DEMOGRAPHIC CHARACTERISTICS AND JOB SATISFACTION: THE MEDIATION ROLE OF ORGANISATIONAL JUSTICE PERCEPTIONS IN PUBLIC AND PRIVATE SECTOR HEALTH ORGANISATIONS IN NIGERIA

: The health sector is of critical importance to the wellbeing of the labour force, dependent demographic structure and life expectancy for economic development. Effective and efficient health care delivery is of a prime focus among stakeholders in the health sector in Nigeria. The current status of the health sector is fraught with industrial unrest and picketing following the failure of the government to meet the expectation of workers. Employee work-related attitude of job satisfaction, distributive, procedural and interactional justice perceptions of health workers in part play a key role to attaining quality health care. However, a large number of factors are responsible for job satisfaction of health professionals. In this paper, the nexus between demographics and job satisfaction is examined as well as the mediating role of organisational justice perceptions of workers in public and private healthcare institutions in Nigeria. Demographics of age, gender, education, job experience were considered with respect to overall job satisfaction and organisational justice. The study is grounded in the equity theoretical foundation of Adams in 1965. An analytical descriptive survey design was adopted in this study. A sample of 300 employees from private (150 workers) and public (150 workers) health care institutions were selected for the study through the use of a stratified random sampling procedure. The data were collected from self-report of workers via the administration of a structured questionnaire to employees. The numeric scores were determined from the summated scales of job satisfaction and organisational justice. The data were analysed with multivariate regression and structural equation modelling. From the analysed data, the study found that gender and job tenure were significant predictors of distributive justice, procedural justice and extrinsic job satisfaction while organisational justice had a significant effect on job satisfaction. In terms of the indirect effects, organisational justice mediated the relationships between gender, job tenure and overall job satisfaction. Consistent with the findings of the study, all health professionals should be treated on the basis of fairness without discrimination irrespective of status and professional dichotomy. Accordingly, the study recommended that the health care workforce who play managerial roles should ensure fairness and consider job tenure and gender in the formulation of policy frameworks for the overall job satisfaction of employees.

had significant effect on job satisfaction of employees. Andrews et al. (2008) also examined the relationship between organisational justice and job satisfaction moderated by centralisation. The findings indicated that distributive, procedural and interactional justice had stronger relationship with job satisfaction under conditions of high centralisation. Aside, Totawar and Nambudiri (2014) identified that psychological capital mediated the effect of organisational justice on job satisfaction and organisational commitment. Hooi (2012) wrote on the relationship between organisational justice, organisational citizenship behaviour and job satisfaction in manufacturing firms, and the findings indicated that organisational justice had minimal effect on organisational citizenship behaviour (OCB) while job satisfaction had a stronger relationship with OCB.
However, to date, demographic factors and organisational justice perception, and the mediation of organisational justice perception between demographic characteristics and job satisfaction have not been fully explored. Except for Sohali and Nuhu (2010) who further examined the influence of only age, rank of employees on organisational justice (OJ) and the results revealed that age and rank of employees were not significant predictors of distributive, procedural and interactional justice in Saudi Arabia. While Fernandes and Awamleh (2006) documented that age, gender and salary demographic differences had no significant influence on procedural justice. Accordingly, this article goes beyond prior studies to bridge this knowledge vacuum. The principal contribution of the study is to ascertain as to how organisational justice mediate the relationship between employee demography and overall job satisfaction. Furthermore, the influence of workforce demographics on employees' perception of organisational justice dimensions and to validate prior empirical evidence of demographic factors and job satisfaction of employees in the Nigerian context.
The broad aim of the study is to interrogate the mediating role of organisational justice perception between demographic characteristics and job satisfaction of workers in private and public sector health care organisations in Nigeria. In specific terms, the objectives of the paper are to: (1) examine the effect of demographic factors on job satisfaction of workers private and public health care institutions in Nigeria; (2) ascertain the effect of demographic characteristics on organisational justice perceptions of workers in public and private hospitals in Nigeria; (3) determine the mediation of organisational justice perception between demographic characteristics and job satisfaction of workers in public and private health care in Nigeria. The rest of the paper is structured as follows: The first section reviews literature that underpins theory and hypothesis development; second aspect explains methodology; third section presents data analysis and results; fourth section is discussion and contribution to managerial practice and the last section highlights limitations and direction for further studies.
Theory and Hypothesis development. Adams equity theoretical paradigm of 1965 that underpins the study. In the light of the equity theory of Adams, it is an explanation of the perceptions of employees in work setting as to the input-output ratio vis-a-vis fellow workers or referents in similar institution. The workers' perception of fairness or otherwise affects job satisfaction and intent to leave an organisation (Sweeney, 1990). This presupposes that the posture of the management of health institutions in the distribution of resource, application of procedures and rules, and the interaction with health care workers is essential. Accordingly, workers in health care organisations look for ways to adjust their inputs to attain a balance between their inputoutput ratio. However, the demographics of staff can as well affect the individual perception of fairness or injustice. This is the rationale to assess the influence of demographic variable on organisational justice and job satisfaction in this study.
Demographic Variables. Demographic factors have attracted the attention of scholars as determinants of employee work related attitudes of turnover intentions, job satisfaction, organisational citizenship behaviour and that such personal characteristics as well influence their perception and judgments. Demographic variables have also been acknowledged as critical to determining employee outcomes of productivity and performance. The demographic factors of age, gender, marital status, education and job tenure are capable of exerting influence on job satisfaction of employees (Santoshi, 2011;Yoganandan et al., 2022) In accordance with Santoshi (2011), assessment of employee demographics is critical to clearly understand determinants of job satisfaction and dissatisfaction, and further articulated that demographics are a set of factors which provide a definition of individual characteristics prior to employment in any entity. The scholar argues that demographic variables of workforce in any organisation are expected to be diverse, heterogeneous and accordingly differ in job satisfaction among groups. The diversity in the level of job satisfaction is an outcome of age, gender, education, marital status differentials, which influence perception and judgment towards predictors of job satisfaction.
Job Satisfaction. Job satisfaction as one of the most studied work-related attitudes in human resources management and organisational behaviour scholarship, Thiruchelvi and Supriya (2009) conceptualise job satisfaction as positive emotions, experiences and perceptions of workers emanating from assessment of one's job and job contents. Job satisfaction evaluation process of employees encompasses feelings in association with job attributes and work environments in organisations. Job satisfaction has been considered in various dimensions and facets, but the dimensions of extrinsic job satisfaction and intrinsic job satisfaction are predominant in the literature (Anleu and Mack, 2014;Calvo-Salguero et al., 2011). In the view of Calvo-Salguero et al. (2011), intrinsic dimensions of job satisfaction are the inherent characteristics of the job content, responsibility, autonomy, and variety. In contrasting with intrinsic facets of job satisfaction, extrinsic dimensions of job satisfaction are derivable from the context of performing the job, which involves salary, company policies, job security, and relationship with pears, subordinates and superiors. Anleu and Mack (2014) point out that extrinsic dimension of job satisfaction composed of pay, benefits, security and promotion while intrinsic job satisfaction includes the nature of work itself, room for initiative, work experience, human relations and affective components.
Organisational Justice Perception. Organisational members' perception of justice is salient and influences organisational behaviour and employee attitudes. Accordingly, organisational justice in regard to distribution of resources, procedures for decision making and treatment of fellow workers has attracted attention of scholars (Fernandes and Awamleh, 2006;Roch and Shanock, 2006;Karriker and Williams, 2009). Positive emotions and feelings of employees towards all factors related to work, work outcome, work itself are due to perceptions of fairness and equity. Organisational justice is conceptualised as individuals' perceptions of fairness to procedures in decision making, distribution of resources and treatments received from management in work settings (Fassina et al., 2008;Ye et al., 2022).
Drawing on the extant literature, there are three basic typology of organisational justice, which is decomposed into distributive, procedural and interactional justice. Distributive justice focuses on fairness feelings of employees over the allocation of financial and material resources of organisations (Roch and Shanock, 2006). With respect to procedural justice, it concerns with fairness judgments and perceptions of workforce in relation to adherence to accepted patterns and decision making processes leading to outcomes in organisations, and the procedures to outcomes are performance evaluation, job evaluation, promotions, and training and development opportunities to members of organisation (McFarlin and Sweeney, 1992;Lind and Tyler, 1988). Procedural justice, according to Konovsky (2000) consists of fairness with structural elements of policies, principles, rules and norms in organisations. Bies (2013) pioneered the concept of interactional justice which refers to interpersonal treatments received by organisational members in enforcing established procedures in entities. Interactional justice is the fairness perceptions of how workers are treated in organisations (Goldman, 2003;Roch and Shanock, 2006). In the view of Abekah-Nkrumah and Atinga (2013), the bases of fairness are perceived through care demonstrated, communication and the release of critical information from managers to employees and employees to other category of employees without prejudice. For the development of hypotheses, prior studies are examined in view of the study variables.
Demographic Variables and Job Satisfaction. The extant studies provide contradictory evidence in view of the age-job satisfaction relationship. Prior studies documented overwhelming empirical evidence of positive linear relationships between employee age and job satisfaction, affirming that older employees tend to have higher level of job satisfaction than younger employees. Later studies interrogated this generally upheld assumptions and findings. Subsequent studies of age and job satisfaction link reported that age does not have a linear relationship with job satisfaction but curvilinear relationships. In buttressing this argument, the study of Luthans and Thomas (1989) demonstrated a positive curvilinear association between age and job satisfaction and they further contended that supervisors at their late 30s and mid 40s were satisfied with their jobs while supervisors at their 50s experienced decline in their level of job satisfaction based on their results from a scatter plot diagram. To support the curvilinear relationship between age and job satisfaction, Clark, Oswald and Warr (1996) investigated and established U-shape relationships between age and job satisfaction with pay, work itself and overall job satisfaction using survey responses from British employees.
Gender and job satisfaction relationship has also been investigated over the decades. Bae and Kim (2016) explored the critical nature of gender with regard to impact of decoupling of telework on job satisfaction. The study used 2013 survey of federal agencies and the results indicated that female employees have the least level of job satisfaction when telework is adopted by agencies while male employees have the lowest level of job satisfaction when agencies are unable to utilise telework programmes.
In a related study with a focus on gender disparity, Miller (1980) assessed individual and occupational predictors of job satisfaction. The scholars reported that difference in specific job conditions, individual work values, nature of job and sources of gratification explained the variation in the level of job satisfaction in view of gender. Furthermore, Hunt and Saul (1975) wrote on the relationship between age, job tenure and job satisfaction in males and females. From the survey of white collar employees investigated, there was a positive linear association between job tenure and overall job satisfaction. However, a job tenure-six dimension of job satisfaction relationship was complex.
In examining the effect of educational level on job satisfaction and organisational commitment in the tourism sector, González et al. (2016) documented that educational level was not a significant predictor of job satisfaction among workers in the hospitality industry in Spain. Among other findings, they reported that influences of educational attainment is transient in consideration of job satisfaction and however stated that employees with lower level of education are disposed to express satisfaction for their jobs due to high incidence of unemployment. Fernandes and Awamleh (2006), in an expatriate environment in the United Arab Emirate (UAE), explored the impact of organisational justice on job satisfaction and performances of nationals and expatriate workers. The findings demonstrate that only distributive and interactional justice had significant effect on job satisfaction and performance of nationals of UAE but for expatriates, the three facets of distributive, procedural and interactional justice had significant effect on job satisfaction. The scholars further documented that age, gender and salary demographic differences had no significant influence on procedural justice. Following the literature reviewed. It is hypothesised that: In view of the literature reviewed, the study hypothesised as follows: H1a: Demographic factors have significant effect on extrinsic and intrinsic job satisfaction of workers in public and private health care organisations.
H1b: Demographic factors have significant effect on overall job satisfaction of workers in public and private health care organisations.
H2a: Demographic factors have significant effect on distributional, procedural and interactional Justice Perceptions of workers in public and private health care organisations.
H2b: Demographic factors have significant effect on overall organisational Justice Perceptions of workers in public and private sector health care organisations.
The mediation of organisational justice perception between demographic factors and job satisfaction. The positive feelings of employees over their job characteristics and work environment are determined by their subjective evaluation and how employees are fairly treated by management and superiors of organisations (Bhuian et al., 1996;Loher et al., 1985). The affective and cognitive feelings emanate from meeting the job expectations of employees through provision of employee outcomes by organisational entities. Besides, employer organisations are to ensure that procedures to employee outcomes and interactional processes among superiors and subordinates are in a fair and equitable manner. Further, employees in organisations have diverse socio-demographic factors of education, age gender and job tenure, which are capable to influence judgments and perceptions of workers. Accordingly, the paper goes beyond prior studies by investigating the mediating role of organisational justice perceptions of workers between demographic factors and job satisfaction. Existing studies in the current literature explored the mediating role of organisational justice perceptions between job satisfaction and other work related attitudes, which are reviewed for the hypothesis development.
In line with this, Hefferman and Dundon (2016) examined the mediating effect of organisational justice between cross-level effects of high-performance work system (HPWS) and employee well-being. The scholars reported that employee perceptions of distributive, procedural and interactional justice mediated the relationship between high-performance work system and job satisfaction, affective commitments and work pressure. In another study, Ouyang et al. (2015) explored the mediating role of organisational justice among job security between emotional intelligence and job satisfaction. The study finding demonstrated that the relationship between emotional intelligence and job satisfaction was partially mediated by organisational justice and job insecurity. Furthermore, Gelens et al. (2004) studied talent management and organisational justice in relation to employee reaction to high potential identification. The scholars reported from their study that perceptions of distributive justice fully mediated the relationship between employee identification and level of job satisfaction while perceptions of procedural justice moderated the relationship between distributive justice and work effort.
In terms of mediation of demographic characteristics between workplace, job satisfaction and performance, Abekah-Nkrumah and Atinga (2013) reported that distributive, procedural and interactional justice predicted job satisfaction and performance of health professionals, and further indicated that demographic factors partially mediated the relationship between organisational justice and job satisfaction but not performance.
Further, Elanain (2010) explored the direct and indirect relationship between organisational justice and work-outcomes in a non-Western context. The findings among others indicated that job satisfaction partially mediated the relationship between organisational justice and turn over intention, organisational commitment fully mediated the relationship between procedural justice and turnover intention. In view of the literature reviewed, the hypothesis is presented thus: H3: Organisational justice perception mediates the positive relationship between demographic factors and overall job satisfaction of workers in public and private health care organisations Methodology and research methods. Analytical descriptive survey design is adopted in this study. A sample of 300 employees from private (150 workers) and public (150 workers) health care institutions was selected for the study through the use of stratified random sampling procedure. The data were collected from self report of workers via administration of structured questionnaire to employees of public and private health care organisations in Bayelsa State in Nigeria. The questionnaire was designed on a 5 point Likert scale of strongly agree to strongly disagree with respective weights of 5 to 1for organisational justice and very satisfied to very dissatisfied with respective weights of 5 to 1for extrinsic, intrinsic and overall job satisfaction. The numeric scores were determined from the summated scales of job satisfaction and organisational justice. In respect of the demographic factors, discrete and categorical data were determined through coding of variables. From the survey of respondents, 36.3% were less than 35 years, 38% ranges between 35to 45 years while 25.7% were above 45 years of age; for gender, 45% were male as against 55% for female; with respect to marital status, 30.3% single, 52% married while 17.7% were in other category; 11% had secondary education, 62.7% for higher education while 26.3% had postgraduate education; for job tenure in years, 11.7% of them were less than 7 years, 29% ranges between 7-12 years, 41.7% between 13-18 years while 17.7% greater 18 years; for sectors of sample, 50% each from the public and private sector health care institutions. In this respect, the demographic characteristics of the sample are presented in a tabular form.
Job satisfaction is a multidimensional construct but the dimensions of extrinsic job satisfaction (EJS), intrinsic job satisfaction (IJS) and overall job satisfaction (OJS) were applied in this study. The short form of Minnesota questionnaire (MQS) of satisfaction by Weiss et al. (1967) was adopted. The dimensions of extrinsic, intrinsic and overall job satisfaction scales consisted of 6-items, 12-items and 20-items respectively. The MQS is widely applied by most scholars (Hancer and George, 2003;Callea et al., 2016) and designed in a structured 5 point Likert scale form of very satisfied (VS), satisfied (S), neutral (N), dissatisfied (D) and very dissatisfied (VD) with corresponding weights of 5 to 1. The items were scored on the basis of extrinsic, intrinsic and overall job satisfaction as explained in the manual of MQS (Weiss et al., 1967). Independent Variables. Demographic variables of age, gender, marital status, education and job tenure were considered in this study. They have been used as predictors of job satisfaction and utilised dummy codes in dichotomous and categorical forms. Age: (< 35 years=0, 35-45 years=1, >45 years= 2); Gender: (Male=0, Female=1;) Education: (Secondary Education=0, Higher Education=1, Post Graduate Education=2); Job tenure/ Experience: (< 7 years=0,7-12 years=1, 13-18 years=2, >18 year=3); Marital status: (Single=0, Married=1 and others=2); Sector: (Private=0 and Public=1).
Mediating Variable. Organisational justice perception is composed of distributive justice (DJ), procedural justice (PJ) and interactional justice (IJ) dimensions to examine the effects of demographic factors on each dimension. Apart from the facets, the overall organisational justice (OOJ) is applied as a mediating variable between demographic variables and overall job satisfaction. The measurement instrument is adopted from the scales developed by Coliquit (2001), which has been validated and utilised by scholars (Brown et al., 2010;Hashish, 2020). The distributive justice is made of 4-items, procedural justice consists of 7-items and interactional justice possesses 8-items. For the overall organisational justice composed of 19-items designed as a 5 point Likert scale of strongly agree to strongly disagree with respective weights of 5 to 1. The values applied in the analyses were through summated scales for the dimensions, the overall organisational justice and overall job satisfaction (Ary et al., 2006). Analytical Method. The data were analysed by the application of frequency and percentage distribution for demographic factors of the study. In addition, bivirate correlation matrix was presented with variables of the study demonstrating the means, standard deviations and correlation coefficients which serves as preliminary analyses. In the test of hypotheses postulated for the study, multivariate regression and structural equation modeling (SEM) were employed to determine the relationship between demographic factors and job satisfaction and organisational justice and mediation to ascertain direct effects, indirect effects and total effects. Sources: developed by the authors. Table 2 above demonstrates the correlation matrix, the mean, standard deviation values and the Cronbach alpha coefficients of the demographic factors, organisational justice dimensions and job satisfaction of employees from public and private health care institutions. Table3a displays multivariate regression analysis of demographic factors, dimension of job satisfaction and overall job satisfaction. In regard to hypothesis one (Ha1:) and hypothesis two(Ha2:), 4.2% variance in extrinsic J S, 8.8% variance in intrinsic JS and 10% variance in overall J S are accounted by demographic factors. Further, the results indicated that demographic factors all together significantly predicted extrinsic JS, intrinsic JS and overall job satisfaction respectively (F = 2.18, p < 0.05; F= 4.72, p < 0 .05; F= 5.48, p < 0.05). For the individual demographic factors and extrinsic JS from table 3b, age and job tenure are significant predictors of extrinsic JS respectively (β = -0.12, p < 0.05; β = 0.15, p < 0.05) while gender, education and marital status are not significant predictors of extrinsic JS respectively (β = -0.02, p > 0.05; β = 0.08, p > 0.05; β = 0.02, p > 0.05). With respect to intrinsic JS, gender and job tenure are significant predictors of intrinsic JS respectively (β = -0.12, p < 0.05; β = 0.01, p < 0.05) while age, education and marital status not are significant predictors of intrinsic JS respectively (β = 0.06, p > 0.05; β = 0.10, p > 0.05; β = 0.01, p > 0.05). For overall job satisfaction, gender and job tenure are significant predictors of overall JS respectively (β = -0.12, p < 0.05; β = 0.17, p < 0.05) while age, education and marital status are not significant predictors of overall JS respectively (β = 0.06, p > 0.05; β = 0.08, p > 0.05; β = 0.01, p > 0.05). Sources: developed by the authors. Table 4a displays multivariate regression analysis of demographic factors, dimension of organisational justice and overall organisational justice.
From table 5, the mediation of organisational justice between demographic factors and job satisfaction is tested, indicating the direct and indirect effects on overall job satisfaction. Considering the direct effects and standardised path coefficients, age, education, marital status have no significant effect on overall organisational justice respectively (β = 0.001, p > 0.05; β = -.084, p > 0.05; β = .066, p > 0.05) while gender and tenure had significant effect on organisational justice respectively (β = .133, p < 0.05; β = .125, p < 0.05) and organisational justice in turn had significant effect on overall job satisfaction (β = .877, p < 0.05). Examining the indirect effects and the standardised path coefficients, the results demonstrate that age, education and marital status had no significant effect on overall job satisfaction respectively (β = .001, p> 0.05, β = .074, p > 0.05; β = .058, p > 0.05) while gender and job tenure mediated the relation between organisation justice and overall job satisfaction respectively (β = .116, p < 0.05; β = .111, p < 0.05).
Below is the structural equation model (SEM) with the unstandardised path coefficients, displaying organisational justice perception mediating between employee demographics and overall job satisfaction in public and private organisations.  Sources: developed by the authors. Conclusions. The findings from the study made salient contributions to human resources management and organisational behaviour literature in organisation studies. The finding demonstrated that age and job tenure are significant predictors of distributive justice, procedural justice and extrinsic job satisfaction. This presupposes that age and job tenure influence the fairness perception of employees with respect to distribution of resources, and subjective assessment and feelings of satisfaction with extrinsic dimensions of their jobs in public and private health care entities in Nigeria. Findings concurred with the empirical evidence of Lee and Wilbur (1985) who reported that age and job tenure had significant effect on extrinsic job satisfaction.
Gender and job tenure are significant predictors of intrinsic job satisfaction while gender and job tenure are direct significant predictors of overall organisational justice.09. The finding the gender is a predictor of job satisfaction is consistent with the finding of Calvo-Salguero et al. (2011) who found that gender influenced the level of job satisfaction of both men and women, with women having higher level of job satisfaction men. The current finding further buttress the prior finding of Kavanaugh et al. (2006) who stated that job tenure (professional experience as the number of years in service) had a relationship with job satisfaction and there were differences as regards the categories of professional experiences. In terms of the indirect effects, gender mediated the relationship between organisational justice and overall job satisfaction. Also, job tenure mediated the relationship between organisational justice and overall job satisfaction. This implies that gender and job tenure have direct effect on the perception of organisational justice and in turn have effect on job satisfaction. Accordingly, health professional who play managerial roles should ensure fairness and consider job tenure and gender in the formulation of policy frameworks for the job satisfaction of employees.
Limitations and Direction for Further Studies. The study came up with critical findings but not without limitations. The study applied a cross sectional design and thus has limitations with determination of causal links between the variables investigated. Therefore, further studies can consider longitudinal design to investigate the nexus between job satisfaction and organisational justice. Also, other demographic variables can be studied, which are not included in this paper.
Conflicts of Interest: Authors declare no conflict of interest. Data Availability Statement: Not applicable. Informed Consent Statement: Not applicable.