Association of risky driving behavior with psychiatric disorders among Iranian drivers: A case-control study.

PURPOSE: This study aimed to investigate the possible association between psychological disorders and risky driving behavior (RDB) in Iran. METHODS: This case-control study conducted in Shiraz, Iran in 2021. The case group included drivers with psychological disorders and the control group included those without any disorders. The inclusion criteria for selecting patients were: active driving at the time of the study, being 18 - 65 years old, having a driving license, having a psychological disorder including depression, bipolar disorder, anxiety spectrum disorder, or psychotic disorder spectrum confirmed by a psychiatrist, and completing an informed consent form. The exclusion criterion was the existence of conditions that interfered with answering and understanding the questions. The inclusion criteria for selecting the healthy cases were: active driving at the time of the study, being 18 - 65 years old, having a driving license, lack of any past or present history of psychiatric problems, and completing an informed consent form. The data were gathered using a researcher-made checklist and Manchester driving behavior questionnaire. First, partition around medoids method was used to extract clusters of RDB. Then, backward logistic regression was applied to investigate the association between the independent variables and the clusters of RDB. RESULTS: The sample comprised of 344 (153 with psychological disorder and 191 without confirmed psychological disorder) drivers. Backward elimination logistic regression on total data revealed that share of medical expenditure ≤ 10% of total household expenditure (OR = 3.27, 95% CI: 1.48 - 7.24), psychological disorder (OR = 3.08, 95% CI: 1.67 - 5.70), and substance abuse class (OR = 6.38, 95% CI: 3.55 - 11.48) were associated with high level of RDB. CONCLUSION: Substance abuse, psychological illnesses, and share of medical costs from total household expenditure were found to be main predictors of RDB. Further investigations are necessary to explain the impact of different psychological illnesses on driving behavior.