Core Self-evaluations and Psychological Health among Nurses: The Mediating Role of Work-family Conflict

_____________________________________________________________________________________________________ Changes in the workforce demographics have led many individuals, particularly women, to experience work-family conflict as they juggle between their work and family roles. However, not much is known about the role of work-family conflict in the relationship between positive personality traits, namely, core self-evaluations and psychological health, among nurses. Thus, this study presents a model which examines the impact of core self-evaluations on nurses’ psychological health (i.e., psychological distress and life satisfaction) and whether work-family conflict will have a mediating influence on such relationship. Based on the ecological systems theory and the conservation of resources theory, the model proposes that core self-evaluations will have a direct effect on work-family conflict, life satisfaction and psychological distress in nurses. In addition, it is hypothesised that core selfevaluations will have an indirect effect on life satisfaction and psychological distress through workfamily conflict. Finally, this model highlights the importance of core self-evaluations as personal resources that can protect nurses from work-family conflict and enhance their psychological health.


Introduction
In the past few decades, work-family conflict has become a common phenomenon among working women due to the changing scenarios of workforce demographic, family characteristics, and the increasing usage of new technology in the work environment. The multitasking responsibilities performed in the two most important domains of a woman's life (i.e., work and family) have become sources of stress that impacts psychological health. The process of juggling between work and family responsibilities have exposed women to higher levels of stress, which may eventually lead to mental health problems if the burden becomes unbearable.

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Most extant research on the contributing factors for nurses' experience of work-family conflict and psychological health in the Western (McVicar, 2003;Yildirim & Aycan, 2008;Pisanti et al., 2011) and Malaysian contexts (Emilia & Ismail, 2007;Fauziah et al., 2006;Nazatul et al., 2008;Raja Lexshimi et al., 2007;Sharifah et al., 2011) have tended to focus on certain aspects of job demands as the antecedents of these variables. Limited studies have considered personal resources, in particular, positive personality traits, as determinants of work-family conflict (Allen et al., 2012;Eby, Casper, Lockwood et al., 2005;Michel & Clark, 2011) and psychological health (Judge et al., 2012). Thus, this study proposes a model to investigate the association of core self-evaluations and psychological health among nurses. The model also examines the mediating role of work-family conflict in the association between core self-evaluations and psychological health.
In the context of this study, psychological health was conceptualised as an integrative construct that covers both the positive and negative dimensions of mental states. This conceptualisation is consistent with other studies which noted that the assessment of psychological health should be measured based on the absence of negative symptoms as well as the presence of healthy psychological well-being (Bartlett & Coles, 1998;Dagenais-desmarais et al., 2014;Massé et al., 1998;World Health Organization, 2004). Specifically, the proposed model measures psychological health using two indicators, namely, psychological distress and life satisfaction, which represents the negative mental states and positive signs of well-being, respectively.

Ecological Systems Theory
This theory postulates that development is based on the ongoing interactions between the individual and the environment (Brofenbrenner, 1979). Specifically, this theory conceptualises the environment in the context of four levels of ecological systems that are nested within one another: the microsystem, the mesosystem, the exosystem, and the macrosystem. The proposed model used this theory to examine the two main domains of a nurse's life (i.e., work and family) and how the interaction between them in the mesosystem impacts well-being.

Conservation of Resources Theory
The conservation of resources theory highlights the role of resources in explaining how an individual deals with stressful life events, such as, work-family conflict, that threatens well-being. This theory suggests that stress occurs if a person is exposed to threats involving losing resources, actually losing resources, or not being able to gain resources (Hobfoll, 1989). Specifically, this theory explains that individuals who have adequate resources are less vulnerable to stressful situations (Hobfoll, 1989). By employing this theory, the proposed model hypothesises that resource gain in the form of personal resources can offset the negative impact of resource loss for nurses when they are facing work-family conflict. Thus, nurses with more resources are expected to manage the demands of their work and family successfully, henceforth leading them to feel more satisfied with life and experience less distress.

Core Self-Evaluations and Psychological Health
Core self-evaluations are "the fundamental assessments that people make about their worthiness, competence, and capabilities" (Judge, Bono, Erez, & Locke, 2005, p. 257). Core self-evaluations comprise four different specific traits, namely, emotional stability, self-esteem, locus of control, and generalised self-efficacy (Chang, Ferris, Johnson, Rosen, & Tan, 2012;Judge et al., 2005). These four elements of traits focus on positive beliefs on one's own ability and self-worth that can influence behaviours. Presently, there are only a handful of empirical studies that have demonstrated the www.msocialsciences.com significant association between core self-evaluations and health and well-being. This is because most of the previous studies on core self-evaluations have concentrated on the organisational context (Tsaousis, Nikolaou, Serdaris, & Judge, 2007), while less attention has been given to health and wellbeing (Judge at el., 2005).
Several studies have reported that core self-evaluations are negatively associated with psychological distress (Best, Stapleton & Downey, 2005;Chang et al., 2012;McNall & Michel, 2017;Tsaousis et al., 2007). In contrast, core self-evaluations have been found to be positively related to life satisfaction (Chang et al., 2012;Judge, Locke, Durham & Kluger, 1998;Rey & Extremera, 2014;Song, Kong & Jin, 2013). Consistent with the conservation of resources theory, the findings of the previous literature emphasise the importance of core self-evaluations as personal resources in fostering healthy psychological well-being. Based on the review of empirical literature and the conservation of resources theory, the following hypotheses are proposed: Hypothesis 1a: There is a significant negative association between core self-evaluations and psychological distress. Hypothesis 1b: There is a significant positive association between core self-evaluations and life satisfaction.

Core Self-Evaluations and Work-Family Conflict
Work-family conflict is defined as "a form of inter-role conflict in which role pressures from the work and family domains are mutually incompatible in some respects" (Greenhaus & Beutell, 1985, p.77). Specifically, it refers to the incompatibility between work and family roles. The literature has highlighted the importance of personality or dispositional variables as the main contributing factors for work-family conflict (Allen et al., 2012;Eby et al., 2005;Michel & Clark, 2011). Although there are a handful of studies which reported that personal characteristics contribute to work-family conflict, they mainly focused on negative traits or personalities (Allen et al., 2012;Michel & Clark, 2011). To date, only a few studies have focused on positive traits or personalities, particularly, core self-evaluations, and how they influence work-family conflict. For example, Boyar and Mosley (2007) found that core self-evaluations were negatively associated with work-family conflict among 124 employees at a retirement center or nursing home in the USA. In another study, Michel and Clark (2013) examined the association between core self-evaluations and work-family conflict among 380 employees in the USA. By utilising a direct approach to evaluate core self-evaluations, they found that core selfevaluation was a significant predictor of both directions of work-family conflict. Likewise, Haines, Harvey, Durand and Marchand (2013) investigated core self-evaluations, work-family conflict, and burnout among 289 police officers and civilian staff. Their results showed that core self-evaluations were negatively associated with both work-to-family conflict and family-to-work conflict. Based on these findings, the following hypothesis was formulated: Hypothesis 2: There is a significant negative association between core self-evaluations and workfamily conflict.

Work-Family Conflict and Psychological Health
In the work-family literature, work-family conflict is a major stressor that has a negative impact on individual well-being. Numerous studies have discussed the consequences of work-family conflict on both physical and psychological health. In the context of psychological health, most prior studies have conceptualised psychological health using multiple dimensions, including, work-related psychological health, family-related psychological health, and general psychological health (Allen, Herst, Bruck, & Sutton, 2000;Amstad, Meier, Fasel, Elfering, & Semmer, 2011;Greenhaus, Allen, & Spector, 2006;Nohe, Meier, Sonntag, & Michel, 2015).
In the context of the nursing profession, burnout has been extensively discussed in the work-family literature (Gisler et al., 2018), whereas limited studies have focused on domain-unspecific psychological health outcomes such as psychological distress and life satisfaction (Amstad et al., www.msocialsciences.com 2011). Earlier studies have shown that work-family conflict has a negative relationship with psychological distress in the nursing population (Burke & Greenglass, 1999;Hao, Wu, Liu, Li, & Wu, 2015;Minnotte, Gravelle & Minnotte, 2013;Zhang, Duffy, & De Cattillero, 2017). In contrast, workfamily conflict has been found to be positively associated with life satisfaction among nurses (Yildrim and Aycan, 2008). In the Malaysian context, Rashid, Nordin, Omar, and Ismail (2013) examined 689 nurses in public hospitals in Malaysia and reported that work-family conflict was negatively associated with overall satisfaction. Similarly, Husin and Noor (2007) reported that work-family conflict was positively related to psychological strain among nurses in the government hospitals in the East Coast of Peninsular Malaysia. Based on the above literature review, it can be assumed that work-family conflict impacts nurses' psychological health, thus the following hypotheses are proposed: Hypothesis 3a: There is a significant positive association between work-family conflict and psychological distress. Hypothesis 3b: There is a significant negative association between work-family conflict and life satisfaction.

Work-Family Conflict as a Mediator
The literature has established the mediating impact of work-family conflict on the association between work-family factors and employee well-being. For instance, the integrative model of work-family interface developed by Frone, Russel, and Cooper (1992) is an established model that emphasises the role of work-family conflict as a mediator in the relationship between various types of work and family domain antecedents and a wide range of individual outcomes. Several other models have also proposed that work-family conflict is an important mediating variable between work-family conditions and individual outcomes (Carlson & Perrewe, 1990;Michel, Mitchelson, Kotrba, LeBreton, & Baltes, 2009). However, most studies in the work-family literature have focused on work-family conflict as a mediator between work-family demands and individual well-being (Eby et al., 2005;Winefield, Boyd, & Winefield, 2014). Thus, the proposed framework focuses on personal resources as the determinants of work-family conflict and how it can influence psychological health. Based on these findings, the following hypotheses are proposed: Hypothesis 4a: Work-family conflict mediates the association between core self-evaluations and psychological distress. Hypothesis 4b: Work-family conflict mediates the association between core self-evaluations and life satisfaction.

The Proposed Model
The proposed model was developed based on the ecological systems theory and the conservation of resources theory. The ecological systems theory posits that the interaction between the work and family domains impacts well-being (Brofenbrenner, 1979). Additionally, the conservation of resources theory suggests that resource gain, unlike resource loss, enhances individual well-being (Hobfoll, 1989), Thus, nurses with greater resources are less vulnerable to resource loss, and are therefore likely to experience greater well-being.
The proposed model also extends previous models by highlighting core self-evaluations as a contributing factor to work-family conflict and psychological health among nurses. In this context, core self-evaluations have been identified as a useful personal resource that may protect nurses from stressful situations due to work-family conflict, thus enhance their psychological health. In addition, the proposed model also examines work-family conflict as an important mediating variable in the relationship between core self-evaluations and nurses' psychological health. The proposed model of the study is depicted in Figure 1: www.msocialsciences.com

Conclusion
This model proposes that core self-evaluations have a direct effect on nurses' experience of workfamily conflict and psychological health (i.e., psychological distress and life satisfaction). Additionally, core self-evaluations are also hypothesised to have an indirect effect on psychological health through work-family conflict. The model implies that there is a need to realize the importance of positive personal characteristics on nurses' psychological health. Finally, this research may improve our understanding of psychological health as a multi-dimensional construct by examining psychological distress and life satisfaction as separate dimensions in a single research. By doing this, the present study provides insights into how personal resources, that is, core self-evaluations, can contribute to nurses' psychological distress and life satisfaction differently.