Nurses' Work Motivation and the Factors Affecting It: A Scoping Review

Objective: This review is aimed to examine nurses’ work motivation and factors affecting it. Methodology: Cochrane library, MEDLINE, PubMed, Science Direct, Cumulative Index Nursing and Allied Health Literature (CINAHL), ProQuest and Ovid databases were searched, covering the period 2011 to 2017. Studies were included if they concerned nurses’ work motivation and the factors affecting it. Results: In the yielded studies, nurses’ work motivation is affected by several personal and organisational factors. Nurses’ age, years of experience, autonomy, educational level and administrative positions were found as personal characteristics that affect nurses’ work motivation level. Moreover, nurses' empowerment, work engagement, pay and financial benefits, supervision, promotion, contingent rewards, supportive relationship (co-workers), communication and nature of work were identified in the literature as organizational factors affecting nurses’ work motivation. Conclusion: This review confirmed that nurses' work motivation was often affected by several personal and organizational factors which are crucial in affecting the level of nurses' work motivation. Nurses' Work Motivation and the Factors Affecting It: A Scoping Review Publication History: Received: April 01, 2018 Accepted: April 23, 2018 Published: April 25, 2018


Introduction
In healthcare organization, work motivation is an important measure of healthcare professional's response to the increasing challenges and demands [1]. Motivation is known as a process that starts with an inspiration to perform and energized to an end [2]. It initiates behaviours to accomplish the intended goals. Motivation is a complex, multidimensional and therefore defined as "the force within individual that influence or direct behaviour" [3]. Motivation is a concept used to describe an external state inspiring a special behavior and internal responses revealing that behaviour [4]. In the organizational context, motivation is explained as the stimulus of work behaviour, which channels the worker's effort to accomplish the organization's goals [5]. Worker motivation is the result of the interactions between individuals (internal psychological process), their work environment (a transactional process) and the fit between these interactions and the societal context [6].
There are two different types of motivation: intrinsic and extrinsic. Intrinsic motivation (IM) is an inner force that leads workers to meet personal and organizational aims [7]. It guides individuals to do activity that they find it exciting [8]. People who were intrinsically motivated have internal drive that forms behaviors and inspiration to perform responsibilities without any external effects. Therefore, IM arises from the person's pleasure in the job itself or self-interest and without pressure of others as well as it is recognized by its own and does not rely on results. IM among nurses, in the healthcare context, is operationally defined as self-gratification and pleasure in carrying out responsibilities instead of working for external rewards [7].
Extrinsic motivation (EM) is an exterior force that leads workers to meet personal and organizational aims [7]. Moreover, it guides persons to carry out responsibilities by using coercion or instruction to get rewards in return [8]. Extrinsic rewards consist of awards, bonuses, pay and benefits [9]. It also can be in the forms of good relationship between workers, better facilities, good working conditions and higher administrator's quality at the work area [10]. EM in the healthcare context leads the nurses to achieve work behaviors such

Search terms
The search started by dividing the review aims into two parts to facilitate an easier and more importantly a more accurate search process. Thus, the definitive search terms used in this study were: 1. Nurses' work motivation: nursing, nurses, work motivation, self-determination theory, intrinsic motivation, extrinsic motivation, job motivation.

2.
Factors affecting nurses' work motivation: motivation factors, motivation questionnaire, motivating factors. To illustrate how these terms were used, the search commenced with each keyword, and was further developed by grouping and combining terms together by using Boolean operators to broaden or narrow the combined key words or phrases by using AND and OR across all databases.

Literature search results
Using these keywords targeting each database resulted in a large number of hits. The number of hits identified is shown in figure 1.

Synthesis of evidence
A broad range of studies focusing on different aspects of work motivation related to nurses were identified as a part of the literature search. Each study included was reviewed individually by comparing each paper's aims and/or objectives, study design, data collection and analysis methods, conclusion of the study findings and implications for practice. Int

Nurses' motivation and work outcomes
Nurses' work motivation has an impact on wellbeing, organizational performance, satisfaction, retention, engagement and commitment [11,12]. With regards to wellbeing, feel of happiness is known as an advanced psychological experience of individuals [13]. Individuals who were intrinsically motivated found that job itself is interesting, challenging and fun [7]. Happiness and wellbeing of workers themselves depends mainly on their motivation level, organizational or personal sources of happiness at work [14]. In a quantitative study conducted among nurses in China to examine the factors that contributed to nurses' happiness index indicated that happiness affected by positive emotions and stress managing styles [13]. Consequently, the study suggested that managers in the healthcare setting should provide active psychological counselling and care to promote nurses' enthusiasm and inspire their commitment to improve happiness level of nurses.
However, highly externally motivated workers are usually more interested toward the fulfilment of basic human drives and needs than the work itself; thus, workers were likely to set the minimum amount of energy at job to attain the instrumental goals, without getting any happiness or IM from performing their work [15]. Thus, such persistent dissatisfaction with work characteristics and conditions may lead to decrease in the level of the nurse's commitment and motivation and increase in turnover rate [16,17]. It is therefore important to first implement external motivator strategy to meet physiological or safety needs (the lower order needs) of the staff then apply incentive systems for IM such as by satisfying higher order needs (i.e. achievement and self-actualization) [18].
The association between burnout and motivation was also highlighted in the literature. The term burnout is used in order to define the state of physical, emotional and mental fatigue resulted from long-term participation in work conditions that are emotionally demanding [19]. A study examined the motivational correlates of work holism, work engagement and burnout showed that burnout is negatively associated with IM and autonomous EM (i.e. identified regulation) as burned-out workers do not experience their work activities as exciting, satisfying or pleasurable and do not identify with their instrumental value or their work activities. The study suggested that encouragement of autonomous motivation may immediately lead to an increase in work engagement and a decrease in work holism and burnout [20]. In a further study conducted in Canada among nurses, the results showed that autonomous motivation were negatively related to burnout and positively related to commitment and work performance [21].
Role of motivation on work outcomes in nursing was examined in several studies. A cross-sectional study conducted among hospital nurses in Italy to examine the mediating role of motivation on the association between organizational factors and work outcomes reinforced the importance of the mediating role of autonomous motivation on the relationship between both perceived organizational support and job autonomy and positive work outcomes such as high level of affective attachment to the organization, high job satisfaction and low levels of intention to leave [22]. Furthermore, a study surveyed 572 French-Canadian newly registered nurses to assess whether different motivation forms (autonomous vs controlled) predict intention to quit the occupation and organization through different forms of commitment. The results showed that autonomous motivation negatively predicts intention to quit the occupation and organization through target-specific affective commitment while controlled motivation positively predict intention to quit the profession and organization [23]. Similar results were found in a study carried out to provide insight into the difference relationships between job characteristics (job demands and resources) and employee functioning by investigating the psychological and motivational processes involved among 699 Canadian nurses [24]. The results demonstrated that positively estimating need was satisfaction and negatively estimating need was frustration while job resources fostered optimal work motivation (more autonomous and less controlled motivation) and employee functioning [24].
Whereas motivation directs and stimulates employee actions at hospital [15], the level of motivation regulates nurses' commitment and performance in nursing practice [16]. A study was conducted in Italy to investigate the relationship between motivation and commitment mind sets and their impact to work outcomes [16]. In this study, authors surveyed 487 nurses from a hospital in the centres of Italy as well as 593 nurses from a hospital in the north of Italy. Results presented that commitment was related to work motivation which were significant antecedents of workers' behaviors and attitudes. Additionally, self-determined motivation had an important mediating role in positive behaviors [16].
Organizational commitment is an important aspect related to work motivation [16]. A study assessed organizational commitment and job motivation among nurses in Iran indicated that both commitment and motivation are multidimensional and may vary by individual and organizational characters [25]. In a further study the results showed that IM was positively related to commitment which in turn is negatively related to intention to leave [17].
In regard to job satisfaction, a positive relationship was found between self-determined work motivation and nurses' job satisfaction [16]. This relationship and its effect on turnover intention was examined in Ghana. The study represented that motivation and job satisfaction were both significantly associated with turnover intention, indicating that health employees with higher levels of work motivation and job satisfaction were less likely to having intentions to quit their current health organization [26]. However, in a further descriptive study in Turkey, the results demonstrated that there is no statistically significant difference between general satisfaction scores and total motivation scores [27]. Similarly, in India a surveyed study found that there is no association between IM and job satisfaction factors among primary health care providers. This means if healthcare providers are satisfied in the organization it does not mean that they will be motivated also [28].
Work motivation is critical for health worker's performance [29]. Work motivation has been found to influence work performance and the outcomes of work in health care in several studies conducted in different healthcare organisations. For instance, in a quantitative study aimed to examine the relationship between motivation and performance among nurses working at European Gaza Hospital indicated that highly motivated nurses achieved better performance outcome than low motivated nurses. This result raised the need of training and equitable work schedule to enhance motivation and reinforce performance [30].
Furthermore, by using Herzberg's Two Factor theory to provide a conceptual analysis of motivation and job performance of nurses in a private hospital in Malaysia, this study reported that both IM and EM were positively related to nurses' job performance [31]. Whereas, another conducted study in Malaysia found that IM is positively related to nurses' job performance by surveying nurses working in health tourism hospital [7]. Consequently, IM cannot be underestimated as an important effect in improving nurses' performance as well as nurses have started to turn to intrinsic rewards instead of extrinsic rewards by understanding their actual needs in the organization [7]. Additionally, a mixed-method study design in the primary care facilities in Ghana was conducted to determine the impact of performance-based incentives on motivation of maternal health worker [32]. This study found that performance-based incentives were associated with a little improvement in healthcare worker's motivation [32]. Therefore, to improve nurses' performance there is a need for intrinsic rewards such as autonomy, growth, feedback and recognition that create a sense of achievement, ownership and satisfaction [7].
Additionally, nurses' work motivation and quality of patient care were also examined in several studies. One of the studies suggested that a higher levels of nurses' work motivation is associated with higher levels of providing patient centred care [33]. In this study, the researchers surveyed nurses who were working with older individuals in various health care settings including hospital, long-term care, and the community in Finland [33]. Moreover, a study conducted in the Netherlands by distributing surveys among nurses working with dementia patients in 37 long-term-care and residential settings as well as by observing nurses' work behaviour. The analysis showed that nurses had the highest levels of work motivation by smiling and initiated friendly conversations more frequently with residents [34].
In Ghana, a study was carried out to address the indicators of health employee motivation and assess the associations between quality of care and patient safety. This study indicated a positive correlation between staff motivation level, patient safety and quality improvement suggesting that there is a need to assimilate motivation strategies into healthcare facilities quality improvement plans [35]. Similarly, in Estonia, 201 nurses were surveyed at many hospitals to determine their perceptions and the relationship between these perceptions of workplace characteristics, working conditions, work motivation and patient safety. The results suggested that perceptions of individual control over their work can affect nurses' motivation, and that perceptions of work satisfaction might be related to patient safety enhancement work [36]. Hence, nurses motivated in their work (who experienced more empowerment, engagement, autonomy) significantly had more self-reported patient safety events a year (P<0.001) [36]. Furthermore, a systematic review was conducted on trust and motivation in the health sector indicated that workplace trust relationships among health workers have an impact on their IM and have consequences for performance, quality of care and retention [37]. Well highly motivated and appropriately qualified healthcare provider is significant to the success of providing high quality of care [19].

Factors affecting nurses' work motivation Personal Factors
Personal characteristics such as age, gender, marital status, education level etc. were highlighted as personal factors affecting nurses' motivation in nursing literature. Sociodemographic variables were found to be important predictors that clarify the changeability in the IM factor score [38]. For instance, a quantitative study conducted in Iran, the results showed that that age, gender, academic degree, years of experience and marital status were important variables that affect motivation factors [39].

Age
Nurses' age was highlighted in the literature as a personal factor affecting work motivation. For example, a cross-sectional study to examine the relationship between reward and nurses' motivation in Ethiopia demonstrated that there was a significant difference in nurses' work motivation based on age [40]. A further mixed method study conducted to determine healthcare professionals' motivation level and factors affecting it in three hospitals in Ethiopia found that there was a significant correlation between age and motivation level [41]. In contrast to the latter, a mixed method study conducted in Tanzania among healthcare workers revealed that there was no significant difference in the motivation according to health workers' age and qualification [42]. Similarly, a quantitative study conducted in Punjab reported that there was no statistical difference in the motivational level based on the age of the employees [43].
Older nurses seem to give additional value on achieved selfactualization, autonomy and self-direction [18,44]. This is due to the reason that they gaining higher level of education, more experience and longer duration of service [12]. They also develop more self-assured and experienced which have been found to increase motivation of nurses [18,44]. Younger nurses appeared to get more motivation and enthusiasm through their relations with clients and their families and have conveyed that patients' safety and their safety as being the utmost essential factor to them at job [45]. A qualitative study in Canada examined the experience of novice nurses with a particular emphasis on the quality of work life concerns during the transitional phase [46]. The results showed that novice nurses were highly motivated to deliver quality of patient care but possess feeling of self-doubting and suffering from stress because of their perceived underestimation by experienced coworkers and from their lack of experience in nursing [46]. In addition, a mixed method study conducted in New Zealand examined what factors generation Y registered nurses desire to change about nursing [47]. The changes that participants would have liked to get were better work-life balance, more autonomy, improving in work condition (increasing nursing staff and personal support), increase salary, recognition and appreciation from old generation, improvement the relationship with supervisors, and the need for nursing to be less stressful, more promotion and growth opportunities [47].
Difference of work motivation based on nurses' age (younger and older nurses) was also examined in several studies. For example, in Greece, a study conducted to investigate work-related factors and demographic variables to predict motivation this result suggested that nurses' age is significantly associated with motivational factors [18]. Moreover, this result showed that younger nurses with postgraduate education appeared to be more motivated for job attributes, coworkers and achievement while older nurses motivated mainly by remuneration [18]. Additionally, in Finland a quantitative study revealed that older and more experienced nurses tended to desire financial reward compared to younger nurses [48]. Similarly, older nurses with a high position or a longer duration of service had higher EM and tend to desire incentives and recognition more than younger nurses [12,18,30].
In addition, a quantitative study in Ghana surveyed healthcare workers to examine the role of non-financial incentives on their motivation demonstrated that younger employees were much motivated by training and career development as well as staff accommodation whereas, older employees were motivated by recognition, praise and acknowledgement [49]. Meanwhile, a crosssectional study to determine motivating factors in front line employees at teaching hospitals in Iran. The results found that motivation of employees under 30 years of age were more affected by job content, autonomy and social respect than in employees over 30 years of age (p < 0.05) [50]. Moreover, in India, by surveying healthcare providers in a quantitative study, the results showed that older employees were more motivated than younger employees as well as the study revealed that in different age groups there was no significant difference for intrinsic motivation [28].
Unlike the previous findings, age was found to be a negative predictor of the IM in a study which demonstrated that when the age of participants increased by 1 year, the IM was lowered by 0.116 units [38].

Gender and social status
Gender and social status were also found in the literature as factors affecting nurses' work motivation. For instance, a qualitative study investigated how social factors impact on health workers' motivation and performance showed that different gender and marital status may have an effect on nurses' motivation [51]. In this study, most female respondents (20 of the 22) indicated that family factors such as being a wife and mother, husband's place of work, parental pressure and health of family members and children's schooling interrupted on their motivation and work performance [51]. In addition, a crosssectional survey study identified factors affecting health workers' motivation in Iran found that monetary incentives was significantly more motivating for divorced and singles compared to the married employees (p=0.036) [52]. In a further cross-sectional study measured three aspects of motivation (management, performance and individual) among health workers in primary level health facilities in Tanzania. Researchers found that workers with no dependents had the lowest motivation score (p=0.002) [53].
However, few studies claimed that male nurses were more motivated by rewards, morale, recognition, supervision and management, and communication [30] while female nurses were more motivated by non-fiscal rewards [48]. Nevertheless, in a further study, the results showed that female employees seem to give more importance to remuneration than male as motivating factors (p<0.001) [50]. Furthermore, a descriptive study conducted in Ghana found that most male healthcare workers were motivated by training and career development in contrast to most female healthcare workers who were highly motivated by recognition, praise and acknowledgement than the male respondents [49]. Furthermore, motivation level were significantly higher in male employees than female employees [30,43]. Unlikely, males respondents had lower IM score compared to female respondents [38]. Similarly, in a quantitative study conducted among health workers in Zambia found that female respondents had the highest motivation score than male [54].
However, four quantitative studies found that there were no statistical significant differences between gender and motivation among hospital nurses working in Greece, India, Ethiopia and Turkey [18,28,40,55] respectively. Nevertheless, in a further study, the results highlighted that there were unclear associations between nurses' gender and motivation as usually the group of male respondents being too small comparing with the group of female respondents in nursing studies [15].

Education qualification
A significant difference in nurses' work motivation based on educational qualification was reported in the literature [40]. Employees possess academic degrees assigned more importance to career development and job content (p = 0.04). In contrast, employees have less education allocated more importance to remuneration, autonomy, social respect and working relationships (p < 0.05) [50]. Moreover, a study conducted in Ethiopia demonstrated that health professionals with higher degree of education (master's and doctors' degree) had the highest mean motivation scores [41]. Likewise, there was a statistically significant difference in IM for education level; additionally, undergraduates' healthcare providers reported that they were less motivated than graduates' healthcare providers [28].

Managerial position/ authority
Several studies highlighted that holding managerial positions can motivate nurses. For example, a study conducted amongst health employees working in a Tertiary care Government Hospital in India revealed that the first rank among motivational components for nurses were control domain (which include power, position/grade, hiring to follow professional and standards of ethics) [56]. Likewise, a further study revealed that having an authority can motivate the healthcare workers [57]. Similarly, further study showed that nurses' managers (nurses in the leading position) were more motivated than nurses staff [18]. Furthermore, nurse's managers were more motivated by communication, morale, recognition, rewards [30]. Similar result was demonstrated in two studies indicated that status and authority were the most important factors contributing to nurses' work motivation [45,58]. However, no statistical significant differences were found in the perception regarding motivational factors between the professional position groups [45].

Years of experience
Number of years in the current profession was associated with motivation [53]. This was revealed in a study demonstrated that there were significant differences in motivation related to years of experience [40]. Another study highlighted a similar result that nurses with years of experience above 5 years desired recognition and rewards [18,30]. In addition, more experienced employees' desired remuneration, recognition and autonomy [50]. However, this study also showed that staffs with job experience less than 10 years attached more importance to career development, job content, and social respect (p<0.05) [50]. Furthermore, with high years of experience or very high self-rated expertise, nurses' work motivation sharply increased [44]. Similarly, nurses with longer duration of service, better experience and knowledge about their work increased their work motivation level [15,54].
In contrast to the previous studies, no statistical significant difference in motivational level based on duration of service was found in another study [43]. However, a study conducted among nurses / midwives in Turkey found that as the number of work year's increase, job satisfaction and motivation decrease which can be explained by increasing responsibilities in family life and inability to get the necessary satisfaction and motivation from work [27]. Furthermore, in a further study found that motivational factors such as rewards, status and authority, independent study, counselling, promotion opportunities and physical environment are higher in nurses with less than 5 years of duration of service [45].

Organizational Factors Empowerment
Nurses' empowerment and good patient safety outcomes were highlighted in the literature as an organizational factors that can increase nurses' motivation level [30,36]. For instance, a quantitative study carried out among hospital nurses working in central China to test the Job Characteristics Model and the mediating role of structural empowerment on the relationships between the job characteristics and work-related outcomes indicated that a sense of empowerment contributed to internal work motivation [59]. Moreover, in another study the results suggested that the organizational setting must be supportive and empower nurses to respond to the organization requirement [25].

Autonomy
The providing autonomy to nurses was found to be related to higher levels of work motivation in several studies [60]. For example, by surveying hospital nurses in Estonia, the results found that there was a positive relationship between the existence of autonomy and work motivation [15]. A similar result was found in another study conducted in China who surveyed nurses working in acute care setting [59]. Likewise, in a study carried out among nurses in Italy showed that there was a positive relationship between job autonomy and intrinsic work motivation which is negatively related to turnover intention [17]. Additionally, by surveying nurses to study the affecting factors on work motivation in many hospitals in Iran, the author concluded that the participation of the nurses in making decision are important motivating factors in the healthcare organization [61].

Engagement
Nurses' work engagement was highlighted in nursing literature as an organisational factor which can increase the level of nurses' work motivation [15,59]. In China, a study revealed that work engagement is positively associated with both intrinsic motivation and extrinsic motivation [20].

Supervision and management
Unsupportive supervision was reported as a demotivating factor [62]. Moreover, supervision and management were found as factors that can motivate a total of 14% of nurses to work at the hospital [10].Furthermore, positive environment and supportive supervision are important motivation strategies that should be considered by all managers [42]. Supervision and leadership provided by the officer in charge appeared to have a positive effect on motivation [29].A study carried out to identify the factors affecting health workers motivation revealed that good management was the most important motivator for health employees followed by the support during problems and fairness from managers and supervisors [52].Furthermore, supervision is affecting healthcare worker's motivation level [41] Moreover, supervisors' support was found to be important motivating factor [57]. Similarly, in a qualitative study conducted among healthcare workers in Nigeria suggested that employees are motivated by problem solving leadership, staff dynamics and supervision [29].
However, weaknesses and difficulties in the management were revealed as demotivating factors [63]. Healthcare organizations are encouraged to enhance transformational leadership and other positive managerial practices to promote motivation and high quality of care among health care employees [21,24]. Thus, decentralized structures associated with nurses' work motivation [10].

Supportive relationship and communication
Supportive relationship in the workplace that valued effective communication was found to be linked with an increase of nurses' work motivation [60]. In Iran, a study reported that social respect and working relationships were highlighted as organisational factors affecting work motivation [50]. Furthermore, by surveying hospital nurses in Estonia, it was found that the feeling of being a member in an effective team, and the existence of respectful relationship was associated with an increase of nurses' work motivation [15]. In addition, functional teamwork increased intrinsic work motivation only [15]. Similar result was demonstrated in a study which found that the interpersonal relationships and respect at work was associated with the increased work motivation [18]. Likewise, in Iran, work motivation is affected by good co-workers' relationships [52]. Receiving good partner support motivates healthcare workers [63]. Motivation of health care workers can be affected by conflict between collaborating workers such as doctor and nurses which will affect hospital's goal of providing high quality of health care to clients [64]. Furthermore, polite communications and feedback, trust relationship with co-workers, administration and clients [37] have been reported to increase motivation level of nurses in several studies [18,20,56]. Moreover, in the health care organizations, effective communications increase the motivation level [38]. In addition, in a study conducted among maternal healthcare workers revealed that respect from the community and good interpersonal relations were found as motivating factors while distrust from clients was found as demotivating factors [62]. Additionally, in a study conducted in Cairo to identify factors affecting their work motivation in two hospitals, the results showed that the respectable relationship within the hospital, teamwork among nurses, work environment free from tension as the highest motivating factors [65].

Nature of work
Several organisational factors motivating and demotivating professional performance of nurses in the healthcare organisation. However, clear job description, nurses' patient ratio and the availability of nursing aids were reported as the lowest mean score as a motivating factor among nurses [65]. Recently, in Tanzania, a study demonstrated that a clear job description was an important motivating factor in both management and performance aspect [53]. Providing clear roles and responsibilities as well as the appropriateness of tasks with the nursing profession were all reported as important motivating factors in the healthcare organization [57,61].

Career development, professional training and learning opportunity
A positive relationship was found between health workers' motivation and education opportunity [53]. Exposure to suitable educational programs under the supervision of experienced nurse manger may support the development of nurses' motivation [25]. Furthermore, among the motivating factors, career development had the highest ability to motivate nurses in their job [58].
Several studies found that there was a relationship between training and work motivation [60]. A quantitative study surveyed nurses in Rwanda revealed that two third of the respondents believed that education, training and professional development could increase work motivation level [10]. Among nurses working in Estonia's hospitals, study reported that those nurses who had at least 8 days of effective inservices training in the previous 12 months had higher levels of work motivation [12]. Similarly, in a study conducted in Zambia, health employees who had some form of professional training related to their work in the prior year had higher levels of work motivation [54]. Additionally, a mix method study in Vietnam to identify contextual and organizational factors affecting motivation of maternal health workers. The results indicated that access to relevant-work training and ability to do the main task were main factors affecting motivation [62]. However, motivation was lower among health workers who had received training irrelevant to their work in the last year or those who do not have the chance to perform their learnt skills [62].
In an exploratory study, maternal and newborn healthcare providers and managers were interviewed in Tanzania in order to examine the influences on work motivation, performance and satisfaction and found that the key sources of encouragement for all the types of participants was on-the-job learning [63]. Furthermore, among all motivating factors, nurses ranked in-service training as the highest one as it improves self-confidence, self-esteem and increases opportunities for promotion [30]. Additionally, among health workers, 80% were highly motivated by training and career development [49]. Also, upgrading, training, seminars and children education were important motivating factors among healthcare workers [42]. Furthermore, perception of underprivileged work achievements and inability of providing a high-quality service as well as ineffective training opportunities were reported as demotivating factors [62]. In contrast to the above, a further study indicated that continuing education had the minimum effects on motivating the study population [52].

Contingent rewards
Contingent rewards is known as recognition, appreciation and rewards were found as motivating factors which can increase nurses' work motivation [10,56,66,67]. Moreover, community recognition and appreciation was also found as a motivating factor among healthcare workers [29,63].
Rewards and nurses' work motivation are directly and positivity associated [25]. Majority of nurses (83%) agreed that a reward system could promote nurses' work motivation [10]. Moreover, a further study demonstrated that non-financial rewards such as recognition, job security and using various skills have been reported as an important motivator [48]. Furthermore, rewards such as performance evaluation and management, leadership skill and supervision was found to be strong predictors of health employee motivation [38,67]. On the other hand, lack of appreciation, rewards for good job and recognition lead to a low level of work motivation [40].

Pay and financial benefits
Financial incentives were highlighted in the literature as a motivating factor that advances nurses' work motivation. A positive association was found between motivation score and salary scale [53]. Remuneration was also found as an important motivating factor among healthcare workers in a study conducted in Nigeria [29]. In Rwanda, the principal motivating factors mentioned by nurses were remuneration and pay as more than half of nurses agreed that increasing salary could promote nurses' work motivation [10]. Likewise, in a study conducted in Cairo reported that nurses perceived pay and fringe benefit (periodical medical check-up, meal for nurses) as an essential motivating factor [65]. In Ghana, a study examined the financial and non-financial factors influencing the retention and motivation of health workers in the quantitative study. The results found that financial incentives such as salary, adequate remuneration, compensation for working in remote district hospitals and benefits significantly influenced motivation as well as retention [67]. Moreover, a cross-sectional survey examined staff stability and health workers' motivation in four rural districts in Tanzania, results found that public organisations continued to be very attractive with well salary and retirement benefits. Thus, this study concluded that motivation strategies should focus on satisfactory remuneration [42]. Financial rewards (such as better salary) have been reported as important motivators [48,61]. In addition, by investigating the factors influencing motivation and retention among health care workers in a mixed-method study design in Kenya, the results indicated that the salary and remuneration were found statistically significant factors affecting work motivation [68]. A similar result was demonstrated in a study conducted among nurses in Pakistan which found that financial incentives were found to be the most important motivating factor for nurses that improve their performance [66]. Furthermore, salary and other monetary benefits were the most important motivating factors among healthcare workers in India [57].
In contrast to the previous studies, a cross-sectional study conducted to investigate the factors and level of motivation amongst staffs working in India in tertiary health care facilities revealed that the first rank among motivational components for nurses were control domain (such as power and position) followed by relationship domain (teamwork) and third rank for rewards domain (such as pay and growth) [56]. However, remuneration had the least influence on the work motivation of frontline employees [50].
Financial benefits are associated with healthcare workers' motivation [41,52]. Although financial rewards are a great source of health worker motivation, non-financial incentives (e.g. the working environment, training and career development, job security, promotion, growth and development, recognition, praise and acknowledgement, and staff accommodation) were very important source of health worker motivation [49]. Income and financial allowance [52] have been reported to be important motivators which able to fulfil various individual needs [45,48]. Insufficient amounts of payment and allowances would lead to low level work motivation [40]. However, low income levels and inconsistent in the payment of leave and overtime were recognised as demotivating factors [63]. Moreover, further demotivating factors in the organizational level include lack of allowances, inadequate remuneration and unequal salary structure [29].

Promotion opportunities
Promotion was found to be strong predictors of health employee motivation [38,67]. The achievement-related promotion was reported to be the most important motivation factors [57]. Similarly promotion was very important source of health worker motivation [49]. Moreover, lack of promotions or malfunction of the promotion system was considered as demotivating factors among nurses as well as other healthcare workers [42,63].

Equity and Organizational justice
Equity was reported as nurses' priority of motivational factors [39]. Organizational justice denotes to the perception of equality in the work setting [39]. In a study aimed to examine the impact of many types of organizational justice which includes procedural justice (is the perceived fairness of processes), interpersonal justice (is the perceived fairness of treatment of workers), and distributive justice (is the perceived fairness of how results are disseminated) on work motivation in health care organizations in Canada, this study found that work motivation is primarily affected by interpersonal and procedural justice, and that distributive justice has little impact [69]. Furthermore, the study concluded that in order to motivate health care workers, it is required to focus on organizational justice (procedural and interpersonal forms) particularly [69].

Working conditions
Working conditions in health care organization incorporate supportive organizational system, flexibility in working hours, satisfactory human and material resources, staffing, sharing job,changing shifts and parental leave, safe and healthy environment, transportation services, supportive operating policies and procedures, effective capacity management and remuneration and allowances were related with nurses' work motivation [10,15].
Adequate staffing and fixed schedule were considered as important motivating factors in nursing literature [20,30,51]. For instance, adequate staffing, good support structures, and the opportunity for sharing the job with co-workers increased nurses' IM, while chances for flexible work hours (such as parent leave and changing shifts) were associated with nurses' EM only which particularly increased introjected regulation of extrinsic work motivation [15]. In addition, staffing and flexible work schedule were found as a significant predictors of motivation (P<0.05) [38]. Likewise, flexible working hours have been reported as important motivators for nurses [48]. Additionally, the factor of adequacy of leaves can motivate the staff in the organization [57]. However, several demotivating factors affecting nurses' work motivation were also highlighted in the literature such as shift schedule [62] workload [68] staff shortages and inflexible work schedule [29,63]. Furthermore, motivation was very low among health workers who worked more frequent night shifts or encounter a heavy workload [62]. Moreover, inappropriate working conditions can lead to dissatisfaction with the organization as a whole [70].
Availability of resources and infrastructure were predictors of retention and motivation [67]. Moreover, the resource obtainability had the minimum effects on motivating the study population [52]. However, in a study conducted to develop and test instrument for examining the motivation of health care workers to certain job-related aspects and the extent to which these motivate them to achieve better work in India, the results found that job attribution (availability of adequate resources) and good working environment were reported to be the most important motivating factors [57]. In a further study the results demonstrated that demotivating factors in the organizational level include absence of basic services (i.e. electricity and water), lack of drugs and equipment, and poor infrastructure including lack of toilets, housing, and poor access to health facility [29].
Job security was also highlighted in the literature as a factor that affects nurses' work motivation. In a study conducted in India revealed that job security was in the third domain as a factor affecting nurses' motivation [56]. In a further descriptive study, the results reported that the factor of job security can motivate the nurses if the physical and safety basics were provided equally [57]. Moreover, public organisations continued to be very attractive with well job security [42]. However, in a further studies, poor security and health and safety issues at workplace were recognised as demotivating factors [29,63].

Conclusion
The bulk of the literature reviewed has identified the factors affecting nurses' work motivation. Hence, there is an emerging literature exploring the impact of organizational and personal factors related to nurses' work motivation among a number of healthcare organizations internationally. Nurses' work motivation was measured by using different tools. Moreover, the studies were conducted to identify the organisational and personal factors without determining whether these factors affect nurses' work motivation intrinsically or extrinsically. What is not so well recognized and has gained less consideration in nursing so far, is that the quality of a highly-motivated employee's performance may still vary dependent on whether the motivation is EM or IM [11]. Additionally, it should be noted that there are different health care systems and therefore, nurses' work motivation level and factors affecting it are varied from organization to another organization.