Aim A cohort study was used to follow up the outcomes of DM and treatments to assess for the 6 year risk of RTC event.

Methods Taiwan Bus Driver Cohort Study (TBDCS) recruited 1650 professional drivers in Taiwan since 2005. The subjects were interviewed in person, completed the basic and working patterns questionnaires. Moreover, this cohort of drivers was linked to the National Traffic Accident Database (NTAD), and researchers found 152 new RTC events from 2005 to 2010. History of DM and DM treatments were found from National Health Insurance Research Dataset (NHIRD). Cox proportional hazards model were performed to estimate the hazard ratio (HR) for RTC.

Results The RTC drivers had high frequency of DM (13.8% vs. 7.3%; p=0.007), type 2 DM (13.2% vs. 7.0%; p=0.009), and DM treatment (11.2% vs. 5.8%; p=0.014) in comparison to non-RTC drivers. DM and type 2 DM increased the 6 year RTC risks among professional drivers (HR: 2.31, 95% CI: 1.33 to 4.01; p=0.003, and HR: 2.31, 95% CI: 1.31 to 4.06; p=0.004), even after adjusting for education, caffeine drinks used, sleeping pills used, time since first employment, hypertension, and overnight oxygen desaturation index. Moreover, DM treatment with insulin secretagogue (Sulfonylurea and Meglitinde) and insulin sensitizer (Biguanide) had an increased risk for RTC (HR: 2.22, 95% CI: 1.01 to 4.93; p=0.049, and HR: 2.07, 95% CI: 1.06 to 4.05; p=0.033).

Conclusion This study have proposed recommendations to labour or health care professionals for managing professional drivers with diabetes.