Disclosed Curriculum: Transfer-Climate Mediates Discipline-Diﬀerences in Learner Outcomes

Empirical ﬁndings generally indicate positive eﬀects of early interprofessional education on student outcomes. The current study seeks to add to this evidence base by examining training transfer as an explanatory-mechanism for IPE’s comparative-eﬀectiveness across programs. Speciﬁcally, we examine learner curricular experiences ( transfer climate ) post-IPE delivery in predicting two learner outcomes: 1) team attitudes, and 2) professional identity. A prospective observational design with N= 306 ﬁrst-year students across ﬁve disciplines were assessed before an IPE training and 18-months later. A transfer climate -mediation model was used to test program diﬀerences in team attitudes and professional identity post-IPE training. Results supported full-mediation, such that program diﬀerences in team attitudes and professional identity were contingent on students’ post-training reports of IP experiences ( transfer climate ). In turn, transfer climate ’s eﬀects on team attitudes and professional identity were partially mediated by two IP variables: 1) normative beliefs (professional valuation), and 2) aﬀective reactions (collaboration comfort). The ﬁndings contribute to the identiﬁcation of ‘curricula design factors’ as potential confounds of program-diﬀerences in learner outcomes following early IPE. We discuss the limited value of program diﬀerences in learner outcomes, particularly for studies of early IPE eﬀectiveness. professional identity (ProID) are brieﬂy reviewed as background to our proposed model of TransClim as a mediator (explanatory mechanism) of program-diﬀerences reported in studies of IPE.

findings failed to support the hypothesized negative relation (tradeoff) between ProID and IP attitudes, instead, a significant positive relation was observed (d=.37). Similarly, Adams et al. 18 also found a positive effect of students' teamwork-understanding on ProID (d=.43). To the authors' knowledge, however, there are currently no longitudinal IPE studies of ProID, which prohibits any claims regarding IPE effects on learners' ProID development.
In summary, most arguments against early IPE are predicated on premature ProID, however, few IPE studies have included both ProID and TeamAtts variables in assessments. Still fewer studies theorize specific mechanisms for TeamAtts and ProID development. 8 Consequently, the frequently reported program-differences on IPE outcomes are necessarily of limited validity and insight. The current study seeks to fill this gap by contributing to the argument for early IPE delivery. Specifically, using social identity theory, we identify transfer climate as a common antecedent of TeamAtts and ProID. Below, we briefly elaborate on the explanatory potential of training transfer as determined by curricular experience.

The Disclosed Curriculum -IP Transfer Climate
Cribb and Bignold described the hidden curriculum as the 'processes, pressures, and constraints which fall outside of, or are embedded within, the formal curriculum and which are often unarticulated or unexplored.' 19 Interestingly, early IPE shares the feature of being embedded in formal curriculum. A recent systematic-review of IPE concluded that 'existing curriculum' remains one of the largest hindrances to IP training. 20 We further relate the unexplored "processes, pressures, and constraints" of formal curricula (albeit, thus far, disclosable by student reports) in IPE to a specific criterion of IPE effectiveness, training transfer.
In IPE literature, training transfer is defined by D'Eon as "the ability to extend what has been learned in one context to new contexts." 21 Importantly, in addition to generalization gradients, transfer can also be ordered on a temporal continuum, ranging from proximal, maintenance, distal, and sustainment. This stands in stark contrast to Kirkpatrick Motivation to transfer has received MA support as the largest learner determinant of training transfer (d=.75). 25 Next, we elaborate TransClim and motivation to transfer's role in our conceptual model.

Conceptual Model and Hypotheses
Ronfeldt and Grossman argue that early curricular experiences impact later role transitions and identity integration over training, which has empirical support. 27,28 From the above-reviewed research, Figure 1 illustrates our proposed conceptual model with factors hypothesized to mediate program-differences on TeamAtts and ProID. Specifically, as shown, Program (formal curricula) will systematically expose students to TransClims, post-IPE delivery. Consistent with social identity theory, TransClim is expected to similarly impact motivation to transfer (TeamAtts) and ProID. Thus, we hypothesize that the effect of Program on TeamAtts and ProID will operate indirectly only, as afforded by TransClim following the IPE training.
In addition to the practical role that TransClim may have on TeamAtts and ProID 29 , we explore two theoretical mechanisms by which TransClim is argued to impact TeamAtts and ProID. First, drawing on Fishbein and Ajzen's theory of attitude-formation 30 and Tajfel and Turner's social identity theory 31 , we hypothesize that: Hypothesis 3 (H3): TransClim will positively impact IP-Normative beliefs, and Hypothesis 4 (H4): TransClim will positively impact IP-AffectReact.
Second, theorizing by Ibarra on trialing 'possible selves' in early ProID development suggests that, the valuesignaling beliefs of professions should impact learners' ProID development (normative beliefs). 32 Also, longitudinal evidence on ProID development suggests that students' comfort with teamwork behaviors (affective reactions) impact early ProID development. 33 Both normative beliefs and affective reactions are components of attitude formation. 30 Building on social-psychology theory with models of early-identity negotiations normative beliefs and affective reactions are expected to impact both TeamAtts and learners' early ProID. 34 Hypothesis 5 (H5): IP-NormBeliefs will positively predict TeamAtts and ProID, and Hypothesis 6 (H6): IP-AffectiveReactions will positively predict TeamAtts and ProID.

Method
Our realistic evaluation design is consistent with Thistlethwaite et al. account, whereby we aim to 'identify underlying causal mechanisms and how they work under varying conditions rather than assuming simple cause and effect solutions'. 35

Sample
Students matriculating into an academic medical center in the Southeast United States were recruited to participate in the study. Students represented disciplines of medicine (N=115), nursing (N=95), physical therapy (N=50), physician assistance (N=44), and medical technologist (N=11). A total of N=315 students attended the IPE session and completed a follow-up survey. Nine participants identified as careless responders were removed from the dataset, resulting in N=306. Missing value analysis identified 11 participants with single-values missing across four variables. The missing completely at random (MCAR) test was non-significant X 2 (96)=114.33 (p >.05), and multiple imputation was implemented for recovering missing values. Summary sample characteristics are displayed in Table  1 below.

Procedure
Six week after matriculation, students participated in an IPE training. Instructional delivery comprised a 1-hour didactic followed by three, small-group clinical vignettes designed with high-cognitive fidelity. Trained facilitators moderated the clinical vignettes.
Two weeks before the IPE session, an online survey was administered to assess learner demographics and professional program. A purposive follow-up assessment was conducted 18-months later, during learners' fourth semester. The follow-up survey assessed TransClim, ProID, and team attitude variables. Because the IPE sessions, where collections occurred, were embedded in students' curriculum, completion rates were fairly high at 81%.

Measures
All measures were selected from previously validated instruments and were selected based on sufficient psychometric reporting (Supplementary Appendix 2). Responses were recorded on a Likert-type response format, while our locally developed TransClim measure utilized mixed-response formats. All scores were computed by summing item responses for a total score inputted into structural equation model estimates.

Team Attitudes
Five items were adopted from Heinemann et al.'s Attitudes toward Health Care Teams Scale (ATHCTS) to assess students' evaluative judgments of IP teams. 36 IP-AffectReact (IP-AffectReact) Six items were adopted from King et al.'s IP Socialization and Valuing Scale (IPSVS) to assess affective reactions to engaging in IP interactions. 37

IP-NormBeliefs (IP-NormBeliefs)
Four items were adopted from McFadyen et al.'s Interdisciplinary Education Perception Scale to assess professionbased normative beliefs regarding for IP teamwork. 38 Professional Identity (ProID) Four items were adapted from Jetten et al. to assess students' professional identity (ProID). 39 Transfer Climate (TransClim) Transfer experience was assessed with a locally developed 10-item instrument. Item stems explicitly cued students to report transfer experiences occurring after the IPE training.

Data Treatment
Descriptive statistics, internal reliability estimates, and correlations for all variables are provided in Table 2. All measures exhibited good psychometric properties based on internal reliability estimates (Cronbach's α ranged from .75 -.85). Inspection of the correlation matrix indicated a small, but positive significant correlation between TeamAtts and ProID, providing preliminary empirical support for the mutual-compatibility of TeamAtts and ProID in early IPE.

Measurement-Model Confirmation
Confirmatory factor analysis (CFA) was conducted in order to evaluate the relative-fit of our proposed 5-factor solution for structural-hypothesis testing. Results supporting our hypothesized 5-factor structure are reported in

Structural-Model Hypothesis Testing
Path estimates corresponding to all six of our hypotheses are depicted in Figure 2 below. The first two hypotheses tested TransClim as a full-mediator of Program effects on IP-TeamAtts (H1) and ProID (H2). Full-mediation hypotheses were examined separately.
In summary, five of our six hypotheses received support, whereas one hypothesis received only partial-support. Additional exploratory analyses are reported in Supplementary Appendix 4. Specifically we report: 1) Alternative partial-mediation models for comparison, 2) A further follow-up of medical students' last semester after clinical experience, 3) A joint-variance synthesis from MA estimates of IPE criteria to assess potential reciprocality of outcomes, and 4) A more direct-test of the distinctiveness threat hypothesis from early IPE, which is found to be unsupported. In the Discussion section,

Discussion
The current study builds on prior theorizing and empirical investigations in the IPE literature to offer a latentvariable model of pre-licensure TeamAtts and ProID. Our focal variable in the current model is IP Experiences, specifically, those occurring outside formal IPE delivery. We briefly summarize our empirical findings below.
Support for our first two hypotheses (H1, H2) informs the IPE literature as to the source of program-differences observed for select IPE outcomes. Specifically, the value of program as an explanatory variable for IPE outcomes seems delimited to the training transfer-experiences offered. 41 This should limit the scope of potentially arbitrary inferences made from observed program-differences on IPE outcomes. 42  delivery. 43 Further support for full-mediation effects of Experience on, both IP Attitudes (H2b) and ProID (H2a) was found. However, the effect of Affective Reactions on ProID was non-significant (H4b), which may reflect the slower identity negotiation through continued interaction. 44 This concurs with qualitative evidence indicating that professional identity cannot be taught, but only experientially established in practice. In contrast, the effect of IP Affect on IP Attitudes was significant, providing support for H3b. Furthermore, the findings for Normative Beliefs (H3a & H4a), however, should be encouraging and apropos to a 'just-in-time' trend in the IPE domain. 45 Similar, Thistlethwaite and Ewart have argued for diversity-valuing content in early curricula. 46 It bears repeating, however, that our evaluation design was targeted to galvanize (observe at disequilibrium) the curricular-borne program effects on IPE outcomes. For example, Reeves et al. 10 observe the importance of early-IPE's authenticity as-perceived by students. In briefest, equivalence in training onset (matriculation) does not imply comparable maturation in professional identity or attitude formation. 47 Our findings are complemented by arguments for research of facilitator training and student transfer. 48 More directly, Clouder et al. 49 examined the role that IPE student-facilitators has on widening perceptual scopes of professional identity. Extrapolating, recent longitudinal findings support the effects of learner's identification with instructors, in situ, on trainees' motivation to transfer. 50 In the next section, we briefly elaborate on the theoretical and practical implications of our findings.

Theoretical and Practical Implications
As a preface to implications, we summarize a few reasons for the narrow-outcome foci in extant IPE research. First, as Reeves et al. explicitly acknowledge in the latest systematic review of the evidence, IPE criteria are 'differing, but non-hierarchical.' 12 In essence, in this study, we utilized the vertical-hierarchy of training to explain heterarchicaldifferences on IPE learner outcomes. Second, according to the ubiquitous 3P model of IPE (presage-processproduct), context-and learner-presage factors are orthogonal. Related, each presage factors is reciprocally related to IPE outcomes. Third, the recently published MA 13 of team training in healthcare provided the first empirical support for the empirical relations between IPE criteria, support an indirect-effects model of IPE and results, partly via cascading-determinants (e.g., trainee reactions à student learning à practitioner transfer).
Drawing on tenets of socially influenced attitude formation and identity development processes, we proposed that inclusion of team experiences after IPE delivery can help clarify mixed-findings of IPE's effects on student attitudes and related, positive relations between IP Attitudes and ProID. While arguments against pre-licensure delivery of IPE have waned with growing institutionalization of such programs 1 , rationale for early delivery has centered on defensiveness for mitigating patient hazard. With the abiding burden of IPE's distal-effectiveness, instead, local stakeholders are well-served by an affirmative argument for removing doubts regarding negative implications of IP attitudes for ProID development. For example, the positive relation in these data may be understood in the framework of a Common Ingroup Identity Model 51 (CIIM), which is distinguished from social identity theories that argue for decategorization 31  There are many limitations to the current study that warrant caution for interpretation and generalization. First, while our design was longitudinal, all but one of our study variables was collected at the same assessment occasion. Therefore, there are likely a number of equivalent models that may fit the data equally well. It should also be emphasized that we did not assess attitude change and, therefore, cannot determine from the current data whether the positive relations between our experience factor and attitude antecedents are determinants or correlates. In addition, without a control group, causality cannot be inferred.

Conclusion
The accelerated growth in empirical studies of IPE, not only incommensurate to our meaningful understanding of the phenomenon, but is also an incredible indicator of the strength of evidence Proximal learner outcomes of IPE (reactions, attitudes, and knowledge / skill acquisition) have received empirical support, but specific mechanisms have largely been overlooked. Understanding how IPE influences desired student competencies is important both for the selection into, and customization of, IPE delivery. In addition, the evidence base for IPE on more distal outcomes can be strengthened by identifying potential confounds to IPE effectiveness. 42 In addition, our results highlight an important boundary condition to the interpretation of program differences on IPE criteria, specifically, IPE does not occur in a vacuum and, other curricular experiences necessarily interact with any potential effects of IPE delivery. Consequently, substantive or explanatory inferences of program-differences on early IPE criteria warrant caution. In principle, our findings concur with Brooks and Thistlethwaite's conclusion that, formal learning is the optimal setting for interprofessional learning. 52 Finally, this study provides additional support for the positive relation between ProID and attitudes toward IP teamwork. It is important to understand how normative perceptions of contemporary cohorts influence both factors upon matriculation for optimizing sustainment of necessary early IPE delivery. In closing, there may be space for program differences on short-term outcomes, but is there place in IPE's long-term sustainability?

Declaration of Interest
All authors of the current manuscript formally declare no conflicts of interest.

Take Home Messages
Program-differences on IPE outcomes are confounded by student antecedents and discipline-curricula processes. IP experiences following training support IPE transfer. IPE criteria are interrelated and mutually-reinforcing.