Interprofessional Education for Whom? — Challenges and Lessons Learned from Its Implementation in Developed Countries and Their Application to Developing Countries: A Systematic Review

Background Evidence is available on the potential efficacy of interprofessional education (IPE) to foster interprofessional cooperation, improve professional satisfaction, and improve patient care. While the intention of the World Health Organization (WHO) is to implement IPE in all countries, evidence comes from developed countries about its efficiency, challenges, and barriers to planning and implementing IPE. We therefore conducted this review to examine challenges of implementing IPE to suggest possible pathways to overcome the anticipated challenges in developing countries. Methods We searched for literatures on IPE in PubMed/MEDLINE, CINAHL, PsycINFO, and ERIC databases. We examined challenges or barriers and initiatives to overcome them so as to suggest methods to solve the anticipated challenges in developing countries. We could not conduct a meta-analysis because of the qualitative nature of the research question and the data; instead we conducted a meta-narrative of evidence. Results A total of 40 out of 2,146 articles were eligible for analyses in the current review. Only two articles were available from developing countries. Despite the known benefits of IPE, a total of ten challenges or barriers were common based on the retrieved evidence. They included curriculum, leadership, resources, stereotypes and attitudes, variety of students, IPE concept, teaching, enthusiasm, professional jargons, and accreditation. Out of ten, three had already been reported in developing countries: IPE curriculum, resource limitations, and stereotypes. Conclusion This study found ten important challenges on implementing IPE. They are curriculum, leadership, resources, stereotypes, students' diversity, IPE concept, teaching, enthusiasm, professional jargons, and accreditation. Although only three of them are already experienced in developing countries, the remaining seven are potentially important for developing countries, too. By knowing these challenges and barriers in advance, those who implement IPE programs in developing countries will be much more prepared, and can enhance the program's potential success.


Background
Interprofessional education (IPE) is an effective tool to develop collaborations and efficiency among health workers of different professions. Interprofessional education (IPE) occurs when students from two or more professions learn about, from and with each other to enable effective collaboration and improve health outcomes [1]. Evidence reported in Cochrane reviews on the effectiveness of IPE has shown improvement of professional practice and health care outcomes [2,3]. Moreover, IPE has the potential to improve future health workers' clinical and medical knowledge and clinical skills [2][3][4][5][6]. For medical professionals, IPE can help to reduce clinical errors in patient management [4,7]. In this way, IPE can help to improve patient [3] and health worker [8] satisfaction. When individuals of different professions learn together, the experience can break down the professional wall between them, change their attitudes, and reduce stereotypes between professions within the medical field [9,10]. Among students, IPE has been a useful strategy to help change their attitudes, develop their interests in patient care, and improve their medical and clinical knowledge [11][12][13]. Management of patients from different point of views (different professions) is important for the quality of care and wellbeing of the patients.
The World Health Organization (WHO) has endorsed IPE in light of its effectiveness [1]. In its guidelines for transformative medical education, WHO is calling on nations to foster IPE and integrate it in their existing curriculum to yield its desired effects. Integrating IPE in the traditional curriculum is a corner stone for its sustainability and cost effectiveness [14], which can help IPE adoption even in resource-constrained countries. However, due to limited evidence from developing countries, these guidelines were based on evidence derived from developed countries.
A paradigm shift in the epidemiological transition in lower and middle-income countries necessitates a number of health workers from various disciplines to work together to address the pertinent global health challenges. In such countries, the burdens of road injury and non-communicable diseases, such as diabetes, stroke, and cancer, are on the increase [15,16]. Management of such patients requires a team of health workers to work together in collaborative ways [17]. For example, a stroke patient would need a paramedic, a physician, a nurse, a psychologist, and a physiologist for his/her better quality of care and life. An increase in such non-communicable diseases does not mean that the threats of communicable diseases are over [18]. The two will continue to affects millions in developing countries, especially in sub-Saharan Africa, where a chronic problem of human resources for health (HRH) remains a challenge.
IPE has the potential to reduce the HRH crisis [19] in developing countries if properly conducted. It may simplify task shifting when health professionals acquire the necessary competencies [20]. When medical doctors and nurses are trained together, they can acquire some of the skills of the other. Such skills and knowledge transfer can enable one to perform some of the tasks of another. In addition, IPE's role in interprofessional collaboration (IPC) can complement this process. In this case, the burden of patient care may be shared among available health workers as a team in the context of a health worker shortage. IPE may also help to ease the problem of poor HRH retention especially in hard to reach areas caused by the lack of incentives, motivation, and interest of health workers [21][22][23]. To this end, IPE and later IPC may help retain health workers because working in a team can help reduce the burden on individuals and increase their motivation towards their clinical work. The positive results of such collaborations may further foster the spirit of teamwork.
For many years, IPE has been conducted mostly in developed countries [2,6], which provide most of the current evidence. Lessons learned through IPE practice have helped to shape and improve such programs. In contrast, limited evidence is available from developing countries [1]. Lack of evidence on IPE will necessitate rolling out IPE in developing countries based on the assumptions and tools derived from developed countries. This process may be more successful if it also considers the barriers and challenges encountered when implementing similar programs in developed countries.
In developed countries, IPE has had a number of challenges and barriers at its various stages including planning, initiation, and implementation. Although evidence is available for these challenges in developed countries they may be insufficient to extensively examine barriers and challenges in developing countries. However, lessons learned from other IPE programs are vital for implementing IPE globally and encouraging IPE programs in the developing world. This review aimed to 1) examine challenges and barriers to IPE, 2) collect lessons learned while implementing IPE, and 3) make suggestions as to what to expect when planning, initiating and implementing IPE in developing countries.

Methods
We conducted this systematic review to examine challenges encountered while planning, initiating, and implementing IPE in various settings. Furthermore, we aimed to use evidence from wellconducted IPE programs to suggest efficient approaches to implementing IPE in developing countries, which are also suffering from a burden of HRH crisis.
In this review, IPE was the intervention of interest. The population of interest included students, staff, and faculty of medical, biomedical, and nursing schools and institution leaders or managers. We examined challenges or barriers encountered during IPE implementation and possible strategies used to overcome such challenges. The lessons learned from such IPE studies were used to make suggestions for IPE planning, initiation, and implementation in developing countries.
The protocol registration number is CRD 42013006028.
Based on the objectives of this review, we selected only studies that evaluated an IPE program or intervention. The inclusion criteria were studies concerning planning, initiation, or implementation of IPE. We included primary research conducted as cross-sectional quantitative and/or qualitative, prospective cohorts design, and retrospective evaluations of IPE programs. We excluded studies that did not have clear information on IPE planning or implementation. Other excluded articles included opinion articles, commentaries, editorials, reviews, and others that were not based on primary data. Studies on interprofessional learning outside of the health professions were also excluded.
Before the protocol development, we searched for similar studies, protocols, and ongoing reviews on a similar topic. Two reviewers (BFS, HW) conducted the search in the Cochrane Database of Systematic Reviews (CDSR), Database for Abstracts of Reviews of Effects (DARE), and Education Resources Information Center (ERIC).
Two independent reviewers (BFS, HW) conducted the search of evidence in selected medical databases. The included databases were PubMed/MEDLINE, CINAHL, PsycINFO, and ERIC. We limited the search to the articles written in English, with abstracts, and published within the past 25 years (November 1988-November 2013). We constructed the Boolean terms to capture studies on IPE that fulfilled our selection criteria for PubMed/ MEDLINE. We used similar text words and MeSH terms as in PubMed/Medline for other databases.
We retrieved a total of 1,048 articles from PubMed/MED-LINE, 879 from CINAHL, 11 from PsycINFO, and 209 from ERIC. Although we conducted a hand search of the Journal of Interprofessional Care, articles retrieved were similar to those found in PubMed. Therefore, a total of 2,147 articles were available for preliminary screening. We conducted the preliminary screening and excluded a total of 2,045 articles. Such articles did not meet our selection criteria based on content (n = 1080), or were duplicates between PubMed/Medline and other databases (n = 967). A total of 102 were thus available for in-depth screening. At this stage we further excluded a total of 62 articles due to lack of challenges of IPE (15), different context such as IPC (15), opinions or editorials (18), and IPE reviews (12). The remaining 40 articles were analyzed for this study. (Figure 1) Table 1 shows the summary characteristics of the 40 selected articles on IPE programs or interventions. Because of the wide differences in study design, populations, settings, and presented results, it was impossible to conduct a meta-analysis. Furthermore, the outcomes of interest, barriers and challenges, are mostly measured qualitatively. Therefore, we opted to conduct a metanarrative of the data collected. As we had only two articles for IPE programs in developing countries, we first reviewed the 38 articles from developed countries. Then after identifying their common challenges and barriers, we compared them to the two articles from developing countries to develop suggestions for IPE in developing countries.
We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) [24], to conduct this review and report its findings (Checklist S1).

General description of the included studies
A total of 40 studies were eligible for analysis out of 2,147 studies retrieved. Only two studies reported findings from developing countries, which were Egypt [25] and Namibia [26]. Two studies reported findings from more than one country [27,28]. A total of 13 studies were conducted in the US [14,[29][30][31][32][33][34][35][36][37][38][39][40], indicating a high number of IPE programs conducted there. Eight studies [41][42][43][44][45][46][47][48] were conducted in the UK; nine studies [13,[49][50][51][52][53][54][55][56] were conducted in Canada; two in New Zealand [28,57] and Norway [58,59]. Among the selected studies, Australia had one study [28] and so did Singapore [60], Finland [61], Hungary [62], Egypt [25], and Namibia [26]. IPE was conducted in medical universities including teaching hospitals in 30 studies and in other health and academic institutions in eight studies. Because of the nature of our research question, most of the selected studies focused on IPE program evaluation, some in longitudinal designs, and the majority in qualitative design. All the selected studies explained or mentioned the challenges encountered while initiating or conducting IPE. However, a total of 16 studies offered no solutions to such challenges or means used to address them.
Challenges to establish and/or implement IPE varied among institutions and programs. Table 1 shows that common challenges and barriers revolved around common themes. They included IPE curriculum, leadership, resources, stereotypes and attitudes, variety of students, IPE concept, teaching, enthusiasm, professional jargons, and accreditation.        Challenges and barriers in implementing IPE in developed countries 1) Curriculum. A total of 30 studies reflected IPE curriculum as an important challenge to implementing the program. Because of differences in the curricula, curriculum challenges in this research were divided into curriculum content, integration, time and schedule, and course rigidity. IPE course contents, structure, and style of lessons were mentioned as challenges in 10 studies [13,34,38,39,45,51,52,56,57,61]. As for a solution to this, problem based learning (PBL), when it was tried, improved the IPE course because it was based on cases pertinent to the area of the institution involved [45]. It helped to increase interest and attracted more students. Others solved their challenges through a stepwise course structure that started with improving knowledge competence of the lowest level, followed by more complex practices in subsequent levels until IPC was reached in the highest level [51]. Students' evaluation of course content and faculty evaluation of and feedback to students also helped to improve course structure [57]. Innovative approaches including web-based IPE courses also could provide a solution in some settings [34] The lack of integration of the IPE curriculum into the traditional academic frameworks of the professions involved was an important barrier in one study [51]. As a solution, the program involved the institution's faculty members from the relevant fields to develop, evaluate, and sustain the initiative.
Time and scheduling opportunities to implement IPE were the most common curriculum challenges found in 15 studies [13,27,29,33,35,37,42,43,46,49,54,55,58,60,61]. To solve this barrier, some implementers made the IPE subjects and other learning activities a part of the existing core curriculum of the involved professions [60]. Those learning activities were incentivized though grading points [60,61]. Involving professionals [29,36,47,49] and students [42] in the early stages of IPE curriculum preparation alongside their professional curriculum will help the students plan a flexible curriculum [55,58]. It will also help to commit the leadership [33] into addressing some of the time and scheduling barriers.
Two studies pointed to the rigidity of the IPE course structure as a barrier to its sustainability [27,61]. A flexible curriculum aligned with the existing individual school's curriculum may attract and keep students in the program. It may also give time to professionals to participate in other activities while engaging in IPE. Students could participate in the IPE program without altering their professional schedules.
2) Leadership. Poor planning [41], lack of coordination and organization [13,40,45,55], and lack of interest or support by administrators [27,32,47,54,56,60,62] were some of the leadership challenges encountered while initiating and implementing IPE. To address leadership challenges, IPE teams should identify committed champions to spearhead their program [41,45]. Institutional agreements, if formalized, can sustain IPE even when such IPE champions are no longer involved. Committees formed by the IPE actors should get involved from the planning stage [32,55], including seeking support, especially financial support, from outside their institutions.
3) Resources. Lack of funding or uncertainty thereof can affect initiation and implementation of IPE [14,27,28,[34][35][36][37][38][39][40][41]47,50,55,56,59]. Funding is needed for curriculum development, payment of costs and remuneration of staff, staff training to be competent in managing cadres of different disciplines, research costs, and costs for running the program [50]. Additional costs are involved for students' tuition fees and studying materials. Unless the university incurs such costs, running the IPE program cannot be sustainable. IPE programs could thrive using various strategies. Some institutions integrated IPE into their mainstream curriculum to reduce the costs of running parallel programs [14,37]. This also helped to increase IPE sustainability because it was aligned with the same learning environment, teaching objectives, and methods that already existed in their institutions [36]. In addition, this helped to reduce the need to recruit new faculty, which provided additional savings [41,55]. Encouraging results in implementation of IPE programs were mentioned as a driving force for staff regardless of the burden of work [41]. IPE is usually conducted in existing classrooms. These classrooms can be small for IPE classes, which usually include more students than the classrooms were designed to hold. Also, IPE can include students from multiple institutions, which may not be in close proximity to one another. Lack of physical space [34] and longer distances to such classrooms or appropriate facilities for clinical practice [34,35,38] were cited as important challenges to conducting IPE programs. To solve these challenges, and where technology allows, a web-designed IPE could be used to deliver such classes [34]. The modules could be integrated into the parallel curriculum. Also, smaller numbers of students in IPE classes could help to improve interactions [52] and reduce the need for larger classrooms.

4) Stereotypes and attitudes.
Attitudes [27,36,49,53,55] and stereotypes [13,53] held by faculty members are barriers to IPE. Preferences of trainers towards their own professions can undermine the learning process for students who belong to other professions. The medical profession is usually perceived as dominant to other professions [49]. As a consequence, medical doctors tend to over-value their cadres [30]. In most cases, other professions wait for medical doctors to make decisions or lead. This is not healthy for interprofessional teamwork. It creates classes among professionals and impedes collaboration and teamwork to implement IPE. Also, the more the professionals are specialized, the more difficult it is for them to collaborate [13]. Therefore, they may leave IPE for low, basic, or elementary education. Such professional stereotypical attitudes can be transferred to their students [35] and complicate IPE through creating emotions [29], tensions [53], and conflicts [29,41] among faculties and students.
How might such faculty attitudes towards IPE be overcome? In some programs, shared values for IPE and its expected results provided a strong drive to overcome attitudinal issues [41,58]. Faculty development of strategies before implementing IPE can minimize the effects of professional stereotypes [36,49]. It can also increase the sense that IPE is important for teamwork and collaboration among different cadres. Others proposed solutions include the identification of stereotypes and attitudes by staff themselves [29] or through evaluation by the students.
Similar to their teachers, stereotyping is a common problem among students of different cadres [13]. The health professions are based on different disciplines, values, and philosophies. Students pick up such attitudes from their teachers. They can therefore display such attitudes towards other cadres and cause problems in running IPE programs.
Institutional, administrative, or professional bodies' attitudes: Institutional culture [14] and lack of interest towards IPE can make it difficult to implement such programs. Inherent professional tribalism [39,47] and preference towards one's own traditional practice by one cadre over another [55] can cause the left out cadre to feel unwelcome or devalued in the program.
Professional organizations that are constituted entirely of members of one cadre also have been barriers to IPE [49]. The progress of IPE and the positive results thereof may help to reduce such institutional attitudes and increase interest in IPE programs [14]. Involving professional bodies from inception and explaining the role of IPE in their own professions can break the gridlock among such bodies and increase their support towards implementation of IPE. If the champions of the program are school administrators such as deans and faculty leaders, these institutional barriers can be more easily avoided [55]. 5) Variety of students. Students of different professions have different characteristics [49]. They may have different learning needs and basic knowledge levels. For example, nurses and doctors may have different approaches to patient care. Combining such students in a common course without acknowledging their differences [33] could be a barrier to implementing the course [14,46,47,57]. Diversity of students, if unaddressed before the course, may lead to confusion in IPE and in their regular professional courses [29,33]. Successful IPE models acknowledged differences among professions in advance. Students then could learn about each profession and were taught to expect differences of opinion. Conflicts that arose were dealt with immediately and used as lessons to prevent future conflicts. Students' learning needs and capacities were assessed before the course, and common characteristics among different professions were used to plan how to conduct a successful IPE that could benefit all students. Methods such as problem-based learning and cases that were pertinent to all professions involved were employed.
6) IPE concept. The concept and methodology of IPE programs differ from one institution to another [41]. Some consider a top-down approach the ideal model, where IPE is planned and implemented solely by the administrators. Others consider a student-centered model as ideal, where students plan their own IPE programs. Although IPE is effective in improving IPC and professional relationships, the effectiveness of one system over the other remains unknown. With the top-down approach, students are left on the receiving end. They are not part of the design, scheduling, or implementation of IPE. Ownership and enthusiasm may thus be reduced. The IPE concept also is not standardized in most programs. In most cases, by simply studying together the course was considered IPE, even without a clear curriculum. In such situations, the sustainability and longevity of the program remains doubtful. Professions still question the effectiveness of IPE [40]. Because of the lack of clarity and strong curriculum, students remain skeptical of IPE [59]. They might not have clear expectations [29,36] because the IPE course did not have clear aims and goals from the beginning [38,45]. To help solve this challenge, a clear curriculum should be prepared, involving students and other stakeholders throughout the process. The course should be aligned with the school calendar, and goals and expectations should be explained to all participants before starting the course. Stakeholders should own the course and regular feedback and evaluation should be performed. The course should be flexibly modified based on evaluation results. 7) Teaching. Faculty encountered several challenges while teaching IPE. IPE classes were sometimes unusually large compared to regular classes, making it harder for faculty members to interact with students [59]. Because of the differences among cadres, they had to adopt new teaching styles [44,45]. For example, some faculty members might not have been experienced in PBL but had to use it. Moreover, each faculty member might give a different message or professional opinion [53]. This can complicate teaching and consensus might take longer to reach. Differences in professions also can mean differences in learning Integrate IPE into the mainstream curriculum to save operational costs by using available resources and infrastructures [14,37]; Build on positive results to encourage funding, institutional support, and other resources [41]; Conduct IPE on existing infrastructure using the same faculties; Use web-designed IPE to help solve distance and infrastructure barriers whenever possible [34]; Conduct small IPE classes to help minimize the need for larger classrooms and to improve interactions [52] 4 Attitudes and stereotypes [13,14,27,36,39,47,49,53,55,58] [25] Implement faculty development programs before the starting IPE [36,49]; Help faculty to identify stereotypes by themselves [29]; Involve professional bodies from the inception of IPE and explain the role it can have to break gridlocks among them; Involve deans and faculty leaders to break institutional barriers [56] 5 Students' characteristics [14,29,33,46,47,49,57] None Acknowledge the diversity and learning needs of each group before starting IPE; Use PBL to help stimulate learning by different professions 6 IPE concept [29,36,38,40,41,45,59] None Set a clear curriculum and involve all parties before the beginning of and throughout IPE process; Align IPE courses within the school calendar and explain goals before taking initial steps; Provide regular feedback and evaluation to help clear misconceptions 7 Teaching barriers [33,[41][42][43][44][45]50,53,56,57,59] None Encourage faculty to set adequate time for preparations to improve their competency [57]; Provide training to staff on IPE training methods [42,57,67]; Provide the staff with adequate information on students involved including their background and special learning needs [50,57] 8 Enthusiasm [13,27,31,38,51,54,57,62] None Incentivize students who attend IPE courses through grade points or credits to boost participation [51]; Expand practical base using PBL; Involve institutional leaders such as deans to boost enthusiasm [33]; Train and re-train staff and faculties to improve their involvement [62] 9 Profession jargons [42,46,47,57] None Familiarize students with professional terms before the beginning of a class/session; Provide students with printed materials to refer in case the terminology deems difficult but important needs and levels of understanding on various topics [43,44]. Lack of existing research or resources to conduct original research can also impair teaching [56]. Insufficient skills, knowledge and competence of faculty members can hinder the teaching of multiple professions [50,57]. Lack of preparation before the program, including faculty training, can contribute to insufficient competence [57]. Contrasting systems [41], differences in and unfamiliarity with teaching methods and styles for other cadres [33,42], and lack of background information regarding the students involved [33], can also challenge IPE implementation. 8) Enthusiasm. Lack of enthusiasm can result from a poorly planned IPE program. When a top-down approach is taken, participants may not be involved with developing the curriculum and planning the schedule. They also may not be informed about the importance of the program. Then, both students [57] and teachers [13,27,51] may end up with frustration and lack of interest. This can result in poor attendance [54], dropouts, and natural death of the program. In some instances, administrators [62] and one school [31] lost interest and lost the driving force behind IPE because they did not believe there would be a positive outcome [38].
In other instances, efforts were made to boost the enthusiasm and interest of parties involved in IPE. Such efforts included offering students rewards such as credits for attending IPE [51], including the IPE course in the mainstream curriculum [51], and expanding the practical base by using PBL. Even when other aspects lose focus, IPE can still yield its intended results if a strong team is in place [31]. Commitment from administrators, especially deans, is vital to IPE operations. Including such leaders in the program can boost enthusiasm [33]. Training and retraining facilitators and staff can also improve their involvements and enthusiasm [62].
9) Professional jargons. The use of specific terminologies, especially scientific and medical terminologies, acronyms, and pharmacological names, were mentioned as a challenge in implementing IPE [42,46,57]. Changing such terms is unlikely, but explaining them when they are used for the first time can help ameliorate such a challenge. Familiarizing students and professionals with the use of such terms in advance and during the coursework, and providing printed documents of special terminology deemed difficult is also important.
10) Accreditation. To standardize IPE, it is important to accredit the course. There are no specific bodies or institutions to accredit such courses yet [36,39]. This makes IPE seem to be just an additional requirement rather than a serious course for participants [62]. Accreditation of IPE can also help to structure the curriculum in a standardized manner [36]. Despite the lack of such bodies and an accreditation process, institutes adopted IPE models that were successful in other regions [36].
Relevance of the 10 challenges in implementing IPE to developing countries Table 2 shows how the above 10 challenges and barriers in developed countries are included in the literature from developing countries. In this review, only two studies were available from developing countries. These studies also described a number of challenges in implementing IPE. For example, an IPE program in Egypt [25] found that IPE curriculum structure and course or modular complexity were important challenges. Moreover, attitudinal barriers made it difficult to implement the IPE program. In Namibia [26], the IPE program faced resource constraints that included budget and workforce. The need to have strong leadership to guide investment, teaching, and service provision was a necessary ingredient to improve IPE program performance. In these two examples, integration of the IPE program in the mainstream professional curriculum was mentioned as a cornerstone towards building a strong and sustainable IPE program. The three challenges described in developing countries were also common in IPE programs conducted in developed countries. Other challenges extracted from examples of developed countries therefore may be considered potentially relevant to developing countries as well.

Discussion
We reviewed 40 published articles on implementation of IPE. Out of 40, 38 articles were identified from developed countries. Then, we identified ten important challenges and barriers while planning, initiating, and implementing IPE. They included IPE curriculum, leadership, resources, stereotypes and attitudes, variety of students, IPE concept, teaching, enthusiasm, professional jargons, and accreditation. Implementation of IPE programs in developed countries was possible despite the challenges described. When we compared these ten challenges and barriers with two studies from developing countries, we found they identified only three out of the 10 challenges identified in studies from developed countries. It does not mean that the remaining seven were not considered to be challenges or barriers. When IPE programs are increasingly implemented in developing countries, they may face all of them, and it is critical to know these potential challenges in advance.
The studies from developed countries provide examples of implementation of IPE courses despite the above challenges and barriers. These lessons from the past will suggest a way forward for IPE implementation in developing countries.

Anticipated challenges in implementing IPE in developing countries
Evidence is scarce on IPE conduct in developing countries. In this review, only two articles were identified from such countries [25,26]. IPE curriculum structure and complexity, resource limitations, and stereotypes were the three challenges identified from these articles. This evidence may not be generalized to the rest of the countries, as the number is limited. However, examples of challenges and barriers encountered from these and from developed countries can help guide planning, initiating, and implementing IPE in other developing countries.
Money and workforce limitations were barriers in developing countries [26]. Sustainability in funding is a common problem in most medical training institutions in developing countries [63]. The majority of public-owned and operated institutions rely on low budgets from governments [63]. They face difficulties in running even their basic professional courses [64]. Adding a new IPE course based on the same level of budget will impede its implementation and sustainability. Similar approaches to those of developed countries could be considered in the context of developing countries. For example, integrating IPE into the existing curriculum can save the added cost of running parallel curricula [25]. Existing faculties can be involved in its design, initiation, and implementation with minimal or no added costs. Students would not need to travel to other campuses for IPE if faculties within the same university implement IPE together. Seeking independent funds and partnerships with global initiatives can expand the sources of available funds [65].
In developing countries, even faculty members for basic and clinical sciences in training institutes are scarce and those available are underpaid [63,66]. This can impede planning, initiating, and implementing IPE programs. In most of the IPE models in developed countries, a separate IPE course was established with a separate set of faculty members. Such a model is not sustainable in areas with inadequate staff to carry out even the existing professional courses [64]. In developing countries, also, highly qualified and specialized medical professionals are not adequate to guide students through clinical practice. The available specialists are responsible for a high burden of patients [64]. They may not have the time or motivation to teach large IPE classes on clinical training. In this review, some IPE programs that faced such problems in developed countries integrated IPE into the existing professional courses. Available staff received training to help them teach students from different professional backgrounds [67]. Smaller classes were made to foster interactions and programs used the existing teaching hospitals at their training institutions [42]. Similar approaches may bear the desired fruits if adopted by developing countries [25].
The limited number of medical training institutions [63] and large number of students are another common problem in developing countries. IPE has been tested in developed countries with a large number of medical training institutions that have classes with small numbers of students. An IPE class with a small number of students can enhance interactions among different professions and faculties [13]. Clinical practice, especially in PBL, is also efficient in small groups [68]. However, similar approaches might not be possible in developing countries. Models should be built by each institution based on their own situation [69]. Dividing classes into smaller groups [70] can be one approach but might be possible only if the institution has enough physical space and faculty members to manage several groups [13].
Stereotypes, negative attitudes, and the role of professional bodies should not be overlooked in developing countries [25]. Medical doctors in developing countries also tend to be powerful, as are their medical students relative to students in other professional programs. Medical doctors and students tend to be leaders and others act as team players. This attitude is against the spirit of interprofessional collaboration [9,71]. IPE planners should take this into consideration and conduct pre-session training to foster team building and collaboration before the IPE course [72]. Professional bodies such as medical associations may not be strong in developing countries but should also be involved in planning and implementing IPE. Their members are faithful to these organizations. Changing the mindset of senior professionals can be an important approach to mitigating the effects of stereotyping on IPE.
Lack of accreditation of IPE was a barrier in studies conducted in developed countries [73]. In developing countries, introduction of IPE will also face a similar challenge. Lack of accreditation will make such courses less standardized and serious [74]. In most developing countries, even accreditation for regular medical schools remains a problem. Different medical schools may have different styles and approaches to delivering their courses. It may thus be difficult to synchronize IPE among medical schools with different approaches towards similar goals. Efforts to standardize medical schools are necessary and will provide a favorable platform for IPE in such countries, bolstered by accreditation of IPE courses. However, it remains debatable if accreditation of medical schools must be done as a prerequisite for IPE programs.
Poor leadership was a barrier to implementation of IPE in developed countries. For this, evidence is also available from developing countries but it is limited and remains a challenge. In developed countries, strong leaders and their commitment towards IPE were an important reason for success [75]. Similar programs should take advantage of people interested in IPE as champions for the programs in developing countries. School administrators and deans should be involved from the planning stage. Students and other faculties should also take the lead in planning and implementing IPE. In addition, involving the administrators might convince them to provide sufficient budget to help implement and sustain IPE programs.

Tailored approach can help design a sustainable IPE program in developing countries
In developing countries, an IPE program should be designed based on the context of the area in which it is to be implemented. Key stakeholders should be involved throughout the process of planning, initiating and implementing the IPE program. Schedules and timetables should also be taken into consideration. The schedules of professional schools are tight, faculty members are limited, and the number of students tends to be very large. IPE should take advantage of the case studies that successfully generated interest among the participants, and most importantly, aim to solve health problems pertinent to the area [66,76]. Interactions among professionals may be accompanied by some conflict. Such challenges should be solved promptly and amicably. Evaluations by students, faculties, and patients in clinical learning should be conducted frequently and taken seriously for IPE program sustainability.
IPE is important for developing countries despite the likely challenges and barriers. Indeed, they should be taken as opportunities to solve the core health problems in developing countries. For example, IPE can help to foster interprofessional collaboration (IPC) and to address the problem of resource constraints [2]. With strong IPC, a large number of patients in developing countries can be shared within a team and responsibilities can be shifted among cadres of different professional backgrounds. Lack of continuing medical education (CME) and continuing professional development (CPD) in developing countries can partly be solved through IPC resulting from IPE. For example, in well-established settings where health personnel work as a team, senior and experienced health workers can share their knowledge among other staff including those more junior and less experienced. As in developed countries [2][3][4][5][6], IPE in developing countries can improve professionals' medical and clinical knowledge, skills, and professional practices [7]. This will also boost patient satisfaction [7].

Study limitations
The results of this study should be interpreted in light of two limitations. First, we did not find adequate evidence from developing countries where we aimed to make our suggestions. However, the challenges and barriers faced by IPE in developed countries are likely relevant to developing countries where resources are even scarcer. Second, we could not conduct a meta-analysis due to the wide differences in study design, populations, settings, and presented results. However, the metanarrative is more explanatory because challenges and barriers are best measured qualitatively.

Conclusion
This review found a number of challenges and barriers to IPE implementation in studies conducted in developed countries. They are: curriculum, leadership, resources, stereotypes and attitudes, variety of students, IPE concept, teaching, enthusiasm, professional jargons, and accreditation. Out of these 10, three were described in studies conducted in developing countries: resource limitation, leadership challenges and stereotypes. However, challenges observed in this review suggest that the remaining seven are also potentially important for developing countries. By being aware of these challenges and barriers in advance, those who seek to plan and implement IPE programs in developing countries will be much more prepared and their efforts may proceed more smoothly and successfully.