1. Introduction
While “identity” refers to people’s perception of who they are, what kind of people they like to be, and how they are connected to others [
1], “social identity” refers to people’s self-perception of what social group they belong to in connection with certain values and emotional attachments to that group [
2]. “Professional identity,” as one form of social identity, refers to people’s professional perception of themselves based on their values and beliefs, which guide the way they think, behave, and interact with social and professional norms [
3,
4]. Adams et al. [
5] defined professional identity as the attitudes, values, knowledge, beliefs, and skills shared with others within the same professional group. It is also one’s perception as a professional sharing a set of beliefs, attitudes, and knowledge, and one’s understanding about one’s role within the work context [
5,
6]. Shared identity can also help professionals to differentiate themselves from other professional groups in the work context [
5,
7]. In addition, those having stronger identification with their professional group have greater job performance, satisfaction, and retention [
8].
Professional identity among healthcare professionals refers to one’s awareness of being a professional in the healthcare field and one’s identification with healthcare groups and contexts that one belongs to by virtue of one’s occupation or career. The formation of professional identity involves an intra-individual process in which individuals are not only motivated but are cognitively prepared to employ their expected professional talents and competencies [
9]. Moreover, it involves a formation of “collective identity” [
10], in which individuals have to share certain attitudes, values, knowledge, beliefs, and skills within the same professional group, hence differentiating themselves from other professional groups in the work context [
5].
Kroger and Marcia [
11] noted that the construction of professional identities is crucial in the transition from adolescence to adulthood. Therefore, college students have to devote much more effort to exploring what they want their future profession to mean to them and who they want to be—while simultaneously pursuing the professional knowledge necessary to achieve those goals [
12]. Via the exploration of professional identification, they may determine that they are ready to make a commitment to their chosen profession [
13]. Research has shown that the professional identity of healthcare students is socially constructed [
6,
14]. The way medical care students understand their professional boundaries and the way they interact with patients or colleagues influence their expectations, actions, and judgment in their profession, as well as their future professional lives [
15]. In healthcare, professional identity can somehow soothe the negative effects of a high-stress workplace. Those healthcare professionals with a stronger professional identity can not only benefit themselves, but also positively impact their patients and coworkers [
16,
17], because they know how to manage their professional roles. They can perceive themselves as a professional under a set of shared attitudes, values, and beliefs within the same professional group [
5,
6]. In addition, while thinking, acting, and interacting with patients within social and professional norms [
3,
4], they will have less difficulty in communicating with co-workers and patients. Hence, somehow, their work stress can be relieved.
The way healthcare professionals perceive themselves influences what kinds of choices and judgments they make and, therefore, impacts their professional attitudes, values, and commitment in healthcare contexts. Healthcare professionals’ and students’ professional identities are socially constructed by their social interactions with others in the healthcare workplace [
16]. Therefore, they know how to interact with patients and patients’ families. Moreover, they may realize the boundaries of the healthcare profession and, hence, learn how to interact with other healthcare professionals to facilitate interprofessional healthcare teamwork [
6]. Thus, healthcare professional identity may be defined as a set of beliefs, attitudes, and understanding about one’s role in the work context and healthcare system [
6,
14].
However, in the healthcare service, there are still differences in the responsibilities tied to different disciplines. Certain professionals in the same discipline, such as in the disciplines of medicine, nursing, social work, medical laboratory technology, or hospital administration, may share the same disciplinary responsibilities, which are quite different from those of other healthcare disciplines, thereby leading to different professional identifications in the healthcare service, albeit under the roof of healthcare. Each single professional discipline shares certain conceptualizations of professional identity. For example, those sharing the profession of doctor share the same conceptualization of professional identity. However, doctors, nurses, social workers, and counselors, though all working in the healthcare service, share different conceptualizations of professional or disciplinary identities and, hence, may have difficulties while addressing crucial healthcare issues in the complicated healthcare system.
Thorne [
18] mentioned that, generally, medical professionals are initially resistant to change; however, while perceiving their professional boundaries, they may negotiate and adapt to the existing medical and healthcare contexts. Moreover, while realizing their professional boundaries, they may cross intra-professional boundaries and move toward interprofessional boundaries to redefine and reinterpret their interprofessional identity. Thus, through exploring their intra-professional and interprofessional identification in the healthcare system, they can later collaborate with their colleagues, both intra-professionally and inter-professionally, in different disciplines. In other words, healthcare professionals need to have not only an intra-professional identity, but also an interprofessional identity in order to facilitate collaboration and deliver integrated care to patients [
19]. With dual professional identities, healthcare professionals are able to smoothly integrate various facets of their professional lives and manage potentially difficult clinical or healthcare situations involving interprofessional collaboration with greater ease.
Although professional identity development is an important concept in healthcare education, the process has not been well investigated from the perspective of collective healthcare professionals. Professional identity scales measuring a specific healthcare or medical care group may be informative in assessing the professional identity in that certain healthcare group; nonetheless, these scales, tailored to a certain group, are not appropriate to measure the collective professional identity among an interprofessional community of healthcare professionals. Therefore, in order to facilitate healthcare workers’ interdisciplinary collaboration and to identify themselves as a cohesive community within the healthcare system, healthcare professionals or students must have a shared professional identity, or a dual identity, through which they can maintain interprofessional roles while keeping their specific professional roles. In other words, through shared identity, healthcare professionals can identify with their specific professional groups, interdisciplinary communities, and the healthcare system as a whole [
20,
21].
4. Discussion
This study was intended to develop a scale to measure the professional identity of healthcare students and professionals and to help them acclimate to the interprofessional healthcare system, hence, interpreting or reinterpreting their existence and meaning in their interprofessional identification process. The study first used the EFA to get a longer and preliminary version of the PIS-HSP scale, which yielded 33 items and four factors, accounting for 68.59% of the variances. In the study, the researchers used the varimax rotation to obtain the greatest possible variance, which generally lies in the first factor [
29]. The four factors were “professional commitment and devotion” (16 items), “emotional identification and belongingness” (7 items), “professional goals and values” (5 items), and “self-fulfillment and retention tendency” (5 items). The average item scores on the four factors reveal that the participants agree with the values of healthcare and believe that their profession contributes to society. However, they sometimes feel exhausted and have a negative perception of self-worth in response to the current healthcare situation. The factor loadings on each single factor of the PIS-HSP were in the range between 0.61 and 0.89. According to Hair et al. [
37], factor loading values above 0.50 are considered adequate, and those above 0.70 are considered good. Hence, it can be suggested that each item is adequate or good for measuring the factor. The Cronbach’s alphas for the four subscales and the overall scale were in the range between 0.84 and 0.96.
Further, the study used the CFA to examine the fitness of the model extracted by the EFA and the underlying latent variable structure of the PIS-HSP scale; the study reduced the preliminary 33 items to 18 items, removing items 66, 84, 61, 63, 43, 48, 79, 37, 50, and 33 in factor 1; items 16, 14, and 21 in factor 2; item 19 in factor 3; and item 73 in factor 4. As a result, a shorter version of the PIS-HSP scale was developed, with only 18 items: professional commitment and devotion (6 items), emotional identification and belongingness (4 items), professional goals and values (4 items), and self-fulfillment and retention tendency (4 items).
The factor loadings for each item ranged between 0.563 and 0.943, suggesting acceptable factor loading values [
37]. Hence, it can be demonstrated that each item in the CFA model is an adequate to good indicator of the factor. As for the evaluation of the goodness of fit, while using the multiple fit indices to examine how well the model fit the data, the indices of the baseline EFA model show acceptable model fits in TFI (0.912), CFI (0.918), and RMSEA (0.068), but not in the χ
2/df ratio (3.374;
p-value = 0.000). In the CFA model, the model fits in TFI (0.997), CFI (0.997), and RMSEA (0.016) increased from “acceptable” to “excellent.” The χ
2/df ratio (1.138;
p-value = 0.146) was acceptable. Hence, it can be said that the PIS-HSP scale has good or even excellent model fit and, hence, has an appropriate and reliable factor structure [
36,
37,
38,
39].
In terms of convergent validity, among the four factors, the AVE values of the “professional commitment and devotion,” “emotional identification and belongingness,” and “professional goals and values” factors were above the cutoff value of 0.5 and below the composite reliabilities. However, the AVE value of the “self-fulfillment and retention tendency” factor was 0.477, with a composite reliability value of 0.782. Though the AVE value 0.477 is not above the cutoff of 0.5, with the composite value above 0.6 the convergent validity is acceptable. According to Fornell and Larcker [
39], if the AVE value is lower than 0.5, but the composite reliability value is above 0.6, the convergent validity is confirmed.
Turning to discriminant validity, based on the Fornell-Larcker criterion [
39], the square root values of the AVE for each factor should be higher than the correlation between the factors. Based on the criterion, the results proved the discriminant validity between the “professional commitment and devotion” and “professional goals and values” factors, between the “professional commitment and devotion” and “self-fulfillment and retention tendency” factors, between the “emotional identification and belongingness” and “professional goals and values” factors, between the “emotional identification and belongingness” and “self-fulfillment and retention tendency” factors, and between the “professional goals and values” and “self-fulfillment and retention tendency” factors. There is a marginal discriminant validity between the “professional commitment and devotion” and “emotional identification and belongingness” factors. One explanation for the derived marginal discriminant validity could be that although the sample size (
N = 509) was acceptable to ensure a meaningful and sound evaluation, the size might not be big enough to eliminate bias [
40]. According to Hair et al. [
37], the sample size should be at least five times the number of items used in the scale (a 5:1 ratio). A more acceptable sample size should be ten times the number of scale items (a 10:1 ratio). In the study, the sample size (
N = 509) met the minimum criterion of sample size 435 (5 times 87 items), though not reaching the more acceptable size (10 times 87 items).
The reliability of the CFA model for the PIS-HSP scale was established by calculating Cronbach’s alpha and composite reliability statistics. According to Cunha et al. [
41] and Fornell and Larcker [
39], the value between 0.8 and up to 1.0 is considered very high. The minimally acceptable level of reliability is 0.70 [
30,
31], because all the Cronbach’s alphas values were higher than 0.70, some even higher than 0.90. Thus, the internal reliabilities of the subscales and the overall scale are considered good [
37,
38,
39,
41]. Based on the above validity and reliability examination, the research results support the four-factor structure, consistent with the baseline EFA model for the PIS-HSP scale, as well as good internal consistency.
In light of these findings, the developed CFA model and the baseline EFA model for the PIS-HSP scale can be used as formal scales to measure professional identity for healthcare students and professionals, with the baseline EFA model being the long form and the CFA model being the short form.