Psychological Occupational Strain and its Association with Cardiovascular Risk Factors in Bus Drivers

Numerous studies performed in various countries consistently find urban bus driving among the unhealthiest of modern occupations. Urban bus drivers have higher rates of mortality and morbidity compared to other occupational groups, particularly with respect to cardiovascular disease. Psychological occupational strain is also prevalent among bus operators due to the nature of their job conditions, which include high job demands and low control, an imbalance in effort-rewards, and low social support from supervisors. Although extensive literature shows that job strain arising from the work environment is an etiological agent in the poor cardiovascular health and mental health of bus drivers, the relationship between mental health and cardiovascular disease with its risk factors has not been studied in this occupation. This is the first study to investigate whether poor mental health indicators are associated with cardiovascular risk factors in bus drivers, specifically those that make up the American Heart Association (AHA) Life’s Simple 7 predictors of cardiovascular health. In this study, a cross-sectional analysis was performed on self-reported data from 280 bus drivers in Los Angeles County. Psychological strain indicators in the form of mental health, emotional exhaustion, and post-traumatic stress disorder were measured through the General Health Questionnaire (GHQ), Exhaustion Scale of the Maslach Burnout Inventory (ES-MBI), and the Primary Care Post-traumatic Stress Disorder (PC-PTSD) screening questionnaires, respectively. Measures of cardiovascular disease risk was based on data relating to the AHA Life’s Simple 7 (LS7) cardiovascular health metrics, which include blood pressure (BP), cholesterol, diabetes, body mass index (BMI), diet, physical activity, and smoking. The prevalence of bus drivers meeting each LS7 metric criteria was approximately 21% for BP, 11% for cholesterol, 8% for diabetes, 51% for BMI, 21% for physical activity, 9% for diet, 17% for smoking, and 2.5% for inadequate cardiovascular health (CVH) based on overall LS7 score. Statistically significant relationships were found between ES-MBI and BMI, GHQ and BMI, GHQ and BP, GHQ and cholesterol, GHQ and diabetes, and GHQ and inadequate CVH even after controlling for covariates of age, gender, race, education, and socioeconomic status. To investigate whether sex differences exist between associations, stratified analysis by sex was performed. For males, statistically significant relationships between ES-MBI and BMI, GHQ and cholesterol, GHQ and diabetes, and GHQ and inadequate CVH were found even after controlling for covariates combined. For females, statistically significant relationships between GHQ and physical activity and GHQ and BMI were found.This study reveals possible associations with indicators of psychological occupational strain and cardiovascular disease and its risk factors. Further investigation is important to address the limitations of this study and to inform policy and programs that aim to reduce cardiovascular risk in bus drivers by improving their working conditions and promoting their mental health