis?

Plain Language Summary

Acute psychosis can affect how people think and make choices. This can make driving unsafe. But there is little information about when it is safe to drive again after being admitted to the hospital for acute psychosis. In this study, researchers wanted to know if drivers who were recently in the hospital for acute psychosis had more car crashes. To do this, they looked at 20 years of health records and driving data from British Columbia, Canada. The researchers found that crashes happened more often than expected in the first six weeks after leaving the hospital. These drivers were also much more likely to be considered 'responsible' for contributing to their crash than drivers who had not been in the hospital for psychosis. These results show that the time immediately after hospitalization for acute psychosis comes with higher crash risk. Checking if someone is ready to drive and restricting driving for a short period of time after acute psychosis may help reduce crashes and keep roads safer.