The Buffering Effect of Perceived Organizational Support on the Relationships Among Workload, Work–Family Interference, and Affective Commitment: A Study on Nurses

ABSTRACT Background Minimal research has been conducted to explore the associations among workload, work-to-family conflict, family-to-work conflict, support, and affective commitment. Purpose This study was designed to explore the moderating role of perceived organizational support on the mediating effects of work-to-family conflict, family-to-work conflict in perceived workload, and affective commitment linkage. Methods The data were collected using a self-report survey from 164 nurses working at two public hospitals. The hypothesized model was tested using PROCESS macro. Results Perceived organizational support was found to influence the mediating effect of work-to-family conflict on the linkage between workload and affective commitment, yet not to moderate the mediating effect of family-to-work conflict. The results revealed that workload predicts affective commitment negatively and work-to-family conflict positively. However, perceived organizational support was found to change the effect that workload has on affective commitment. The negative effect of workload on affective commitment was found to be weaker for nurses with adequate organizational support. Conclusions/Implications for Practice Perceived organizational support was found to have both main and buffering effects on the emotional attachment of nurses toward their organizations. The findings support the importance of creating supportive work settings to alleviate the adverse effects on nurses of workload and work–family interference.


Introduction
While the growth in the world population and the augmentation of illnesses have increased demands on the nursing profession, healthcare organizations continue to face challenges in retaining qualified nurses. Thus, scholars and practitioners are searching for strategies and policies to enhance the commitment of employees to healthcare organizations. Organizational commitment (OC), a central variable in fostering organizational effectiveness (Wasti, 1999), has been defined as "a psychological state involving employees' decision to remain or not in the same organization" (Meyer & Allen, 1991, p. 67). Among the three subfactors of OC, affective commitment (AC) has gained particular attention, as it relates directly to increased job performance (Reiley & Jacobs, 2019) and reduced absenteeism (Jacobsen & Fjeldbraaten, 2019). AC reflects an "employee's emotional attachment to, identification with, and involvement in the organization" (Meyer et al., 2002, p. 21). Studies conducted on nurses have revealed nurses who are affectively committed to be more likely to remain in their organizations for more years (Chang et al., 2019) and to perceive more professional satisfaction (Barać et al., 2018).
Work overload, a prominent situational factor that affects the OC of employees, reflects an excess in task demands requiring significant amounts of effort (Schulz et al., 1998, p. 91). Work overload may occur because of a shortage of nurses, increases in overtime or patient numbers, or an aging population and may reduce the AC of nurses by stimulating conflicts between work and life spheres. Particularly, the perception of high workload may accelerate work-family interference in terms of both work-to-family conflict (WFC) and family-to-work conflict (FWC), which mainly arise from "the perceptions of insufficient time and energy to successfully perform work and family roles" (Grandey & Cropanzano, 1999, p. 350). Such heightened levels of WFC and FWC may erode an individual's emotional attachment toward their organization (e.g., Yang et al., 2018).
"Perceived organizational support" (POS) is a variable that may significantly and positively influence AC. When employees receive favorable treatment from their organizations, they feel obligated to respond by exercising more effort and committing more to their workplaces. Thus, AC to their organization may increase when nurses perceive increased support from administrators and experience less workload and fewer work-family issues. This study was developed to address the predictive effects of workload and work-family interference (WFC and FWC) and the buffering effect of POS on AC in nurses. In this study, the mediating roles of WFC and FWC on the linkage between workload and commitment and the effects of workload and work-family interference on AC change when nurses perceive organizational support are explored.
This study was conducted using data from Turkey. The status of women in Turkish society has progressed since the founding of the Turkish Republic in 1923. This progress has improved the nursing profession and increased the number of professional women who work as nurses (Bahçecik & Alpar, 2009). Currently, whereas men may work in the nursing profession, women comprise most nurses in Turkey (Bahçecik & Alpar, 2009). In the Turkish healthcare system, nurses in public hospitals are employed as civil servants and thus work either as permanent staff or as annual (temporary) contract employees (S. C. Durmus et al., 2018). Most of the nurses in private hospitals are employed as contract employees. According to the latest Organization for Economic Co-operation and Development (2017) data, Turkey is ranked as one of the worst countries in terms of the nursing ratio, which is approximately 2.1 per 1,000 population. Benligiray and Sonmez (2013) state that the shortage of qualified nurses in Turkey is because primarily of long working hours, work overloading, and inadequate job-training opportunities. Moreover, research has shown most nurses in Turkey are "insensitive" to their organizations, with no or low degrees of commitment (Benligiray & Sonmez, 2013). Excessive workload, day and night shifts, irregular work hours (Yildirim & Aycan, 2008), insufficient salary, and awards seem to result in quitting their job or the profession completely. Therefore, this study may provide important insights to healthcare practitioners in Turkey to help them develop policies to enhance OC and reduce work-to-family interference in nurses.

Theoretical Background
Work overload and affective commitment The adverse outcomes of work overload, a type of pressure that individuals experience in the workplace, include higher levels of emotional exhaustion (e.g., Sianoja et al., 2018) and lower levels of job satisfaction (e.g., Zeytinoglu et al., 2007). Although the significance and severity of work overload depend on the type of job, it is an important factor affecting the healthcare sector, where direct communication with patients and their relatives is intensive. Although workload accelerates with job intensity and working hours, two individuals working in the same organization and having the same task demands may perceive their workload differently. Therefore, workload should be measured in subjective terms rather than in terms of number of hours worked. Accordingly, a high workload should be defined as reflecting the perception of an individual lacking or having insufficient "personal resources needed to fulfill job-related commitments, obligations, and requirements" (Peterson et al., 1995, p. 430).
Researchers have also argued that employees perceiving high levels of work overload are less satisfied and less committed and tend to quit the organization (Malik et al., 2010). A plausible linkage between AC and workload may be explained using the premises of the psychological contract theory (Rousseau, 1990). Under this theory, when an employee perceives an inconsistency between an employer's words and actions, he or she experiences psychological contract breach. Thus, if employees perceive that their workload exceeds a manageable level, they may experience psychological contract breach. As time passes, these employees lose confidence that their employer is acting in their interests and, more importantly, is dealing with them honestly, which erodes their organizational trust and, subsequently, their emotional bonds with their employer. Drawing upon the tenets of this theory and prior research, perceived workload is presumed in this study to be negatively associated with AC.
Work-family interference, workload, and affective commitment Work-family interference has been defined as "inter role conflict where the role pressures from the work and family domains are mutually incompatible in some respect" (Greenhaus & Beutell, 1985, p. 77) and rests on the premise that fulfilling the demands of one domain (family or work) makes it more difficult to accomplish the demands of the opposite domain (Netemeyer et al., 1996). These definitions assume a unidimensional meaning of WFC, with work acting unilaterally on family responsibilities. However, recent studies have highlighted that family responsibilities also interfere with work responsibilities. In other words, conflict may originate in the family (FWC) and work (WFC) contexts. WFC occurs when work-related demands interfere with family responsibilities (e.g., childcare, household chores), whereas FWC occurs when family responsibilities impede work activities (Netemeyer et al., 1996). More particularly, individuals who work beyond their scheduled working hours and do not fulfill their home responsibilities may experience WFC. Conversely, FWC occurs when individuals experience an "inter-role conflict in which the general demands of time devoted to, and strain created by the family interfere with performing work-related responsibilities" (Netemeyer et al., 1996, p. 401). Thus, individuals who are absent from work because of household chores tend to experience FWC. The literature indicates that scholars should focus more attention on both WFC and FWC, as each necessitates different interventions (Mesmer-Magnus & Viswesvaran, 2005).
In line with previous studies conducted with nurses (e.g., Asiedu et al., 2018;Ghislieri et al., 2017), perceived workload is presumed to be positively related to both WFC and FWC. Conservation of resources (COR) theory (Hobfoll et al., 2018) and resource drain theory (Edwards & Rothbard, 2000) may help explain the associations among WFC, FWC, and workload. COR theory argues that conflict arises from limited resources (e.g., energy, time) and the desire of individuals to retain and protect these resources. When employees perceive the risk of losing resources that are valuable and meaningful to them, they tend to experience stress, leading to conflict between the roles of work and family (Hobfoll et al., 2018). Resource drain theory argues that, when a significant amount of resources (e.g., energy and time) are spent in one domain (e.g., family), a few resources are left to invest in other domains such as work, resulting in a conflict between these domains (Edwards & Rothbard, 2000). Following this corollary, perceived workload may be expected to positively predict conflicts in both work and life domains.
As with perceived workload, WFC and FWC are assumed to be negatively associated with AC. Experiencing conflict in either work or home domains has been associated with heightened stress levels (Stoeva et al., 2002), which may influence organizational attitudes and reduce the employee's emotional attachment to his or her organization. Considering the premises of COR, psychological contract, and resource drain theories, the workload is assumed in this study to be a distal workplace strain that is expected to affect WFC and FWC and, in turn, act as proximal predictors of AC in nurses. Thus, we assert the following hypotheses: Hypothesis 1: WFC mediates the relationship between workload and AC. Hypothesis 2: FWC mediates the relationship between workload and AC.
The moderating effect of perceived organizational support As part of the social exchange between employees and their organizations, employees express loyalty and dedication by increasing work performance and reducing absenteeism and turnover (Rhoades & Eisenberger, 2002). Employers reciprocate this loyalty and dedication by offering a decent salary and wages and by showing interest and genuine concern for the well-being of their employees (Dawley et al., 2010). POS plays a critical role in this mutually rewarding social exchange in terms of assuring employees that "their organization stands behind them as they perform their jobs and handle stressful conditions" and assuring employers that employees value and respect their organization (George et al., 1993;cited in Dawley et al., 2010, p. 241). Therefore, in line with the reciprocity principle, it is reasonable to expect that "the obligation to exchange caring for caring" acts to enhance employees' AC to the personified organization (Foa & Foa, 1980;cited in Arshadi, 2011cited in Arshadi, , p. 1101. In other words, POS could directly influence nurses' AC toward their organizations. POS may also positively influence AC by satisfying the affiliation needs of employees (Eisenberger et al., 1986). The satisfaction of socioemotional needs may create a sense of belonging to an organization, which may lead employees to incorporate this sense into their social identity. Multiple studies have elucidated the relationship between POS and AC using the social identity and social exchange theory (Blau, 1964). Meyer and Allen (1991) argued that employers satisfying the needs of their employees through effort and status recognition helps employees create a social identity that bolsters OC. Therefore, POS could positively influence AC and may buffer the effects of WFC, FWC, and workload by reducing perceived stress. For example, if work-related concerns interfere with an employee's home responsibilities, he or she may experience WFC. However, if that employee works for a supportive organization that makes accommodations for home responsibilities, he or she may experience lower workload-related stress and WFC and thus have greater emotional attachment toward their employer. In line with the premises of the norm of reciprocity and social identity theory, we assert the following hypothesis: Hypothesis 3a: POS moderates the mediated relationship between workload and AC via WFC. The mediated relationship is weaker in individuals who perceive a higher level of organizational support than those with lower levels of POS. Hypothesis 3b: POS moderates the mediated relationship between workload and AC via FWC. The mediated relationship is weaker in individuals who perceive a higher level of support from their organizations than those with lower levels of POS.
These hypothesized relations are depicted in Figure 1.

Participants and Procedures
Before collecting the data, ethical approval for this study was received from the Ethics Commission of Hacettepe University (approval number: 35853172/433-3548), and permission was obtained from the authors to use the relevant scales for research purposes. All of the participants read and signed informed consent, which provided a brief description of the study aims and their rights (e.g., voluntary participation, withdrawal rights). No incentives were offered for participation.
The Buffering Effect of Organizational Support VOL. 29, NO. 2, APRIL 2021 Data were gathered from nurses working at two public hospitals located in Ankara, the capital city of Turkey, in December 2016. Throughout the data collection period, the total number of nurses working at these hospitals was 390. The sample size was determined based on the suggestions of Tabachnick and Fidell (2013) as well as power analysis. The optimal sample size was calculated using the formula N ≥ 104 + m (in which m represents the number of independent variables) and was found to be at least 108 participants (Tabachnick & Fidell, 2013). A power analysis was conducted using an alpha of .05, and it was found that 194 participants were required to achieve a power of 0.80. Presuming a maximum attrition rate of 30%, 250 questionnaires were delivered via convenience sampling and 177 were returned (response rate: 71%). Considering the suggestions of Tabachnick and Fidell (p. 63), 13 of the collected questionnaires were excluded because of a large number of missing values (more than 50% missing data). Therefore, the total number of respondents was 164. Women comprised 94.5% of the sample (n = 155), which is representative of the nursing population in Turkey. The age of the participants ranged between 21 and 60 years (mean = 36 years). Most were married (73%, n = 120) and had children (69.5%, n = 114). Most were employed in alternative (nondaytime) working arrangements (67% alternative vs. 33% daytime work) and worked on weekends (79%). Weekly working hours exceeded 40 hours (74%).

Instruments
The questionnaire consisted of five sections, covering demographics (gender, age, marital status, and children), work-related conditions (total number of working hours, weekend working, and working schedule), and study variables (i.e., workload, WFC, FWC, POS, and AC). All of the study variables were measured using a 5-point Likert-type scale ranging from strongly disagree (1) to strongly agree (5).
Affective commitment scale AC was measured using the scale of Meyer et al. (1993). Wasti (1999) added two more items to the original scale to create the Turkish version of this scale, which contains eight items (e.g., "I really feel as if this organization's problems are my own"). The Cronbach's alpha for the Turkish version of the AC scale was found to be .77.

Work overload scale
The Turkish version of Peterson et al.'s (1995) 11-item scale, created by Derya (2008), was used to assess the work overload status of the participants. A sample item is "My workload is too heavy." Higher scores indicate higher levels of perceived workload. The internal reliability coefficient of Cronbach's alpha was found to be .84 for this scale.
Work-family conflict and family-work conflict Work-family interference was measured using the Turkish version of the 10-item scale of Netemeyer et al. (1996), created by Derya (2008). The first set of five items measures WFC, and the second set of five items measures FWC. Scale reliability in this study was found to be .92 for WFC and .93 for FWC.

Perceived organizational support
The short version of the POS scale, developed by Eisenberger et al. (1986), was adopted to measure the perceptions of the participants regarding the support provided by their organizations. The items on this scale were modified by V. Durmus (2011) to better reflect the working environment faced by healthcare workers. The modified Turkish version was utilized in this study. A sample item is "Help is available from the organization when I have a problem." Respondents rate 12 items, with higher scores indicating higher levels of perceived support. The Cronbach's alpha coefficient for this scale was found to be .93.

Preliminary Analysis
A confirmatory factor analysis was conducted to examine whether the scale items measured the study variables adequately. In the specified measurement model, all of the scale items were assigned to five study variables. Initial examination of the fit indices suggested a poor fit. After examining the modification indices and factor loadings, one workload item (Item 7: "I can finish my work on time") was excluded because of insignificant factor loading. The revised model yielded an acceptable model fit (w 2 (530) = 710.43, p < .05, w 2 /df = 1.34, comparative fit index = .94, Tucker-Lewis index = .94, root mean square error of approximation = .05, squared multiple correlation = .07) using the criteria of Schermelleh-Engel et al. (2003). As all of the item-construct relations were found to be significant, composite scores of WFC (n = 5 items), FWC (n = 5 items), workload (n = 10 items), POS (n = 12 items), and AC (n = 8 items) were created by taking the average of the responses. On the basis of the composite scores, we calculated the means and intercorrelations among the variables. The mean score, correlation coefficients, and scale reliabilities of the instruments are presented in Table 1. The Pearson correlation coefficients provided initial support for the hypotheses, with the results showing a moderate relationship between AC and workload (r = −.23, p < .01), POS negatively related to WFC (r = −.27, p < .01), and no significant correlation between demographic variables and AC. For the female participants, the mean score of FWC (M = 2.63, SD = 1.04) was significantly lower than the mean score of WFC (M = 3.76, SD = 0.90; t(155) = −12.55, p < .001).

Testing the Hypotheses
In this study, POS was assumed to moderate the impact of WFC, FWC, and workload on AC. Moreover, the impact of workload on AC was assumed to be mediated by WFC and FWC. The PROCESS macro was used to test the moderated mediation model (Hayes, 2018). As suggested by Hayes (2018), initially, the mediating effect of WFC and FWC on the linkage between workload and AC was tested. Working conditions were added as control variables, and the effects of these control variables were found to be insignificant at   Table 2, with workload showing a positive effect on WFC (b = .56, t = 6.74, p < .001) and FWC (b = .36, t = 3.31, p = .001). Unexpectedly, the effects of WFC (b = .13, t = 1.84, p = .060) and FWC (b = −.02, t = −0.35, p = .720) on AC were found to be insignificant, although the effect of WFC was nearly significant. Although the mediating effects of WFC and FWC on workload and AC were found to be insignificant, these mediations may be significant contingent upon the values of POS. Thus, through PROCESS macro, the conditional indirect effect of workload on AC via WFC and FWC was evaluated as a function of POS after controlling for the working format and weekend working. The moderated mediation tests were conducted separately for each WFC and FWC. In Table 3 and Figure 2, the results of the moderated mediation model testing the conditional indirect effect of workload on the AC through WFC for three values of POS are presented (1 SD above and below the mean as well as the mean).
As shown in Table 3 and Figure 2, the moderating effects of POS on workload-WFC and WFC-AC linkages were found to be insignificant. However, as argued in Preacher et al.'s (2007) Figure 3, with a 95% confidence interval. As seen, the conditional meditational effects of WFC (i.e., the indirect effect of workload) at medium and high levels of POS were found to be significant, as the values between the lower and upper bounds (i.e., the confidence intervals) did not contain zero. Thus, confirming expectations, POS moderated the indirect effect of workload on AC through WFC only in medium and high levels of POS. Although workload increases WFC, these heightened levels of WFC contribute to AC when nurses believe that they receive adequate support from their organization. In addition to this buffering effect, POS was found to have a relatively strong main effect (b = .32, p < .01). Accordingly, nurses who perceive high levels of support from their organizations are more likely to have higher emotional attachment toward their organizations (i.e., AC). Note. "Constant" indicates the expected mean value of dependent variables when the value of independent variables is 0. Working format; 1 = daytime working and 2 = other. Weekend work: 1 = yes and 2 = no. AC = affective commitment; POS = perceived organizational support; B = unstandardized regression estimate; β = standardized regression estimate; SE = standard error of unstandardized estimate; WFC = work-family conflict; Boot LLCI = bootstrapping lower level confidence interval; Boot ULCI = bootstrapping upper level confidence interval. *p < .05. **p < .01.

Results of Regression Analyses for Moderated Mediation: Work-To-Family Conflict as Mediator
The Journal of Nursing Research Ozge TAYFUR EKMEKCI et al.
In the second moderated mediation test, we examined the conditional indirect effect of workload on AC via FWC as a function of POS after controlling for the working format and weekend work scheduling. The results of this moderated mediation test are shown in Figure 4. The moderating effects of POS on workload-FWC and FWC-AC linkages were not significant. Besides, bootstrap confidence intervals for conditional indirect effects were insignificant at all levels of POS (low CI [−0.07, 0.06], medium CI [−0.03, 0.06], and high CI [−0.03, 0.10] levels of spousal support). Hence, POS did not moderate the indirect effect of workload on AC through FWC at all levels of POS. Although POS did not have a buffering effect, it was found to have a significant main effect on AC (b = .34, p < .05).
In summary, moderated mediation tests were conducted in this study to assess the mediating effects of work-family interference (WFC and FWC, respectively) on the linkage between workload and AC. Then, the moderating effects of POS on two of the hypothesized mediated relationships ([a] workload → WFC → AC; [b] workload → FWC → AC) were explored using the same models. The significance of the findings was tested using bootstrap confidence intervals. The findings of the analyses revealed that neither WFC nor FWC acts as a mediator when POS is not taken into account.

Figure 3
The Moderated, Indirect Effect of Workload on Affective Commitment Through Work-To-Family Conflict with a 95% Confidence Band

Figure 4 Results of Regression Analyses for Moderated Mediation: Family-Work Conflict as Mediator
The Buffering Effect of Organizational Support VOL. 29, NO. 2, APRIL 2021 However, when different levels of POS are considered, the mediating effect of only WFC (but not FWC) was shown to be significant on medium and higher levels of POS. This implies that, even when perceiving a high workload that exacerbates their WFC, nurses with sufficiently high levels of POS may maintain a relatively high level of emotional commitment to their organizations. However, as shown before, POS did not moderate the indirect relationship between workload and AC via FWC.

Discussion
In this study, it was assumed that workload, WFC, and FWC would negatively impact AC and that this negative impact would be decreased by POS. The results support this hypothesis only partially. POS moderated the mediating effect of WFC on the relationship between workload and AC, but not moderated the mediating effect of FWC. Specifically, the results suggest that workload predicts AC negatively and WFC positively. However, POS changes the direction of the workload's effect on AC. The negative effect of workload on AC was found to be weaker for nurses with adequate support from their organizations. Accordingly, the deleterious effect of workload on AC seems to be lessened in nurses who self-perceive as being adequately supported by their organizations, which makes the buffering effect of POS a prominent factor in nurses. In addition to this buffering effect, the main effect of POS on AC is also noteworthy. The effect of POS may be explained in terms of the premises of the norm of reciprocity and social identity theory. POS seems to give nurses the feeling that the organization supports them while they are doing their jobs and coping with problems and strains. These nurses seem to reciprocate this genuine interest and support with increased commitment toward their organizations. Moreover, by fulfilling affiliation and emotional support needs (Eisenberger et al., 1986), POS may produce a strong sense of belonging, thus making organizational membership part of the self-identity of nurses. This sense of belonging seems to increase the affection of nurses toward their organization (i.e., increase AC).
As indicated before, POS may not moderate the mediating effect of FWC on the relationship between workload and AC. This finding may be explained by the conceptualization of POS. In this study, POS measures nurses' perceptions regarding whether they receive direct assistance and advice from their organizations regarding work-related responsibilities or self-development (i.e., instrumental support) and whether they are shown emphatic understanding and genuine concern for their well-being (i.e., emotional support). By improving working conditions for nurses, POS becomes more likely to alleviate conflicts arising from work (WFC), but not conflicts arising from family (FWC). In parallel with this argument, Aycan and Eskin (2005) showed that organizational support was not significantly associated with FWC and was significantly associated with WFC. In particular, the researchers revealed that organizational support is more important in reducing WFC in men, whereas spousal support is more important in reducing FWC in women. As most participants in this study were women, finding a significant moderating effect of POS on the workload-WFC and AC linkage but not on the workload-FWC and AC linkage seems reasonable. Furthermore, as the direct and indirect effects of FWC are less clear than those of WFC, future studies should focus and explore FWC and its effects on multiple outcomes.
Remarkably, the main effects of WFC and FWC on AC were found to be insignificant. This seemingly contradictory finding may be because of the characteristics of the sample. Most (70%) of the participants were employed mothers. Mothers of especially young children may regard WFC and FWC as inherent, even normal in fulfilling parent and employee roles. Expecting work-family interference as natural, nurses in this study may have found coping mechanisms allowing them to separate work and life domains, resulting in their AC being less affected by workload, WFC, and FWC. Furthermore, Casper et al. (2002) argued that, when employees experience conflict in their home or work lives, they sometimes continue to remain in their organization because they have no choice. In other words, there is a possibility that participants experiencing WFC and FWC remain with their organization out of necessity rather than choice. Therefore, we suggest researchers investigate whether WFC and FWC are associated with different forms of commitment such as a continuance or normative commitment.
Remarkably, the women nurses in this study stated that they experienced more WFC than FWC. This finding may be explained by the traditional gender roles and working conditions of nurses in Turkey. Women in Turkey are expected to fulfill their primary roles in families, and their roles in the workplace are in general regarded as secondary. As women have possibly internalized this gender role, it is reasonable to expect them to perceive less FWC and more WFC (Polat et al., 2018). Moreover, because of the shortage of nursing staff and the increasing patient population, nurses in Turkey must deal with high patient-to-nurse ratios (Organization for Economic Co-operation and Development, 2017) and heavy mental workloads (Sönmez et al., 2017). As shown in previous studies on Turkish nurses (e.g., Ekici et al., 2017;Yildirim & Aycan, 2008), heightened levels of objective and subjective workload inevitably interfere with nurses' family lives, resulting in WFC. Future studies should expand the scope of research into the potential effects of FWC and WFC.
This study is affected by several limitations. The first relates to sample characteristics. The sample was mainly composed of nurses working in public hospitals. The working schedule of nurses in private healthcare institutions may differ from the schedule of those in public institutions. Thus, our findings may not be generalizable to all nurses. The second limitation relates to sample size. Although the sample size was adequate to test the hypothesized relations using regression analysis, a larger sample size will contribute to the generalizability of findings.

The Journal of Nursing Research
Ozge TAYFUR EKMEKCI et al.
Despite these limitations, this study showed the importance of organizational support to increasing nurses' AC toward their organization. It seems that showing special consideration to the nurses' well-being and assisting them to resolve work-related problems are very important for nurses to function optimally. Supportive workplaces may be created by giving nurses opportunities to participate in decision making, being fair in the implementations of procedures, providing kindergarten services, and acknowledging their responsibilities at home. Supervisors should give sufficient consideration to the impact of workload and frequency of stressful events, which have been identified to predict WFC in nurses (Nissly, 2004). Moreover, administrators should be sensitive to working schedules that require nurses to work long hours and interfere with their family life. Offering flexibility in work schedules or at least providing nurses opportunities to voice their opinions may be viable solutions. Although it is not always possible to reduce workload, administrators may at least mitigate the negative effects of time-based conflicts by fostering supportive cultures. In other words, supervisors may provide a supportive working environment that permits flexibility in schedules, personal time off, onsite child care, or other family-supportive programs to reduce the conflicts originating from the work and home domains. In doing so, nurses may increase their emotional attachment to their organizations and thus perform better and have better physical and mental health.

Conclusions
This study investigated the mediating roles of WFC and FWC on the relationship between perceived workload and AC and explored whether these mediated relationships are affected by differing levels of POS. This study builds on previous knowledge regarding the linkages among workload, work-family interference, and AC and provides a new understanding of how organizational support alleviates the adverse effects of workload on AC. Utilizing a novel, moderated mediation model in a sample of nurses working at two public hospitals in Turkey, the results highlight the importance of POS on nurses' emotional attachment toward their organizations, making them more resilient to the detrimental effects of workload and work-to-family interference. In Turkey, a developing country with substantial problems with regard to the working conditions of nurses, the findings emphasize the importance of creating a supportive work environment to address and improve the commitment problems of healthcare employees.