1. Introduction

Traffic accidents are a worldwide public health issue ^[1]. This assumption becomes relevant considering that traffic crashes cause high number of deaths and injuries every year, affecting different sectors of the population, especially the people who is more frequently exposed to the road environment ^[2]. In this sense, there is a growing number of occupational groups classified as at high psychosocial risk, such as professional drivers. Among them, public transport drivers tend present several occupational and extra-occupational risks such as work stress, burnout and traffic accidents ^{[3, 4, 5, 6]}.

Numerous epidemiological studies associates work stress with psychosocial risk, morbidity and mortality ^{[7, 8, 9]}. Furthermore, the recent scientific evidences in the particular context of bus drivers associates psychosocial work factors with adverse health and organizational outcomes, such as burnout, poor physical and mental health, counterproductive work behaviors, increased risk for accidents and poor job performance [10-15]^[10].

Work stress Models and professional driving

Work stress is one of the factors more frequently associated with accidents and occupational injuries ^{[9] [13]}. The Effort-Reward Imbalance model (ERI) ^[16] associates work stress with a problematic disequilibrium between the efforts performed to accomplish work tasks and the rewards (salary, esteem and promotion) received as retribution. Moreover, the ERI model states that high levels of over-commitment (a motivational pattern that imply inability to detach from work) increase the risk of poor health outcomes ^[17]. Moreover, On the other hand, the Job Demand-Control model (JDC) states that work stress is generated by the combination (known as job strain) of high psychological demands and low job control (skill discretion and decision authority) ^{[18, 19]}. Additionally, the JDC model suggest that the negative outcomes associated with job strain are stronger in situations of low social support and job insecurity. There are abundant research on the association between the ERI-JDC models and negative health and job performance outcomes, including some studies on Bus drivers ^{[20, 21, 22]}. In this occupational group, low control, work overtime, irregular working schedules, shift work, emotional labor, low decision capacity and the lack of social support and low have been identified as highly prevalent stressors ^{[23, 24]}. Furthermore, it is known that bus drivers are in high risk for work stress related diseases such as hypertension ^{[25, 26, 27, 28, 29]}, metabolic syndrome and ergonomic problems ^{[5, 30]}, and health risk behaviors such as smoking and drinking ^{[31, 32]}.

Burnout and professional driving

Burnout is a psychological syndrome, which raises in response to the chronic exposure to work-related stressors ^{[33, 34, 35]}. Burnout is composed by three components: emotional exhaustion or the feeling of emotional overwhelming at work; cynicism (also known as disengagement or depersonalization), defined as the detachment from others or indifference at work; and professional efficacy (also named professional accomplishment), which is the tendency to evaluate one’s efforts and achievements in a negative way ^{[36, 37]}.

Burnout has been widely related to different negative health outcomes, such as anxiety ^[38], depression ^{[38] [39]}, sleep disturbances ^{[40, 41, 42]}, headaches ^[43], gastrointestinal disease ^[44], hypertension ^[45], muscle tension ^[34], chronic fatigue ^[37], and especially in the case of professional drivers, with poor job performance ^{[46, 47]}. In the organizational field, burnout has been also associated with absenteeism and high turnover intention ^{[48, 49]}. Intervention studies have shown that the continuous task evaluation and improvement ^{[50, 51, 52, 53]}, and the socio-emotional support from co-workers and members of micro-social environment (such as family members and friends) are relevant factors in the management and prevention of burnout.

Professional drivers’ health and road safety

Previous research suggest that professional drivers are at higher risk occupational illness, in comparison with other occupational groups ^[54]. Recent studies have found that professional drivers’ health problems are associated with sickness absence, turnover intention and accidents ^{[3, 55]}. Research on bus drivers also report that fatigue ^[56], shift work ^{[46, 57]}, age, driving experience, previous accidents and their severity, the type of vehicle (urban/city bus, taxi, BRT bus) and route are correlated with the risk of being involved in road accidents ^{[58, 59]}.

In other words, a professional driver who experiences health problems (e.g. cardiovascular and musculoskeletal diseases, obesity, mental problems), may have up to twice the risk of have traffic crashes ^{[60, 61]}. Health problems also increase the effect of subjective variables (e.g. age, experience, burnout, stress) on risky driving behaviors (both driving errors and traffic violations) ^{[62, 63]}. This increased risk for road accidents compromises the health and safety of both professional drivers and other users of the road, such as their passengers, pedestrians and other drivers who share the road with public transport vehicles ^[8].

The cumulative scientific evidence collected over the past five decades suggests that, comparing professional drivers with workers belonging to other occupational groups, the first tend to report a higher prevalence of different illnesses or diseases, such as cardiovascular ^[64], musculoskeletal ^[54] and gastrointestinal problems ^[35]. Regarding mental health issues, it has been concluded that different psychological disorders such as depression, anxiety, and post-traumatic stress disorders are highly prevalent among active professional drivers, and constitute risk factors for suffering occupational-related accidents ^{[6, 8, 64, 65]}.

Risky behaviors, traffic accidents and public health

In the context of professional driving, road crashes are unplanned events, which causes material damages or injuries. The potential health damage to the road users makes traffic accidents a public health issue ^{[2, 66]}. Age and experience are documented predictors of the risk of road crash ^{[3, 59, 67, 68]}. However, little research had investigated the association between psychosocial risk at work and driving performance ^[69].

One of the factors most commonly employed to predict traffic accidents are risk behaviors. Unsafe driving behavior has been associated with work-related stress, especially in the case of Bus operators and other groups of public transport drivers. For instance, Kontogiannis found that risk behaviors on the road predict traffic accidents on professional drivers ^{[14, 68]}. Therefore, variables such as work stressors ^{[67, 70, 71]}, cognitive overstimulation ^[64], weather, road conditions ^{[70, 72]}, driving performance ^{[59, 73]} and prolonged interaction with other road users ^{[74, 75]} are relevant factors in the management of safety issues in the transport industry ^[6].

Regarding accident prevention in professional drivers, some previous experiences suggest that healthy employees working under optimal conditions have a less probability to suffer road crashes ^[3]. Furthermore, several programs designed for stress prevention at work have shown to be useful for both the employee and transport companies, taking into account the potential accident cost savings and the substantial reduction in terms of psychosocial and health risks for operators and passengers ^{[3, 76]}.

Research in job strain, effort-reward imbalance and burnout among professional drivers have been increasing along the last two decades ^{[77, 78]}. Taking into account the association between the performance of public transport drivers and the safety of all road users, the occupational stressors in this occupational group gain importance. It is known the physical and psychological health of Bus drivers play a determinant role on their driving performance ^{[79, 80]}. Any impairment in the bus drivers’ performance can generate undesirable consequences for passengers and transport operating companies in form of negative health and economical outcomes ^{[59, 81]}.

Bus transportation is one of the most used modes of public transport worldwide. Therefore, the need to address the psychosocial work environment of bus drivers for improvement should be a priority. However, there are differences between the working conditions of public transport drivers that should be considered for the prevention of accidents and promotion of road safety. This study focuses on the differences between the working conditions of Urban (or City) Bus drivers and BRT operators. According with Deng & Nelson ^[82], Bus Rapid Transit (BRT) is a system characterized by modern vehicles, dedicated or semi exclusive bus lanes and applications of ITS (Intelligent Transportation Systems) technologies to the monitoring and improving of service. This mode of public transport has been growing worldwide, thanks to its cost–benefit efficiency ^{[56, 69]}. BRT systems have been implemented in Bogota, Colombia since 2000 ^[82] as an alternative to the traditional Urban Bus system. The Bogotá case is interesting, because the implementation of BRT systems considerably reduced the vehicular congestion, gas emissions and travel times of the citizens. ^{[69, 82]}. However, different problems related to the BRT operation have been documented, such as excessive passenger demand, road deterioration and work-overload for its operators ^[82].

The aim of this study was to compare job stress, burnout, health outcomes and traffic accidents between Urban/City Bus drivers and BRT drivers. Moreover, some guidelines useful for preventing negative occupational outcomes and reducing accidents in the transportation industry are proposed.

2. Methods and Materials

The study sample was composed by 361 Colombian bus drivers (n=222 Urban Bus drivers ^[83] and n=139 BRT operators ^[5]) between 20-79 years of age, with a mean of X=41.46 (SD=9.68) years. The average driving experience of these bus operators was X=17.5 (SD=9.836) years. On average, this sample of professional drivers had X=7.20 (SD=6.41) years working in their current transport company.

Women were excluded due to their very low representation in the bus drivers’ occupational group. The number of participants represents an error margin for the general data of ±2.75 with a 95% confidence interval in the most unfavorable case of p=q=50%.

The participants completed a questionnaire in paper version, at the facilities of the transport companies that agreed to participate in the study. The survey was conducted guaranteeing the anonymity of the participants, and emphasizing on the fact that the data would only be used for research purposes. It was used an informed consent statement, signed by both parties before the participants answered the questionnaire. The final response rate was superior than 95%.

The questionnaire was administrated in Spanish language, and consisted of four sections. In the first section, demographic variables (age, driving experience) and road incidents (accidents + traffic tickets or “fines” in the last two years) were collected.

The second section of the questionnaire collected information about the ERI and JDC models. The JDC model was measured using the Job Content Questionnaire (JCQ), validated by Gómez for Colombian workers ^[84]. The JCQ has been widely used to assess psychosocial factors in the workplace and their effects on health. It’s response scale consists of a 4-point Likert scale (1= “totally disagree” and 4= “totally agree”). The 27 items (full scale) of the JCQ are grouped in six sub-scales: support from supervisors (4 items, α=0.87), peer support (4 items, α=0.79), skill discretion (6 items, α=0.75), decision authority (3 items, α=0.69), psychological demands (6 items, α=0.66), and job insecurity (4 items, α=0.53). Decision latitude was calculated as de sum of skills discretion and decision-making. Social support was calculated as the sum of support from supervisors and peer support. And Job strain was computed as the ratio between psychological demands and decision latitude (demands/ decision latitude). The ERI model was measured using the 23-item version of the Effort-Reward Inventory ^{[85, 86]}. This questionnaire consist of three sub scales: extrinsic effort (6-item, α=0.73; α=0.74), rewards (11-item, alpha α=0.77; α=0.79 original) and over-commitment (6-item; α=0.78). This version of the ERI questionnaire was previously been validated in Colombia by Gómez ^[87].

The third section the Spanish version of the Maslachs’ Burnout Inventory (MBI) ^{[88, 89]} was administrated. This questionnaire consists of 16 questions [0-6 scale] grouped in three subscales: emotional exhaustion (5 items, α=0.88), depersonalization/cynicism (5 items, α=0.67), and professional efficacy (6 items, α=0.78) ^[90].

Finally, the fourth section consisted of questions about height and weight (with the aim to build BMI in an objective manner), and self-reported physical health: Do you smoke (Yes/No)? Do you have a sedentary lifestyle (Yes/No)? Do you suffer a) diabetes, and b) hypertension?

First, descriptive statistics and Pearson’ (bivariate) correlational analysis were performed. An analysis of Variance (ANOVA) was conducted in order to compare the work conditions and health outcomes of Urban Bus drivers and BRT operators. All statistical analyses were performed using ©IBM SPSS (Statistical Package for Social Sciences), version 23.0.

3. Results

Table 1 presents the descriptive statistics of the study variables (full sample) and the Pearson correlations between them. The full sample had an average of job strain slightly below the risk score (greater value than 1 are indicator of unfavorable imbalance between demands and control). On the other hand, the ERI score was relatively high. The average levels of the MBI (i.e. exhaustion and cynicism) were relatively high, except for average of professional efficacy. Job strain was positively associated with emotional exhaustion at work and cynicism, and negatively with professional efficacy and accidents. The ERI score correlated positively with emotional exhaustion, and negatively with professional efficacy.

Table 1. Descriptive statistics and Pearson correlations between the study variables (full sample)

Download as

PowerPoint Slide

Larger image(png format)

• Tables index

Veiw figure

View current table in a new window

View next table

Table 2. Descriptive data and mean differences between the two groups of drivers

Download as

PowerPoint Slide

Larger image(png format)

• Tables index

Veiw figure

View current table in a new window

View previous table

View next table

Although both groups of drivers report a similar mean of age, there are statistically significant differences in the BMI (F_(1,333)=12.414; p<0.01) and the number of traffic accidents suffered in the last two years (F_(1,351)=7.629; p<0.01). In particular, City Bus drivers have a higher average body mass index and have suffered significantly more road accidents in the last two years than the BRT drivers.

Comparisons between the two groups of professional drivers have shown that Urban Bus drivers have, in average, more control at work than the BRT drivers (F_(1,347)=33.560; p<0.01), but also more psychological demands (F_(1,352)=142.416; p<0.01). Regarding job strain (job stress indicator of the model), the mean scores are significantly higher for City Bus drivers (F_(1,346)=13.938; p<0.01). BRT drivers also perceive less job insecurity than Urban Bus drivers (F_(1,352)=37.571; p<0.01). Finally, no significant differences were found for perceived social support.

Urban/City Bus drivers have shown significantly higher scores regarding perceived efforts realized to accomplish work labors (F_(1,344)=68.249; p<0.01), but also, a higher rate of rewards (F_(1,345)=54.268; p<0.01). In the case of over-commitment, the mean score is higher for Urban Bus drivers than for BRT operators (F_(1,346)=124.584; p<0.01). However, no significant differences were found in terms of Effort-Reward Imbalance (job stress indicator of ERI model).

The Analysis of variance show significant differences in the scores of emotional exhaustion (F_(1,350)=20.868; p<0.01), cynicism (F_(1,345)=7.357; p<0.01), and being the average scores higher for Urban Bus drivers. Meanwhile, the average of professional efficacy (or “accomplishment”) was higher for BRT drivers (F_(1,347)=196.383; p<0.01). In other words, Urban Bus drivers shows more burnout than BRT drivers do.

The prevalence of adverse health behaviors, such as smoking and sedentary lifestyle, is higher (in both cases) for Urban Bus drivers (see Table 3). Furthermore, the prevalence of overweight (Body Mass Index >25) is higher for Urban Bus (67.9%) than for BRT drivers (50.8%). However, in both groups the prevalence of overweight was very high.

Specifically 32.1% of Urban Bus drivers and 48.3% of BRT operators have a BMI between 19 and 25 (“ideal weight”). Meanwhile, 52.1% of Urban Bus drivers and 42,8% f BRT operators are located in the “overweight” category. Further, 15.8% of Urban Bus and 5.0% of BRT drivers suffer obesity (see Figure 1).

Table 3. Frequency of registered prevalence of lifestyle factors and health complains

Download as

PowerPoint Slide

Larger image(png format)

• Tables index

Veiw figure

View current table in a new window

View previous table

Download as

• PPT
  PowerPoint Slide
• PNG
  Larger image(png format)

Veiw figureFigures index

•  NEW
  View larger figure in new window

Figure 1. Body Mass-level distribution according to the group of drivers

Regarding self-reported illnesses, it was found that 2.8% of Urban Bus drivers and 0.8% of BRT drivers have been diagnosed with diabetes. Also, 7.9% (Urban Bus) and 5.3% (BRT) suffer hypertension.

4. Discussion

This research was aimed to compare the work-related stressors, health outcomes and accidents of Urban Bus and BRT drivers. As main descriptive result, it was found that Urban Bus drivers present higher stress, burnout and health problems than their BRT counterparts. In general, the existing literature locates public transport drivers as one of the groups with higher psychosocial risk at work ^{[3, 4]}. Furthermore, the growing evidence on the association between work stress, burnout and negative organizational outcomes (especially accidents) among professional drivers highlights the relevance of studying and intervening on this issues ^{[10, 45]}.

With regard to the relationship between the ERI model and road crashes or penalties, some studies have found a positive association between the effort-reward imbalance and road incidents among professional drivers, not all of them in the field of public transportation, but keeping close similarities regarding work schedules and stress measures. Although some empirical applications have reported not significant associations between work stress and driving performance in Urban Bus drivers ^[61], other researchers have found indirect effects of work stress on road accidents through mediators such as fatigue ^{[56, 61, 83, 84, 85]} and health problems ^{[5, 19]}. This study suggests that, in combination with burnout, job strain is a significant risk factor for road accidents among bus drivers.

Referring to the prevention of occupational traffic crashes, intervention strategies to manage work stress and burnout may generate positive outcomes for worker’s health, safety and welfare, especially in the mid and long term ^{[8, 69]}. The findings of this study suggest that there are substantial differences between the work conditions of BRT and Urban bus drivers. Although the stressors and burnout of BRT drivers are relatively high, the core characteristics of the BRT systems (exclusive lanes for the transit of the buses, elevated platforms to pick-up passengers and highly controlled itinerates) apparently contribute to enhance driving performance and reduce work stressors ^[82]. However, the BRT transportation system still present stressing conditions, especially time pressure and lack of job control, which are less prevalent in other public transportation systems ^[69].

Furthermore, BRT systems remain vulnerable to external risk factors such high amount of passengers, passenger aggression and adverse road conditions ^{[66, 71]}. These external factors, combined to subjective problems of stress, burnout, may contribute to increase the risk of occupational accidents and poor health ^{[9, 79, 80]}.

Finally, it is important to highlight the high prevalence of overweight and sedentary behavior in both BRT and Urban bus drivers ^{[91, 92]}. Obesity and low physical activity are leading factors for cardiovascular disease, which in turn is associated with road accidents ^{[93, 94]}. Moreover, work stress is associated with overweight ^{[95, 96]} and negative lifestyle ^{[97, 98]} and health outcomes ^{[99, 100]}. In this sense, intervention programs addressing the occupational and health risks of bus drivers are urgently needed ^{[101, 102]}.

5. Conclusion

This study showed that the prevalence of work-related stress and burnout are elevated among Colombian bus drivers. In addition, it was found that the bus drivers’ work stress is associated to burnout. Comparatively, BRT drivers tend to present better health and organizational outcomes than Urban Bus operators. However, both groups show relatively high risk for work stress, burnout and road accidents. Therefore, the intervention on these factors represent a potentially successful alternative for the prevention of occupational traffic accidents and negative health outcomes that represent very high costs for transport companies and the health systems.

Although the questionnaires used in this research have good reliability, remain vulnerable to self-report bias. The sampling strategy of the study limits the generalizability of the findings. Finally, the cross sectional design did not allow inferring causality from the association between work stress, burnout, health issues and road accidents.

References

[1]	World Health Organization (WHO). 2013. “Global status report on road safety 2013: supporting a decade of action”. Available at: https://www.who.int/violence_injury_prevention/road_safety_status/2013/en/[Access date: 23.11.2016].
	In article
[2]	World Health Organization (WHO). 2009. “Global status report on road safety: Time for action”. https://apps.who.int/iris/bitstream/10665/44122/1/9789241563840_eng.pdf [Access date: 21.11.2016].
	In article
[3]	Albright, C., Ingleby, M., Ragland, D., Fisher, J. and Leonard, S. “Job strain and prevalence of hypertension in a biracial population of urban bus drivers. American Journal of Public Health, 82(7): 984-989. 1992.
	In article
[4]	Tse, J., Flin, R. and Mearns, K. “Facets of job effort in autobus driver health: deconstructing “effort” in the effort–reward imbalance model”. Journal of Occupational Health Psychology, 12(1): 48-62. 2007.
	In article
[5]	Cendales, B., Useche, S.A. and Gómez V. “Psychosocial Work Factors, Blood Pressure and Psychological Strain in Male Bus Operators”. Industrial Health, 52: 279-288. 2014.
	In article
[6]	Tse, J., Flin, R. and Mearns, K. “Bus driver well-being review: 50 years of research”. The Industrial Psychology Research Centre. Transportation Research. 9: 89-114. 2005.
	In article
[7]	Carrere, S., Evans, G., Palsane, M. and Rivas, M. “Job Strain and Occupational Stress Among Urban Public Transit Operators”. Journal of Occupational Psychology, 64: 305-316. 1991.
	In article
[8]	Taylor, A. and Dorn, L. “Stress, fatigue, health, and risk of road traffic accidents among professional drivers: The contribution of physical inactivity”. Public Health, 27: 371-391. 2006.
	In article
[9]	Aronsson, G. and Rissler, A. “Psychophysiological stress reactions in female and male urban bus drivers”. Journal of Occupational Health Psychology, 3(2): 122-129. 1998.
	In article
[10]	Iacovides, A., Fountoulakis, K.N., Kaprinis, S. and Kaprinis, G. “The relationship between job stress, burnout and clinical depression”. Journal of Affective Disorders, 75: 209-221. 2003.
	In article
[11]	Sarsangi, V., Motallebi, M., Khodadadi, R., Shajari, M., Keyvani, S. and Yousefzadeh, M. “Correlation between Occupational Stress and Burnout in Rehabilitation Center Employees of Kashan, Iran”. Quarterly of International Archives of Health Sciences, 2(1): 13-18. 2015.
	In article
[12]	Maslach, C. “Burnout: A multidimensional perspective”. In: Schaufeli, B., Maslach, C., Marek, T. (eds.). “Professional Burnout: Recent developments in theory and research”. Taylor & Francis, Washington, 1993, 19-32.
	In article
[13]	Cooper, D. “Human factors in accidents”. Institute of Quarring, North of England. Ramside Hall, Durham, 2002.
	In article
[14]	Kontogiannis, T. “Patterns of driver stress and coping strategies in a Greek sample and their relationship to aberrant behaviors and traffic accidents”. Accident Analysis & Prevention, 38(5): 913-24. 2006.
	In article
[15]	Machin, M. and De Souza, J. “Predicting health outcomes and safety behavior in taxi drivers”. Transportation Research, 7(1): 257-270. 2004.
	In article
[16]	Siegrist, J. “Effort-reward imbalance at work and health”. In: Ganster, D., Perrewe, P. (eds.). “Historical and current perspectives on stress and health”, Vol. 2. Elsevier Science Ltd., Amsterdam, 2002, 261-291.
	In article
[17]	Siegrist, J. “Effort-reward imbalance at work - theory, measurement and evidence”. Dusseldorf University, Dusseldorf, 2012.
	In article
[18]	Karasek, R. “Demand/Control model: A social, emotional, and physiological approach to stress risk and active behavior development”. ILO Encyclopedia of Occupational Health and Safety, 4th ed. Princeton, Geneva, 1998.
	In article
[19]	De Lange, A.H., Kompier, M.A., Taris, T.W., Geurts, S.A., Beckers, D.G., Houtman, I.L., et al. “A hard day's night: a longitudinal study on the relationships among job demands and job control, sleep quality and fatigue”. Journal of Sleep Research, 18(3): 374-383. 2009.
	In article
[20]	Ardito, C., d’Errico, A. and Leombruni, R. “Exposure to psychosocial factors at work and mental well-being in Europe”. La Medicina del Lavoro, 105(2): 85-99. 2014.
	In article
[21]	Ahola, K., Gould, R., Virtanen, M., Honkonen, T., Aromaa, A. and Lönnqvist, J. “Occupational burnout as a predictor of disability pension: A population-based cohort study”. Occupational and Environmental Medicine, 66(5): 284-290. 2009.
	In article
[22]	Tsai, S.S., Lai, C.H., Shih, T.S., Lin, M.H. and Liou, S.H. “High job strain is associated with inflammatory markers of disease in young long-haul bus drivers”. Journal of Occupational Health Psychology, 19(3): 336. 2014.
	In article
[23]	Oramas, A., González, A. and Vergara, A. “El desgaste profesional: evaluación y factorialización del MBI-GS”. Revista Cubana de Salud y Trabajo, 8(1): 37-45. 2007.
	In article
[24]	Van Vegchel, N., de Jonge, J., Bosma, H. and Schaufeli, W. “Reviewing the effort-reward imbalance model: drawing up the balance of 45 empirical studies”. Social Science & Medicine, 60(5): 1117-1131. 2005.
	In article
[25]	Habibi, E., Poorabdian, S. and Shakerian, M. “Job strain (demands and control model) as a predictor of cardiovascular risk factors among petrochemical personnel”. Journal of Education and Health Promotion, 4: 16. 2015.
	In article
[26]	Magnavita, N. “Two tools for health surveillance of job stress: The Karasek Job Content Questionnaire and the Siegrist Effort Reward Imbalance Questionnaire. Giornale Italiano di Medicina del Lavoro ed Ergonomia, 29(3 Suppl): 667-670. 2007.
	In article
[27]	Theorell, T. and Karasek, R. “Current issues relating to psychosocial job strain and cardiovascular disease research”. Journal of Occupational Health Psychology, 1(1):9-26. 1996.
	In article
[28]	Gilbert-Ouimet, M., Trudel, X., Brisson, C., Milot, A. and Vézina, M. “Adverse effects of psychosocial work factors on blood pressure: systematic review of studies on demand-control-support and effort-reward imbalance models”. Scandinavian Journal of Work, Environment & Health, 40(2): 109-132. 2014.
	In article
[29]	Gilbert-Ouimet, M., Brisson, C., Vézina, M., Milot, A. and Blanchette, C. “Repeated exposure to effort-reward imbalance, increased blood pressure, and hypertension incidence among white-collar workers: effort-reward imbalance and blood pressure”. Journal of Psychosomatic Research, 72(1): 26-32. 2012.
	In article
[30]	Koch, P., Schablon, A., Latza, U. and Nienhaus, A. “Musculoskeletal pain and effort-reward imbalance- a systematic review”. BMC Public Health, 14:37. 2014.
	In article
[31]	De Jonge, J., Bosma, H., Peter, R. and Siegrist, J. “Job strain, effort-reward imbalance and employee well-being: a large-scale cross-sectional study”. Social Science & Medicine, 50(9): 1317-1127. 2000.
	In article
[32]	Chung, Y.S. and Wu, H.L. “Stress, strain, and health outcomes of occupational drivers: An application of the effort reward imbalance model on Taiwanese public transport drivers”. Transportation Research Part F: Traffic Psychology and Behaviour, 19: 97-107. 2013.
	In article
[33]	Couto, M.T. and Lawoko, S. “Burnout, workplace violence and social support among drivers and conductors in the road passenger transport sector in Maputo City, Mozambique”. Journal of Occupational Health, 53(3): 214-21. 2011.
	In article
[34]	Khamisa, N., Oldenburg, B., Peltzer, K. and Ilic, D. “Work Related Stress, Burnout, Job Satisfaction and General Health of Nurses”. International Journal of Environmental Research and Public Health, 12(1): 652-666. 2015.
	In article
[35]	Maslach, C. “Comprendiendo el Burnout”. Ciencia y Trabajo, 11(32): 37-43. 2009.
	In article
[36]	Taris, T.W., Schreurs, P.J.G. and Schaufeli, W.B. “Construct validity of the Maslach Burnout Inventory – General Survey: A two-sample examination on its factor structure and correlates”. Work & Stress, 13(3): 223-237. 1999.
	In article
[37]	Pereira-Lima, K. and Loureiro, S.R. “Burnout, anxiety, depression, and social skills in medical residents”. Psychology, Health & Medicine, 20(3): 353-362. 2015.
	In article
[38]	Schonfeld, I.S. and Bianchi, R. “Burnout and Depression: Two Entities or One?”. Journal of Clinical Psychology, 72(1): 22-37. 2016.
	In article
[39]	Pagnin, D., De Queiroz, V., Carvalho, Y.T., Dutra, A.S., Amaral, M.B. and Queiroz, T.T. “The relation between burnout and sleep disorders in medical students”. Academic Psychiatry, 38(4): 438-444. 2014.
	In article
[40]	Shad, R., Thawani, R. and Goel, A. “Burnout and Sleep Quality: A Cross-Sectional Questionnaire-Based Study of Medical and Non-Medical Students in India”. Cureus, 7(10): e361. 2015.
	In article
[41]	Philip, P., Sagasge, P., Moore, N., Taillard, J. and Horne, J.A. “Fatigue, sleep restriction and driving performance”. Accident Analysis & Prevention, 37, pp.473-478. 2005.
	In article
[42]	Khamisa, N., Peltzer, K. and Oldenburg, B. “Burnout in Relation to Specific Contributing Factors and Health Outcomes among Nurses: A Systematic Review”. International Journal of Environmental Research and Public Health, 10(6): 2214-2240. 2013.
	In article
[43]	Huerta-Franco, M.R., Vargas-Luna, M., Tienda, P., Delgadillo-Holtfort, I., Balleza-Ordaz, M. and Flores-Hernandez, C. “Effects of occupational stress on the gastrointestinal tract”. World Journal of Gastrointestinal Pathophysiology, 4(4): 108-118. 2013.
	In article
[44]	Komissarova, E.M. and Ermakova, M.A. “Characteristics of arterial hypertension in psychoemotional burnout of emergency medical staffers”. Meditsina Truda I Promyshlennaia Ekologiia, 10: 19-23. 2011.
	In article
[45]	Huibers, M., Beurskens, A., Prins, J., Kant, I., Bazelmans, E., van Schayck, C.P., Knottnerus, J. and Bleijenberg, G. “Fatigue, burnout, and chronic fatigue syndrome among employees on sick leave: do attributions make the difference?”. Occupational Environmental Medicine, 60(1): i26-i31. 2003.
	In article
[46]	Kee, S., Mohd, S.B. and Goh, Y.M. “Driving Fatigue and Performance among Occupational Drivers in Simulated Prolonged Driving”. Global Journal of Health Science, 2(1): 167-177. 2010.
	In article
[47]	Demerouti, E., Bakker, A.B. and Leiter, M. “Burnout and job performance: the moderating role of selection, optimization, and compensation strategies”. Journal of Occupational Health Psychology, 19(1): 96-107. 2014.
	In article
[48]	Ahola, K., Toppinen-Tanner, S., Huuhtanen, P.A., Koskinen, A. and Väänänen, A. “Occupational burnout and chronic work disability: An eight-year cohort study on pensioning among Finnish forest industry workers”. Journal of Affective Disorders, 115(1-2): 150-159. 2009.
	In article
[49]	Garrosa-Hernández, E., Moreno-Jiménez, B., Liang, Y. and González-Gutiérrez, J.L. “The relationship between sociodemographic variables, job stressors, burnout, and hardy personality in nurses: an exploratory study”. International Journal of Nursing Studies, 45(3): 418-427. 2008.
	In article
[50]	Awa, W.L., Plaumann, M. and Walter, U. “Burnout prevention: a review of intervention programs”. Patient Education and Counseling, 78(2): 2010. 184-90.
	In article
[51]	Lepore, S.J., Allen, K.A. and Evans, G.W. “Social support lowers cardiovascular reactivity to an acute stressor”. Psychosomatic Medicine, 55, 518-524. 1993.
	In article
[52]	Ozbay, F., Johnson, D.C., Dimoulas, E., Morgan, C.A, Charney, D. and Southwick, S. “Social Support and Resilience to Stress: From Neurobiology to Clinical Practice”. Psychiatry (Edgmont), 4(5): 35-40. 2007.
	In article
[53]	Quick, J.C., Quick, J.D., Nelson, D.L. and Hurrell, J.J. “Preventive stress management in organizations”. American Psychological Association, Washington DC, 1997. p. 277-300.
	In article
[54]	Honkonen, T., Ahola, K., Pertovaara, M., Isometsä, E., Kalimo, R., Nykyri, E., Aromaa, A. and Lönnqvist, J. “The association between burnout and physical illness in the general population--results from the Finnish Health 2000 Study”. Journal of Psychosomatic Research, 61(1): 59-66. 2006.
	In article
[55]	Winkleby, M.A., Ragland, D.R., Fisher, J.M. and Syme, S.L. “Excess risk of sickness and disease in bus drivers: a review and synthesis of epidemiological studies”. International Journal of Epidemiology, 17(2): 255-62. 1988.
	In article
[56]	Useche, S., Cendales, B. and Gómez, V. “Measuring Fatigue and its Associations with Job Stress, Health and Traffic Accidents in Professional Drivers: The Case of BRT Operators”. EC Neurology, 4(4): 103-118. 2017.
	In article
[57]	Hervas, A., Tortosa, F., Ferrero, J. and Civera, C. “Effects of fatigue on simulated high speed driving for prolonged periods”. Universitas Psychologica, 10(3): 897-907. 2011.
	In article
[58]	Gopalakrishnan, S. “A Public Health Perspective of Road Traffic Accidents”. Journal of Family Medicine and Primary Care, 1(2): 144-150. 2012.
	In article
[59]	Refaat, H. “The Contribution of Medical Conditions to Passenger Vehicle Crashes”. Technical Report. National Highway Traffic Safety Administration. NHTSA, Washington D.C., 2009.
	In article
[60]	Useche, S.A., Serge, A. and Alonso, F. “Risky Behaviors and Stress Indicators between Novice and Experienced Drivers”. American Journal of Applied Psychology, 3(1): 11-14. 2015.
	In article
[61]	Tervo, T. Jaakkola, T., Sulander, P., Holopainen, J., Neira, W. and Parkkari, K. “The driver's illness as a cause of traffic accidents”. Duodecim, 127(11): 1147-1153. 2011.
	In article
[62]	Tronsmoen, T. “Associations between driver training, determinants of risky behavior and crash involvement”. Safety Science, 48(1): 35-45. 2009.
	In article
[63]	Reason, J., Manstead, A., Stradling, S., Baxter, J. and Campbell, K. “Errors and violations on the roads: A real distinction?”. Ergonomics, 33: 1315-1332. 1990.
	In article
[64]	Alonso, F., Esteban, C., Useche, S.A. and López de Cózar, E. “Prevalence of Physical and Mental Fatigue Symptoms on Spanish Drivers and Its Incidence on Driving Safety”. Advances in Psychology and Neuroscience, 1(2): 10-18. 2016.
	In article
[65]	Wang, P. and Lin, R. “Coronary heart disease risk factors in urban autobus drivers”. Public Health, 115(1): 261-264. 2001.
	In article
[66]	Belkic, K., Savic, C., Theorell, T., Rakic, L., Ercegovac, D. and Djordjevic, M. “Mechanisms of cardiac risk among professional drivers”. Scandinavian Journal of Work Environment and Health, 20(2): 73-86. 1994.
	In article
[67]	Greiner, B.A. and Krause, N. “Observational stress factors and musculoskeletal disorders in urban transit operators”. Journal of Occupational Health Psychology, 11(1): 38-51. 2006.
	In article
[68]	Pokorny, M.L.I., Blom, D.H.J. and van Leeuwen, P. “Shifts, duration of work and accident risk of bus drivers”. Ergonomics, 30(1): 61-88. 1987.
	In article
[69]	Cendales-Ayala, B., Useche, S.A., Gómez-Ortiz, V. and Bocarejo, J.P. “Bus Operators' Responses to Job Strain: An Experimental Test of the Job Demand-Control Model”. Journal of Occupational Health Psychology. May 2016. [Epub ahead of print].
	In article
[70]	Kontogiannis, T. “Self-reports of aberrant behaviour on the roads: errors and violations in a sample of Greek drivers”. Accident Analysis & Prevention, 34(3): 381-99. 2002.
	In article
[71]	Jägerbrand, A.K. and Sjöbergh, J. “Effects of weather conditions, light conditions, and road lighting on vehicle speed”. Springerplus, 5: 505. 2016.
	In article
[72]	Friesen, A.R. and Schube, P.G. “Behavioral characteristics of dangerous drivers - Importance of correction”. California Medicine, 92(4): 274-276. 1960.
	In article
[73]	Paxion, J., Galy, E. and Berthelon, C. “Mental workload and driving”. Frontiers in Psychology, 5: 1344. 2014.
	In article
[74]	Philip, P., Sagasge, P., Moore, N., Taillard, J. and Horne, J.A. “Fatigue, sleep restriction, and driving performance”. Accident Analysis & Prevention, 37: 473-478. 2005.
	In article
[75]	Thomas, P., Morris, A., Talbot, R. and Fagerlind, H. “Identifying the causes of road crashes in Europe”. Annals of Advances in Automotive Medicine, 57: 13-22. 2013.
	In article
[76]	Kompier, M.A., Aust, B., van den Berg, A.M. and Siegrist, J. “Stress prevention in bus drivers: Evaluation of 13 natural experiments”. Journal of Occupational Health Psychology, 5(1): 11-31. 2000.
	In article
[77]	Lamb, S. and Kwok, K.C. “A longitudinal investigation of work environment stressors on the performance and wellbeing of office workers”. Applied Ergonomics, 52, 104-11. 2016.
	In article
[78]	Thayer, J.F., Verkuil, B., Brosschot, J.F., et al. “Effects of the Physical Work Environment on Physiological Measures of Stress”. European journal of cardiovascular prevention and rehabilitation: official journal of the European Society of Cardiology, Working Groups on Epidemiology & Prevention and Cardiac Rehabilitation and Exercise Physiology, 17(4): 431-439. 2010.
	In article
[79]	Gee, G.C. and Takeuchi, D.T. “Traffic stress, vehicular burden and well-being: a multilevel analysis”. Social Science & Medicine, 59: 405-414. 2004.
	In article
[80]	Rowden, P., Matthews, G., Watson, B. and Biggs, H. “The relative impact of work-related stress, life stress and driving environment stress on driving outcomes”. Accident Analysis & Prevention, 43(4): 1332-1340. 2011.
	In article
[81]	Knipling, R.R., Hickman, J.S. and Bergofen, G. “Effective Commercial Truck and Bus Safety Management Techniques”. Transportation Research Board. TRB, Washington DC, 2003.
	In article
[82]	Deng, T. and Nelson, J. “Recent Developments in Bus Rapid Transit: A Review of the Literature”. Transport Reviews: A Transnational Transdisciplinary Journal, 31, 69-96. 2012.
	In article
[83]	Useche, S.A., Alonso, F., Cendales, B., Autukevičiūtė, R. and Serge, A. “Job strain, Burnout and Road Accidents in the Field of Public Transportation: The Case of City Bus Drivers”. Journal of Environmental and Occupational Science. 2017. [Publication in Advance].
	In article
[84]	Gómez, V. “Assessment of psychosocial stressor at work: Psychometric properties of the Spanish version of the JCQ (Job Content Questionnaire) in Colombian workers”. Revista Latinoamericana de Psicología, 43(2): 329-342. 2011.
	In article
[85]	Siegrist J. Adverse health effects of high-effort/low-reward conditions. Journal of Occupational Health Psychology. 1996; 1: 27-41.
	In article		View Article  PubMed
[86]	Siegrist, J., Wege, N., Pühlhofer, F. and Wahrendorf, M. “A short generic measure of work stress in the era of globalization: effort–reward imbalance”. Int Arch Occup Environ Health, 82, 1005-1013. 2009.
	In article
[87]	Gómez, V. “Assessment of psychosocial stressor at work: Psychometric properties of the Spanish version of the ERI (Effort-Reward Imbalance Questionnaire) in Colombian Workers”. Revista de Psicología del Trabajo y de las Organizaciones, 26(2), 147-156. 2010.
	In article
[88]	Maslach, C. and Jackson, S.E. “Maslach Burnout Inventory” (2nd Edition). Psychologists Press, Palo Alto, 1986.
	In article
[89]	Maslach, C., Jackson, S.E. and Leiter, M.P. “Maslach Burnout Inventory manual” (3rd Edition). Consulting Psychologists Press, Palo Alto, 1996.
	In article
[90]	García, J.M., Herrero, S. and León, J.L. “Validez factorial del Maslach Burnout Inventory (MBI) en una muestra de trabajadores del Hospital Psiquiátrico Penitenciario de Sevilla”. Apuntes de Psicología, 25(2): 157-174. 2007.
	In article
[91]	Alonso, F., Esteban, C., Sanmartin, J. and Useche, S.A. “Consistency Between the Subjective Perception of Feeling Indisposed, the Decision to Drive and Driving Performance”. Science Journal of Public Health, 4(6): 482-488. 2016.
	In article
[92]	Sangaleti, C.T., Trincaus, M.R., Baratieri, T., Zarowy, K., et al. “Prevalence of cardiovascular risk factors among truck drivers in the South of Brazil”. BMC Public Health, 14: 1063. 2014.
	In article
[93]	Söderberg, M., Rosengren, A., Hillström, J., Lissner, L. and Torén, K. “A cross-sectional study of the relationship between job demand-control, effort-reward imbalance and cardiovascular heart disease risk factors”. BMC Public Health, 21(12): 1102. 2012.
	In article
[94]	Peter, R., Geibler, H., and Siegrist, J. “Associations of effort-reward imbalance at work and reported symptoms in different groups of male and female public transport workers”. Stress Medicine, 14: 175-182. 1998.
	In article
[95]	Kivimäki, M., Singh-Manoux, A., Nyberg, S., Jokela, M. and Virtanen M. “Job strain and risk of obesity: Systematic review and meta-analysis of cohort studies. Int J Obes (Lond), 39(11): 1597-1600. 2015.
	In article
[96]	Kivimaki, M., Head, J., Ferrie, J.E., Shipley, M.J., Brunner, E., Vahtera, J. and Marmot M.G. “Work stress, weight gain and weight loss: evidence for bidirectional effects of job strain on body mass index in the Whitehall II study”. International Journal of Obesity, 30: 982-987. 2006.
	In article
[97]	Alonso, F., Esteban, C., Useche, S.A. and Faus, M. “Smoking while Driving: Frequency, Motives, Perceived Risk and Punishment”. World Journal of Preventive Medicine, 5(1), 1-9. 2017.
	In article
[98]	Siegrist, J. and Li, J. “Associations of Extrinsic and Intrinsic Components of Work Stress with Health: A Systematic Review of Evidence on the Effort-Reward Imbalance Model”. International Journal of Environmental Research and Public Health, 13(4): 432. 2016.
	In article
[99]	Schneider, S. and Becker, S. “Prevalence of physical activity among the working population and correlation with work-related factors: results from the first German National Health Survey”. Journal of Occupational Health, 47(5): 414-423. 2005.
	In article
[100]	Rose, S. and Wojcik, J.R. “The Health Habits and Physical Activity of Student Truck Drivers”. The Winthrop McNair Research Bulletin, 1(14): 68-76. 2015.
	In article
[101]	Burr, H., Formazin, M. and Pohrt, A. “Methodological and conceptual issues regarding occupational psychosocial coronary heart disease epidemiology”. Scandinavian Journal of Work, Environment & Health, 42(3): 251-255. 2016.
	In article
[102]	Vieria, M.C., Sperandei, S. and Reis, A. “Physical activity overcomes the effects of cumulative work time on hypertension prevalence among Brazilian taxi drivers”. Journal of Sports Medicine and Physical Fitness. Feb 2015. [Epub ahead of print].
	In article