Assumptions are beliefs about a phenomenon or an event acting as a premise to understand a theory . The four assumptions that were the pillars of our work in knowledge synthesizing and model construction of the nurses’ workplace social capital theory are: 1) The essentiality of and the necessity for a comprehensive understanding of this phenomenon before interventions; 2) The necessity of a comprehensive understanding of the constitution of nurses’ workplace social capital itself, the potential determinants for its occurrence and the ensuing outcomes; 3) A conceptual model with a graphic display, supported by empirical evidences, can help to produce a compact representation of a phenomenon which could enable to form a framework for future investigations and practical applications; and 4) The necessity for a continuous evaluation of nurses’ workplace social capital to propel the evolution of the model in response to the rapid changes in the profession of nursing.
The focal concept of the conceptual model
Focal concept(s) specification is the first step in the process of theory synthesis. The focal concept of “nurses’ workplace social capital” was specified as the beginning of developing our conceptual model. We justified our approach because the workplace social capital is a relatively new concept in the field of nursing and yet, it increasingly has gained traction and importance in influencing work-life of the nursing profession.
Relational networks (structure of relational networks) and the assets embedded in these networks (e.g. trust, reciprocity) are the key attributes to social capita; the attribute of relational network indicates the “doing” among people who are weaving the fabric of workplace social capital, whereas the assets suggest the “feeling” among them [2, 16, 17]. These theoretical notions have been adopted by researchers in the field of academic nursing, indicating their validity and applicability within the concept of nurses’ workplace social capital [14, 18–20]. Meanwhile, nurses’ workplace social capital can be classified into three types, bonding, bridging, and linking. Bonding and bridging in the context of social capital describe relationships established within and/or among groups at the same professional and power level and, therefore, is regarded as horizontal social capital; in contrast, linking social capital represents relationships across different strata of power and is considered vertical social capital [4, 14, 21]. The diagram of the constitution of this focal concept is depicted in Fig. 1.
Related factors and relational statements in the conceptual model
The second step in the process of theory synthesis is to identify factors that are related to the focal concept and to analyze how these factors influence each other; while, the third step is to logically organize all the concepts and statements in a diagrammatic form . The ideas of “inventory of determinants or results” and “theoretical blocks” are the underpinning principles of these two processes [6, 22]. We also benefitted from Miller’s theory of human thought and cognition  to implement the second step in our theory synthesis. Social capital is the subjective perceptions of individuals about their relationships with others at work; in other words, social capital can be interpreted as a conglomerate of the complex interactions among our thoughts, perceptions, and cognitions about our work environment. According to Miller, emerging cognitive events such as nurses’ workplace social capital, arise when certain existing inputs (determinants) lead to outcomes. Therefore, we have arranged all the influencing factors on social capital under the themes of inputs (determinants), events (nurses’ workplace social capital) and outcomes, and have specified their relationships
Accordingly, we developed a template to record the summarized empirical evidences in which the “Focal Concept (event)” was set in the middle column, while “Inputs” (determinant) and “Outcomes” were placed into the left and right columns, respectively. We identified the related concepts by reviewing the selected literature and then classified these concepts under the categories of Event, Inputs or Outcomes, per their content meaning and conveyed membership. Furthermore, similar but less general, sub-concepts were collapsed into more comprehensive summary concepts to reach the parsimony of the newly synthesized model. For example, different types of leadership and overall leadership quality were categorized under the summary concept of “leadership”. This summarized concept then was grouped under the high-order concept of “organizational factors” along with sub-concepts of “nurse management”, “workplace activities” and “hospital type”.
Similarly, relationships between inputs/outcomes and the focal concept were collapsed and classified to higher-order relational statements. Five major relational statements, illustrating the relationships among these related concepts and the focal concept, were proposed for our conceptual model. These related concepts and relational statements are discussed below.
Determinants of nurses’ workplace social capital and their relationships
The first recommended relational statement in our proposed conceptual model is the organizational factors that influence the development of nurses’ workplace social capital. In the nursing literature, two types of leadership have been described as the determinants of nurses’ workplace social capital: 1) Transformational leadership has been recognized as a strong predictor of nurses’ workplace social capital ; 2) Authentic leadership has been identified as a significant influencer of workplace social capital . Additionally, research suggests that overall leadership quality significantly influences workplace social capital over time . Amicable and situation-responsive nurse management at a unit has a positive and chronic influence on the development of workplace social capital .
Nurses’ workplace social capital is influenced by workplace behaviors and/or activities. We would like to use the term “Effect Modifiers” to describe the variables that influence, either negatively or positively, the nurses’ workplace social capital. For example, communication can be classified as an effect modifier of the nurses’ workplace social capital; poor quality and ineffective communication at work can quickly destroy nurses’ workplace social capital . The style of communication, which endorses understanding and effective comprehension of messages, can strengthen the nurses’ workplace social capital. The impact of constructive communication, as a positive effect modifier, was reported by Vardaman et al. . The authors reported on the long-term positive effects of the communication tool, Situation-Background-Assessment-Recommendation (SBAR) on nurses’ workplace social capital .
The spectrum of effect modifiers of nurses’ workplace social capital is broad and not exclusive to communication. For example, visual management tools in nurses’ daily work have been reported to positively modify nurses’ workplace social capital ; research has supported the positive effects of the organizational intervention of participatory workshops on the topic of utilizing assistive devices in patient handling, or group-based physical exercise on nurses’ workplace social capital [21, 30]. Finally, urgency, efficiency, and immediacy of delivery of healthcare services can be viewed as a positive effect modifier on nurses’ workplace social capital. Research supports the notion of higher workplace social capital among nursing professionals working in critical care hospitals compared with those working in community or academic hospitals .
The second recommended relational statement in our proposed conceptual model is the individual factors that influence the development of nurses’ workplace social capital.
Shin and Lee  reported that the score of workplace social capital varied among nurses’ groups with different levels of education, years of experience and years in the present unit. The scores of workplace social capital perceived by nurses with a graduate degree, providing direct care (work role) and having full-time employment status were lower than those who had bachelor’s education, provided non-direct care and had part-time/casual work employment . Moreover, employees with higher emotional intelligence are more dexterous in establishing constructive communication , in their interactions with others  and in developing interpersonal relational networks . The positive influence of emotional intelligence on workplace social capital has been confirmed in the nursing population .
Outcomes of nurses’ workplace social capital and their relationships
Eighteen outcomes, 17 positive and one negative, were identified in the nursing literature. These outcomes were then collapsed under the summary concepts to reach theoretical succinctness. Three summary concepts were abstracted from the more concrete outcomes: nurses’ outcomes (positive and negative), patients’ outcomes and organizational outcomes (Fig. 1).
The third relational statement of the conceptual model is nurses’ outcomes, which is influenced by the nurses’ workplace social capital. The less general concepts, under the summary term “nurses’ outcomes”, are 13 positive and one negative outcomes. The 13 positive nurses’ outcomes range from attenuation of emotional exhaustion, lower burnout and mental distress, increase in healthy self-behaviors, improvement in job satisfaction, strengthening the intention to stay, knowledge sharing, organizational commitment, professional commitment, motivation to improve professional capabilities, willingness to mentor/be mentored, adoption of evidence-based practice and prevention of occupational injuries and accidents; while, social exclusion is the only negative outcome of nurses’ workplace social capital.
Nurses’ workplace social capital is negatively related to emotional exhaustion and burnout [15, 36]. Additionally, it may relieve nurses’ mental distress and can improve nurses’ health status . Furthermore, nurses’ workplace social capital is positively associated with job satisfaction [15, 19, 32] and intention to stay . Nurses who perceive higher workplace social capital are more likely to share their knowledge with others  and develop higher organizational and professional commitments [38, 39]. Meanwhile, they have the willingness to improve their professional capabilities , mentor/be mentored at work  and adopt evidence-based practices . Finally, workplace social capital is described by nurses as a major strategy for prevention of occupational injuries and accidents . However, workplace social capital is also reported to result in social exclusion; strong bonding among the nursing staff can create strong relational ties that may influence their acceptability of newcomers [41, 42].
The fourth relational statement is patients’ outcomes which is influenced by the nurses’ workplace social capital. “Patients’ outcomes” is a summary of two sub-concepts. First, a higher nurses' workplace social capital leads to a better quality and more efficient delivery of care [13, 15, 32]. Second, nurses’ self-report of patient safety also is indicative of the positive impacts of high nurses’ workplace social capital on patients’ outcomes .
The fifth relational statement is organizational outcomes which is influenced by nurses’ workplace social capital. Under the summary concept of “organizational outcomes” we have listed two distinct outcomes, better clinical risk management and improved unit effectiveness. Nurses’ workplace social capital is positively correlated with the betterment of clinical risk management [43, 44]; also, improved unit effectiveness, which has been defined as the capability of a unit to effectively and timely provide healthcare services, is positively correlated with the nurses’ workplace social capital .
An integrated representation of the conceptual model
Finally, all the related concepts and relational statements were integrated into four “theoretical blocks” [6, 45] in our conceptual model (Fig. 1). This conceptual model illustrates the determinants, constitution and outcomes of nurses’ workplace social capital and specifies the relational statements among these concepts. Our conceptual model, with both graphic and narrative presentations, provides an updated and comprehensive information about nurses’ workplace social capital. The definitions of the main concepts in the synthesized conceptual model are presented in Table 1.
Nurses’ workplace social capital (Block 3) may be influenced by both organizational factors (Block 1) and nurses’ individual factors (Block 2). Organizational factors include leadership (transformational leadership, authentic leadership and leadership quality), nurse management, workplace activities (communication, daily visual management tool use, participatory workshops and group-based physical exercise) and hospital type. Nurses’ individual factors comprise the less general concepts of educational level, years of experience, years in current unit, work role, employment status and emotional intelligence. We also have demonstrated the interactions between these two categories of determinants, marked by a double arrow line in the model. These interactions are indicatives of the mutual supplementary effects of organizational factors and individual factors.
Eighteen variables were identified as the less general outcomes, which were classified under three themes: nurses’ outcomes, patients’ outcomes, and organizational outcomes (Block 4). The improvements in nurses’ workplace social capital can lead to 17 positive outcomes. However, the strengthening of bonding social capital may lead to social exclusion.
We have demonstrated the possible interactive relationships among these variables; we emphasize the term “possible” because most of the outcomes were identified from cross-sectional studies which have limitations in discerning the symmetry (direction) of a statement [25, 32, 38, 40, 44]. Future prospective studies can either support or refute our proposed model.