BACKGROUND: Several studies have shown that professional drivers are at risk of developing work-related stress. Stress may be responsible for a variety of adverse effects and may also be associated with an increased number of accidents.
OBJECTIVE: Perform an integrated, objective and subjective evaluation of work-related stress in bus drivers, that also considered the role of personality traits.
METHODS: Salivary α-amylase and cortisol were measured in 42 bus drivers. Subjective stress evaluation was performed with the Perceived Stress Scale (PSS-10) and Driver Stress Inventory (DSI). To evaluate personality traits, we administered the Eysenck Personality Questionnaire-Revised (EPQ-R) and the Impulsivity Inventory (IVE).
RESULTS: Salivary biomarkers showed no associations with PSS-10 and personality traits. Cortisol levels were positively correlated with fatigue (r = 0.44) at the middle of the work-shift and with aggression (r = 0.51) at the end of a day off. At the end of the work-shift, cortisol levels were negatively correlated with hazard monitoring (r = -0.37) and salivary α-amylase was positively correlated with thrill-seeking (r = 0.36). Neuroticism (β= 0.44) and impulsiveness (β= 0.38) were predictors of perceived stress by multiple regression.
CONCLUSIONS: An integrated method, considering both objective and subjective indicators, seems adequate to evaluate work-related stress in professional drivers. Personality traits are relevant in determining perception of stress.