This research uses the causal relationship research method. The selected research site included 16 secondary hospitals with the number of beds ranging from 121 to 500, located in both upper and lower northern parts of Thailand. The study was conducted from June 2019-September 2020.

The researcher conducted the right protection of the research participants by submitting a request for approval from Human Research Ethics Committee (HREC), Naresuan University (certificate of approval: COA No.178/2019 IRB No. 0157/62 on 8 May 2019). During data collection process, the researcher also explained the participants about research aims and method and also gave the contact details for any question and ensured data confidentiality and anonymity.

Inclusion criteria: Among these 16 hospitals, there were 300 head nurses in total at the time of the study. The questionnaires were posted to 250 head nurses who fulfilled the following criteria: Registered nurses with a Bachelor of nursing or diploma in nursing and midwifery, have been head nurses/ward leaders for at least one year and willing to participate and gave consent in the research.

Exclusion criteria: Nurses who were uncomfortable. in providing information and unwilling to participate in the research.

Sample size calculation: According to Hair JF et al., [9], the minimum criterion of the sample size for a linear structural relationship model is between five and ten participants for each estimated parameter. This study had 24 parameters and thus required at least 120 participants. While the researcher aimed for a sample size of 200.

The researcher wrote a letter seeking for permission to conduct research and submitted to the dean of Faculty of Nursing, Naresuan University, Thailand and informed the Faculty of the research while asking for permission to travel for data collection. They took permission for doing research from the administrators of secondary hospitals in the north. Finally, a questionnaire was mailed in sealed envelopes to 250 head nurses of the studied hospitals and they were asked to fill the questionnaire and send back by post. Among them, 196 returned the completed questionnaires (78.4% response rate). The data collection took around four months from May 2020-August 2020.

Data were collected by employing a set of self-administered questionnaires which had been distributed by post to examine research objectives and also to investigate factors influencing nurses’ workplace happiness, to test the hypothesis by constructing SEM, and to predict the outcomes using test confirmatory factors. In addition, the survey consisted of two sections. In the first section, demographic characteristics of head nurses were collected through five questions. The second section comprised of a 5-point Likert scale 24 questions aimed at gathering about leader characteristics, work satisfaction, awareness of professional values, organisational climate, social support and workplace happiness and using the mean scores of the sample groups to consider the levels as follows: 1-1.50=Strongly disagree (lowest), 1.51-2.50=Disagree (low), 2.51-3.50=Not sure (moderate), 3.51-4.50=Agree (high) and 4.51-5.00=Strongly agree (highest).

The questionnaire was examined by five experts for content validity and reliability. Content validity index was equal to 0.87. For reliability, Cronbach’s alpha coefficient was obtained as follows: 0.88 for leadership characteristics, 0.83 for work satisfaction, 0.84 for awareness of professional values, 0.89 for social support and 0.94 for organisational climate as well as 0.86 for workplace happiness.

The following are the analysis procedure steps [10]:

The analysis of the SEM starts from retrieving data from Statistical Package for the Social Science (SPSS) for Windows version 17.0 analysing the SEM using linear structural relationships from Mplus program version 8.4. The necessary steps included preparing raw data, constructing a model or picturing a model based on research, deciding model presentation, analysing the model, and adjusting the model based on the statistics of observable variables which had effects on latent variables.

Among the 196 participants, 195 were women; with 148 aged 51 years or above (75.5%); 124 earned a Bachelor of Nursing (63.3%); 118 were married (60.2%); and 59 had working experience as ward leaders from one to five years (30.1%) [Table/Fig-1].

[Table/Fig-2] shows that all factors were rated high in overall scores, ranging from awareness of professional values, leader characteristics, social support, work satisfaction, organisational climate, and workplace happiness.

It is noteworthy that factor loadings of observed variables were all positive from 0.26 to 0.95, with a significance value of 0.001. The observed variable with the highest factor loading was positive affect in the latent variable of workplace happiness while the one with the lowest factor loading was negative affect. An analysis of alpha coefficients of all the observed variables (R2) suggested that covariance of these variables ranged between 0.07 and 0.90.

From the analysis, the GOF with the causal relationship model and the empirical data, by testing with Chi-Square, was found with 238.098 with Degree of Freedom (df) of 205, equal to a p-value of 0.56. This was also equal to a CFI value of 0.99 as well as an TLI value of 0.98. Further, it was equal to a SRMR value of 0.04, and a RMSEA value of 0.02 with a significance level of 0.001.

Given the path analysis of latent variables of factors affecting workplace happiness, awareness of professional values was found with indirect influence at 0.47, with a significance value of 0.001, via other latent variables of leader characteristics, social support, organisational climate, and work satisfaction. Further, the latent variable of work satisfaction was identified with direct impact on workplace happiness at 0.78, with a significance value of 0.001. Awareness of professional values was also indicated with indirect influence at 0.22 with a significance value of 0.001 through work satisfaction. With respect to organisational climate, it was indicated as indirect influence at 0.69 with a significance value of 0.001 through work satisfaction as displayed in [Table/Fig-3].

The factors shown in [Table/Fig-4] were identified to influence workplace happiness among the head nurses: social support, work satisfaction, organisational climate, leader characteristics and awareness of the professional values.

[Table/Fig-4]:

Causal relationship model of factors affecting workplace happiness among head nurses’ of secondary hospital at northern region Thailand.

The current results indicated five factors affecting workplace happiness among head nurses at northern Thailand’s secondary hospitals: work satisfaction, awareness of professional values, leadership characteristics, organisational climate, and social support. These findings are confirmed by Diener E who suggested that happiness components are likely to associate with life satisfaction as well as satisfaction gained from achieving main life goals [6]. These goals may range from work satisfaction, life experience, or actions associated with high positive as well as low negative affect.

In this research, work satisfaction was the most influential factor for workplace happiness in the sampled head nurses with a statistical significance. Among the observed variables of factors, work satisfaction was the one with the highest factor loading (b=0.78). This was also consistent with what indicated that nurses seem to perceive and interpret workplace happiness in accordance with their views and experiences [12]. That is, happiness could be defined as fulfillment, pride, independence which was similar to the findings by Manion J [7]. They stated that love and admiration for work, excitement as well as willingness to perform every aspect of tasks are key reasons for keeping people happy. Also, work satisfaction appears to be commonly reported in other studies [3,5] conducted in different work settings.

As proposed by Warr P, there are three components of workplace happiness: delight in work, satisfaction with work, and enthusiasm for work [13]. Organ DW et al., advocate that work satisfaction, among several other factors, is a transition factor with the highest influence on behaviours of organisational members [14].

Another interesting finding is that awareness of professional values emerged as a factor indirectly influencing workplace happiness via work satisfaction. This was confirmed by Promchoo N, who reported that professional values were positively related to workplace happiness among registered nurses with a high level as well as a statistical significance [15]. Likewise, most registered nurses are likely to be aware of the importance of their profession values which mainly involve sacrifice [16]. Additionally, Edgar L stated that when registered nurses are aware of their professional values, they will be strongly committed to their tasks, attempt to make their best, and attain workplace happiness [17]. Hence, nurses are full of self-esteem and proud to perform their tasks in helping patients recover [18]. Nurses who are satisfied in their jobs, have a sense of giving in terms of Buddhist perspectives, gain respect in the profession as well as have good health (internal factors) are likely to retain their jobs. External factors such as family support, co-worker support in the workplace and high salary were found to be significant for retention [19]. This means that most nurses recognise professional values, originated internally, which can lead to happiness and pride [20].

Such other factors as organisational climate, social support, and leader characteristics also contribute to workplace happiness. That is, factors affecting workplace happiness include a healthy working environment and good relationship with colleagues as well as leaders who provide support and working directions [8]. This result was consistent with those of previous research. For example, Lertwiboonmongkoi J and Angsuroch Y A concluded that challenging tasks that can help develop rational thinking emotions as well as intelligence are essential factors for success and workplace happiness [21]. Promsri C also proposed that workplace happiness tends to occur with good colleagues as well as supervisors [22].

Similarly, iOpener, a UK consulting firm in human resource management says that key factors of working happily contain five components or 5Cs: contribution, conviction, culture, commitment, and confidence [23]. These factors reflect how employees are happy with work while maximising their potential and competency. This is also confirmed by Pathomchaiumporn R and Jadesadalug V who studied the perception of support from organisations that impact employee effectiveness by a balanced score card technique [24]. This technique suggested that the perceived support from organisations consists of support in resource allocation, skill and capacity development as well as information technology were all ranked as high influence on employee effectiveness. From hypothesis testing of this prior work, perceived organisational support was of a positive impact on employee performance. Hence, this means that perceived organisational support can predict workplace happiness as well.

According to the research, it was found that the factor having the most overall influence and direct influence was job satisfaction. Therefore, when the organisation takes this factor into consideration, the head nurses will be ready to work for the organisation and be more loyal to the organisation, resulting in their highest productivity. A better job satisfaction will enhance their happiness at work, and consequently improve their quality of life.

While this research solely used a questionnaire which provides unbiased data, the questionnaire cannot best represent all participants’ opinions or experiences. Additional qualitative tools such as interviews with some participants, open-ended questions, and free-text comments at the end of the questionnaire would complement the quantitative analysis as well as explain some of the results.

The study of the causal relationship model of factors impacting workplace happiness among head nurses at northern Thailand’s secondary hospital demonstrated the following four influential factors: work satisfaction, organisational climate, social support, and leader characteristics. As for the analysis of direct and overall influences on workplace happiness, work satisfaction was the most crucial factor with influence coefficient of 0.78.