The Effects of Job Demands on Mental and Physical Health in the Group of Police Officers. Testing the Mediating Role of Job Burnout

IntroductionThe dynamic changes that occur in the world of work have posed new challenges for occupational health research (Kompier, 2006). Several researchers have argued that the popular models of job stress (e.g., Job Demands-Control model or Effort-Reward Imbalance model) may have limitations in capturing the new, complex, and often distinctive determinants of job stress and occupational well-being (Hellgren, Sverke, & Naswall, 2008; Ballducci, Schaufeli, & Fraccaroli, 2011). For that reason, more context-specific models of job stress have recently been developed. One of them is the Job Demands-Resources model (JD-R) (Demerouti, Bakker, Nachreiner, & Schaufeli, 2001). This model assumes that each work environment has its own set of job characteristics that determine employees' health and well-being. Job characteristics can be divided into job demands and job resources. According to the JD-R model job demands are connected with poor health, whereas job resources are related to positive work attitudes. In addition to researching direct relationships between job demands and health problems, the JD-R model tries to identify potential mediators which indirectly affect the relationship. One of the most frequently studied mediators in the context of the JD-R model is job burnout.Several studies done on various occupational groups have confirmed that high job demands result in job burnout and this in turn leads to health problems (the so-called energetic process) (e.g., Hakanen, Bakker, & Schaufeli, 2006; Schaufeli & Bakker, 2004). However, most of these studies were conducted in Western (not Eastern) parts of Europe (e.g., Finland, Holland) and have not included police officers. Based on previous investigations, it can be assumed that this group is particularly exposed to high job demands and therefore is also at a great risk of suffering from physical and mental health problems related to high job demands (Colwell, 2009). Police officers are also particularly susceptible to job burnout (Kop, Euwema, & Schaufeli, 1999). Mental health problems among police officers have been observed in numerous studies conducted in various countries, including the USA (Pendleton, Stotland, Spiers, & Kirsch, 1989), Germany (Schmidtke, Fricke, & Lester, 1999), the United Kingdom (Collwell, 2009), Turkey (Gul & Delice, 2011), and also Poland (Dudek, Waszkowska, & Hanke, 1999). Moreover, in previous studies on JD-R mainly mental, not physical aspects of health were taken into consideration. The present research aims to verify the JD-R model and attempts to seek further insights into the processes that lead to poor health through job burnout. It tests how job burnout mediates the negative impact of job demands on mental health (as measured by rates of depression) and physical health (as measured by self-reported physical health complaints) in a group of Polish police officers.The JD-R Model as Theoretical Framework of ResearchThe JD-R model is an attempt to develop earlier occupational stress concepts, including the Job Demands-Control model (JD-C, Karasek & Theorell, 1990), the Job Demands-Control-Support model (DCS, Johnson & Hall, 1988), the Effort-Reward Imbalance model (ERI, Siegrist, Starke, Chandola, Godin, Marmot, Niedhammer, & Peter, 2004) and the Conservation of Resources theory (COR, Hobfoll, 1989). The JD-R model assumes that each occupation involves specific job demands which, in conditions of poor job resources, may lead to poor health (Bakker et al., 2003). Job demands refer to those "physical, social or organizational job aspects that require sustained physical and/or psychological effort and are associated with certain physiological and/or psychological costs" (Demerouti et al., 2001, p. 501). They include role stress, bad working conditions, job monotony, a demanding workload, interpersonal conflicts and organizational constraints. Job resources are related to "physical, social and organizational aspects of the job that: may be functional in achieving work-related goals; reduce job demands and the associated physiological and psychological costs, and stimulate personal growth and development" (Demerouti et al. …