Risk factors for unintentional occupational injury among urban transit bus drivers: a cohort longitudinal study

Purpose Although many studies have focused on bus operators' occupational diseases, work-related injury and associated risk factor data are limited. The purpose of this longitudinal study was to investigate unintentional injury and exposures that may affect injury risk among metropolitan bus operators. Methods Demographic, work-related, and injury data obtained from a metropolitan transit company for a 5-year period, enabled estimates of rates per 100 full time equivalents (FTEs) and adjusted Hazard Ratios (HRs), with 95% confidence intervals (CIs), using Generalized Estimating Equations and Cox proportional hazards models, respectively. Results The 2095 bus operators, included in this study, had an unintentional injury rate (95% CI) of 17.8 (16.1–19.7) per 100 FTEs. Multivariable analysis identified increased risks for operators who were female, compared to male (HR = 2.4; 2.0–2.8); worked less than 7 versus 7 to less than 12 hours per day (HR = 4.6; 3.8–5.5); and drove less than 7 versus 7 to less than 12 hours per day (HR = 3.2; 2.7–3.8). Suggestive increased risks were identified for operators working split versus straight shifts (HR = 1.2; 1.0–1.4) and for driving limited versus regular bus routes (HR = 1.36; 1.0–1.8). Conclusions Results serve as a basis for further studies and inform the development of targeted intervention strategies to reduce bus operators' occupational injuries.