How Does Social Support Affect Public Service Motivation of Healthcare Workers: the Mediating Effect of Job Stress

2.1. Participants

After receiving ethical approval, we conducted a cross-sectional analysis of data from healthcare workers employed in public hospitals in Beijing, Xiamen, and Guangzhou in 2017 (including doctors, nurses, medical technicians, and managers) to investigate the relationship between social support, job stress and PSM. All participants were provided informed consent.

The survey assessed individual characteristics, supervisor support, coworker support, job stress, and PSM. To ensure data integrity and objectivity, participants were selected by using random sampling according to employee number, age and job title. We selected 5–10% of healthcare workers in each target hospital. Besides, to test convergent and divergent validity in our survey, we used similar and opposite questions in the questionnaire to examine whether our respondents provide the expected answers. The participants will be deleted if their answers were not consistent. Finally, we got 973 valid participants, and the response rate was 93.8%.

Table 1 shows the demographic characteristics of the responding healthcare workers. Demographic information was missing for a few participants (range from 1.6–9.3%). Among the 973 participants, 33.5% were men and 63.8% were women; 37.2% were nurses, 32.4% were clinicians, 11.5% were medical technicians, and 11.1% were managers. With respect to age group, 29.4% were aged 25–30 years and only 1.6% were aged 55 years or older. With respect to education level, 42.2% had earned an undergraduate degree, 17.9% had earned a master's degree, 21.4% had graduated from junior college, and 4.0% had earned a doctorate. Most respondents (67.9%) had an early-career position, 11.7% had a mid-career position, and 11.1% were senior employees. Overall, 18.7% of participants had worked less than 3 years, 23.2% had worked 3–5 years, and 23.5% had worked 6–10 years.

2.2. Measures

PSM was measured with the reliable five-item scale [19]. The scale was shown to have high reliability in our research (α = 0.93). For example, the items “Meaningful public service is very important to me” and “I am often reminded by daily events about how dependent we are on one another” (Table 2) ask respondents to rate their PSM on a scale from 1 (strongly disagree) to 5 (strongly agree). Higher values indicate greater PSM.

Job stress was measured with the challenge-and hindrance-related self-reported stress (C-HSS) scale of 11 items [14]. For example, the items “The number of projects and/or assignments I have” (Table 2) and “The lack of job security I have” evaluate challenge stress and hindrance stress by using a five-point Likert scale (1 = no stress; 5 = great stress). Higher values indicate greater job stress. The C-HSS scale was shown to have high reliability (α = 0.85–0.94) in the present study.

Social support from respondents’ supervisors and coworkers was measured with the four-item “supervisor support scale” (e.g., “My supervisor takes pride in my accomplishments at work”) and the three-item “coworker support scale” (e.g. “My coworkers help me in crisis situations at work”) [20] (Table 2). Each item was rated on a five-point scale (1 = strongly disagree; 5 = strongly agree). Higher values indicate greater support. The Cronbach α values for these scales were 0.92 for supervisor support and 0.90 for coworker support, in the HRS Psychosocial Working Group, 34 and 0.92 and 0.83, respectively, for our study. Both these instruments have acceptable psychometric properties [21, 22].

The individual characteristics analyzed included age, sex, education, job title, job experience, department, and seniority.

2.3. Data Analysis

SPSS 20.0 and AMOS 20.0 were used for the statistical analyses, which comprised descriptive analysis, correlation analysis, and path analysis. Structural equation modelling (SEM) analysis was used to deal with the common-source-bias in 2 steps [23, 24], and examine relationships among supervisor support, coworker support, challenge stress, hindrance stress, and PSM that are classified as direct or indirect [25].

In SEM, five latent variables: PSM, challenge stress, hindrance stress, supervisor support and coworker support were first constructed with the items of the PSM scale, the C-HSS and social support scale. Before imputing these indicators into SEM, correlation analysis was used to determine the significance of correlations between PSM, challenge stress, hindrance stress, supervisor support and coworker support. All these indicators were examined to determine if the model fit the data well using confirmatory factor analysis.

Several recommendations have been made regarding adequate evaluation methods and sample sizes for non-normally distributed data when the normality test does not support the normality assumption for measured variables. Gold et al. insist that expectation-maximization implementation of maximum likelihood is much better than using the Asymptotically Distribution-Free Method on the model when the sample is over 500 [26]. As our study applied expectation-maximization in around 1000 participants, the method applied to evaluate model and sample size fulfilled both of these criteria.

Measures of local and global fit were checked when performing model testing. The local fit of the model was assessed on the basis of the following criteria: factor reliability values of 0.6 or more; indicator reliability value of 0.3 or more for each indicator of an underlying latent variable; p < .05 for all factor loadings and value of average proportions of indicator variance extracted 0.5 or more [27]. The criteria used to evaluate good global fit were chi-square minimal degrees of freedom (CMIN/DF < 5), a root mean square error of approximation (RMSEA) value of less than 0.05, the Goodness of Fit Index (GFI), Normed Fit Index (NFI), Comparative Fit Index (CFI) and Tucker-Lewis index (TLI) values of 0.90 or more [28]. The Sobel test was used to examine the significance of mediated effects [29].

To determine if standardized regression coefficients (β) differed by subgroup, we conducted subgroup analyses of 3 age groups, two job title groups, two sex groups, 3 post groups and 2 seniority groups. To ensure that the 5 subgroups were of equal size, age was categorized as old (41 years or older), middle (31–40 years) and young (30 years or younger). Job title was classified as early career (trainee or entry-level worker) and mid-/late career (mid-level or senior worker). Sex was categorized as male and female. The post was classified as physician, nurse and other (management and medical technicians). Seniority was classified as less than 5 years (employed for less than 5 years) and greater than 5 years (employed for longer than 5 years).

3.1. Means (SD) of PSM, Challenge Stress, Hindrance stress, Supervisor Support and Coworker Support

As shown in Table 2, the means for the 5 PSM items were very high, but the range was considerable. The means ranged from 3.40 to 4.05. The mean for the challenge stress items was higher than that for hindrance stress items. The means for the seven supervisors support and coworker support items were relatively high. They ranged from 3.39 to 3.93.

3.2. Correlations between PSM, Challenge Stress, Hindrance Stress, Supervisor Support and Coworker Support

Correlation coefficients (r) showed positive correlations between items within the same construct (Table 3). PSM was significantly positively correlated with coworker support and supervisor support (r = 0.41 to 0.53) but was significantly inversely correlated with challenge stress and hindrance stress (r = − 0.39 to − 0.45). Supervisor support and coworker support were significantly inversely correlated with challenge stress (r = − 0.16 to − 0.11) and hindrance stress (r = − 0.32 to − 0.26). There was also a significant positive correlation between coworker support and supervisor support (r = 0.60).

3.3. SEM.

Before SEM, analysis of measurement model showed that our model fits the data well, because the values for the goodness-of-fit index and comparative fit index of each measurement model were all between 0.917 and 0.952.

In the final model (Fig. 2), challenge stress (β = −0.20; p < .001) and hindrance stress (β = −0.24; p < .001) were directly inversely associated with PSM. Supervisor support was significantly positively associated with PSM (β = 0.41; p < .001), and the path from coworker support to PSM was significant (β = 0.09; p < .05). There was a direct positive association between supervisor support and coworker support (β = 0.70; p < .001). Supervisor support was significantly negatively associated with hindrance stress (β = −0.27; p < .001), and coworker support was significantly inversely associated with challenge stress (β = −0.15; p < .001). Supervisor support and coworker support explained 2% and 20% of the variability in challenge stress and hindrance stress. Supervisor support, coworker support, challenge stress and hindrance stress explained 48% of the variability in PSM.

4.1. Theoretical Implications

Our first key finding is that social support and job stress are predictors of PSM of healthcare workers, which adds to the evidence from antecedent research on PSM. Social support, especially supervisor support and coworker support, has been used to explain a wide range of individual values, attitudes and behaviors, such as affective commitment [31] and presenteeism [32]. However, very few studies have investigated the relationship between social support and PSM. Our study provides empirical evidence of the positive effects of supervisor and coworker support on PSM. However, multi-group analysis showed that the impact of coworker support on PSM is weaker than that of supervisor support.

Challenge stress and hindrance stress had a significantly direct negative effect on PSM of healthcare workers, which differs in part from our previous hypothesis and research findings. Previous studies reported that challenge stress has a positive effect on individuals, e.g., by encouraging workers to learn and to overcome obstacles, thus benefiting career development [14, 33]. We assumed that challenge stress was positively related to PSM; however, the present findings show that challenge stress has a significant negative effect on PSM and that the effect is as strong as that of hindrance stress. This interesting finding might be due to the complex working environment for healthcare workers. To our knowledge, the workload of healthcare workers in China is heavy: many are pressured to work 10 or more hours almost every day and always with high efficiency and in a state of tension [34].

Although no studies have examined the relationship between hindrance stress and PSM, the adverse effects of job stress, especially hindrance stress, on the individual and organization have been widely discussed in many studies based on JD-R theory. These effects include burnout [35], increased presenteeism [33], and increased turnover intention [36]. Hindrance stress includes demands that are viewed by managers as unnecessary impediments to personal growth and goal attainment, and by employees as insurmountable [14]. The present analysis of data from 973 healthcare workers employed in Chinese public hospitals provides direct evidence of the negative effect of hindrance stress on PSM.

Our findings show that supervisor support and coworker support had significant negative effects on hindrance stress and challenge stress of healthcare workers, respectively, which supports our previous hypotheses. The relationship between social support and job stress is multipath [37]. Previous studies often investigated social support and job stress in the same research model but failed to explain either how social support affects job stress or the differential effects of supervisor support and coworker support. Consequently, to complement these previous findings, we investigated separately the relationships between supervisor support and hindrance stress, and between coworker support and challenge stress. Our results suggest that supervisor support lessens the hindrance stress of healthcare workers, because they feel they are taken seriously by their supervisors and that the work environment is fair.

Another important finding of this study is that while hindrance stress and challenge stress directly affected PSM, hindrance stress also mediated the effects of supervisor support, and challenge stress mediated the effects of coworker support, on PSM. Because of the limited data on the antecedents of PSM, previous studies did not consider mediators between social support and PSM. Our results shed light on how supervisor and coworker support affect PSM through hindrance stress and challenge stress, as described in JD-R theory. Hindrance stress and challenge stress are the individual's psychological reactions to job demands. Supervisor support and coworker support are important organizational resources provided to workers and help workers to meet their work demands, while reducing job stress and increasing PSM.

4.2. Implications for Management

Our findings have a number of important practical implications for managers of public hospitals who hope to reduce job stress and promote PSM among healthcare workers and improve healthcare quality.

Firstly, managers of public hospitals should be mindful of the intense job stress of healthcare workers and undertake interventions targeting challenge stress and hindrance stress. Challenge stress can be managed by ensuring reasonable workloads, rational shift arrangements, and appropriate time pressure and by balancing worker rights and responsibilities. Hindrance stress can be improved by developing a fair organizational climate, scientific performance assessment standards, clear job responsibilities, and a concrete employee growth scheme [38]. In addition, public hospitals should consider interventions that help relieve employee job stress, such as psychological counselling, physical exercise, recreational activities, and lectures on mental health.

Secondly, public hospital managers should encourage and assist supervisors in their leadership functions, e.g., by urging supervisors to (1) care about the work and life of subordinates and assist them whenever possible, (2) identify and acknowledge the strengths and accomplishments of workers and encourage and recognize their efforts, and (3) make workers' jobs as interesting as possible [39]. Public hospitals should develop training courses for supervisors, on topics such as leadership, strategic management, and communication management.

Thirdly, managers of public hospitals should emphasize coworker support and good employee relationships. For instance, a system of group activities in public hospitals could be developed in order to enhance coworker support. Such a system could include training activities and outward-bound activities and might prevent conflicts and improve career development.

4.3. Limitations and Future Research

This study is not without limitations. Firstly, the study was cross-sectional. Thus, the relationships between social support, job stress and PSM cannot be assumed to be causal and should be further examined in a cohort in a future longitudinal study. Secondly, we only recruited healthcare workers from Chinese public hospitals and excluded those from private hospitals, which limits the generalizability and robustness of our conclusions. Social support, job stress and PSM differ somewhat between public sector and private sector employees [40]. Therefore, to verify our hypotheses and models, future studies should investigate healthcare workers from private hospitals. Thirdly, our study considered only the effects of work-related dimensions of social support, which were mostly limited to job stress and PSM. Although the scale including supervisor support and coworker support dimensions could be used to adequately test social support, other dimensions of social support might be important in job stress and PSM. Future studies should examine how the support of family, friends and spouses affects job stress and PSM of healthcare workers. Fourthly, our study want to explain the potential psychological process of employees working in public sectors under the combined effect of job demands and job resources. However, JD-R theory proposed that social support and job stress not only affect employees’ motivation, but also significantly affect their burnout and job performance. On the basis of the results of the current study, future studies should integrate more psychological outcome variables in our research model. Finally, our sample comprises healthcare workers in a developing East Asian country and does not include healthcare workers from countries with other cultures and different levels of development. Future studies should examine whether the present findings are consistent across cultures and stages of economic development.