Medical conditions affecting physical capabilities and adverse driving outcomes: an evidence and gap map

Introduction: Some medical conditions may be associated with increased risks of collision and poor performance while driving. Traffic crashes could result in fatalities and injuries. The Australian national medical guidelines do not provide specific instructions for all medical conditions. Clear and high levels of evidence are needed to guide health practitioners’ decision-making processes on medical fitness to drive. Objective: An Evidence and Gap Map (EGM) was conducted to synthesize recent evidence on medical conditions and adverse driving outcomes, which aims to identify available evidence and research priorities. Methods: A search of five academic databases was performed to identify relevant studies; the search involved studies published from June 2009 to February 2022. Cognitive disorders, visual disorders, medication-related conditions, psychiatric conditions, alcohol and drug abuse, and surgical procedures were excluded. The screening was carried out to include eligible studies of physical conditions. A visualized EGM and a descriptive report were produced. Reports included levels of evidence, distribution of evidence about medical conditions, driving outcomes, and geographic locations of included studies. Results: Yielded 16,297 records and 81 eligible primary studies were obtained. Evidence was unevenly distributed by medical conditions, driving outcomes, and geographical locations. Limited studies have been conducted on blackouts, hearing loss and deafness, and musculoskeletal conditions. Neurological conditions were predominant in included studies. The majority of included studies were Level III evidence and Level IV evidence, and the most common study design was observational study. Most included studies were conducted in the Americas and Europe. Major research gaps were recognized in this EGM. One of the main gaps is the lack of evidence of blackouts, hearing loss and deafness, and musculoskeletal disorders. The need for high levels of evidence was identified, particularly the need for prospective cohort studies. Future research priorities were recognized in this EGM.