1.1 Rationale

Despite a plethora of studies on Problem-Based Learning (PBL) in medical education, gaps remain in the literature. While PBL is acknowledged for nurturing communication and critical thinking skills, few studies have laid bare its impact on first-year medical students: just as few have done so across different learning contexts-from resource-rich to resource-constrained environments. Moreover, it remains to be seen whether first-year medical students transitioning to self-directed learning face any specific challenges or gains in terms of communication and critical thinking skills utilization by using PBL. Addressing this knowledge gap would help optimize PBL’s implementation and ensure effectiveness among different groups of learners. In this scoping review, the authors summarized data that describe and evaluate PBL efficacy in both resource-rich and resource-constrained settings and identified crucial aspects in further investigations to chart the way for future research. This study lays the groundwork for future investigations into how first-year medical students adjust to PBL and whether more instructional support is required to optimize its effects on their learning outcomes such as critical thinking and communication skills.

1.2 Working definition of problem-based learning (PBL)

In this review, we define problem-based learning (PBL) as a student-centred approach delivered through facilitated small-group tutorials in which an authentic problem scenario (the trigger) is presented first and serves as the main organiser of learning. With guidance from a tutor who facilitates process and discussion rather than delivers content, students analyse the trigger, identify what they know and what they need to learn, formulate learning issues as objectives, complete self-directed study, and reconvene to integrate, discuss, and apply new knowledge. What sets PBL apart from other active-learning approaches is that students generate the learning agenda from the problem and use a structured tutorial cycle to drive learning; in case-based learning, cases more often support application or consolidation of content that has already been taught and objectives tend to be more instructor-defined, while inquiry-based learning is organised around learner questions or investigations that may not use a problem trigger as the central curriculum organiser or follow the PBL tutorial cycle [26].

1.3 Objective

This scoping review maps available evidence on the effects of PBL on critical thinking and communication skills in undergraduate medical education, with a focus on first-year medical students. It seeks to identify key themes and gaps in the literature and compare PBL’s effectiveness in resource-rich and resource-limited settings.

1.4 Research questions

1. What is the effect of PBL on critical thinking skills among undergraduate medical students, particularly first-year students?
2. How does PBL influence the development of communication skills among undergraduate medical students, including first-year students?
3. How do PBL outcomes (critical thinking and communication skills) differ between resource-rich and resource-limited settings for undergraduate medical students?

2.1 Protocol and registration

The review followed Arksey and O’Malley’s Framework for conducting scoping reviews which consists of five main stages. The framework consists of stages such as 1) identifying the research question; 2) ascertaining relevant studies; 3) determining study selection; 4) charting the data; and 5) collating, summarizing and reporting the results [27]. We presented our review report using the PRISMA Extension for Scoping Reviews [28] as shown in Fig 1. A protocol was developed but not formally registered.

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Fig 1. PRISMA-ScR flow diagram.

https://doi.org/10.1371/journal.pone.0342599.g001

2.2 Inclusion and exclusion criteria

The inclusion criteria were that: 1) the main research topic should be related to Problem-Based Learning methodology; 2) the participants should be undergraduate medical students; 3) the main outcomes measured included one or more of the following: critical thinking skills, communication skills, or generic skills problem-solving, analytical reasoning, and collaborative skills; 4) studies should have been published in peer-reviewed journals between 2015 and 2024; The review included empirical studies such as experimental, quasi-experimental, and observational studies; descriptive papers; and studies that used qualitative, quantitative, or mixed-methods approaches. The review excluded the following: 1) studies published in languages other than English, 2) conference papers, 3) grey literature, including opinion articles, commentaries, and editorials, 4) systematic reviews, and 5) scoping reviews. Practical issues, such as a lack of resources to translate non-English studies or the research team not possessing enough proficiency in languages other than English, constrained the review to English language publications. Access and identification of such studies may be difficult as these are often not indexed in databases of the commonly searched. While this method potentially introduces a language bias, this was done to ensure the feasibility and manageability of the review.

2.3 Information sources

We utilized multiple electronic databases to identify relevant literature to meet the objectives of the scoping review. Google Scholar, PubMed, ProQuest, ERIC and the reference lists of included studies, were searched for related literature. These databases were selected to ensure complete coverage of studies related to problem-based learning, Critical thinking, Communication and generic skills (Problem-solving and analytical reasoning). There was no restriction on the geographical location of studies or study design for inclusiveness. We applied a snowballing approach, reviewing reference lists of included studies to identify additional relevant sources.

2.4 Search strategy

A structured search strategy was developed and subsequently run on Google Scholar, PubMed, ProQuest, ERIC and the reference lists of included studies following the establishment of the review objectives. The search was conducted using a structured approach that includes MeSH terms combined with Boolean operators like AND, OR, and NOT to enhance precision and relevance in identifying the pertinent literature.

The main search terms used were “Problem-Based Learning” AND “Critical Thinking Skills”, “Problem-Based Learning” AND “Problem-Solving Skills” OR “Communication Skills”, “Problem-Based Learning” AND “Medical Education”, “Problem-Based Learning” AND “Undergraduate Medical Students”, and “Problem-Based Learning” AND “Communication Skills”. There were no restrictions regarding the date of publication, study design, or country of origin to ensure a comprehensive and inclusive review of the available evidence.

The search was conducted from October 9, 2024, to February 7, 2025. All the retrieved citations were imported into EndNote, version 20.0, for title and abstract screening and data characterization to facilitate systematic organization and analysis. There were no restrictions regarding study designs and country of origin. This enabled a comprehensive and inclusive review of the available evidence.

2.5 Selection of a source of evidence

Studies underwent title and abstract screening, followed by full-text review by two independent reviewers (BAA & AMA). Disagreements were resolved through discussion. A PRISMA flow diagram (Fig 1) illustrates the selection process. Where uncertainty regarding study eligibility arose, all authors reviewed the study collaboratively and deliberated on its alignment with the inclusion criteria to arrive at a consensus. If necessary, discussions between all authors took place (BAA, AA, PG, SK, AM and VM) to resolve such uncertainties.

2.6 Charting

Collaboratively, a data extraction table was adapted from the previous study by the research team members to ensure consistency and accuracy. The data extracted from the publications included general details such as the year, author, study objectives, and study location, as well as specifics about sample size, study design, methodology, intervention, duration, and measured outcomes. The extracted data were systematically compiled into one spreadsheet in Microsoft Excel after which coding and analysis were carried out.

2.7 Critical appraisal of individual sources of evidence

For this scoping review, no critical appraisal was done because the study seeks to map out evidence instead of the quality of individual studies.

2.8. Synthesis of results

3.1. Selection of sources of evidence

The systematic literature search resulted in the identification of 21,001 articles from Google Scholar, PubMed, and ProQuest. After removing duplicates and unrelated articles, 212 unique articles remained for title and abstract screening by two independent reviewers (BAA & AMA). This initial screening excluded a vast majority of studies for not meeting the predefined inclusion criteria. The primary reasons for exclusion at this stage were: (1) studies conducted on populations other than undergraduate medical students (e.g., nursing, allied health, or postgraduate students); (2) interventions that were not Problem-Based Learning (e.g., traditional lectures, team-based learning without a PBL foundation); (3) outcomes that did not include critical thinking, communication, or related generic skills; (4) publication types outside the scope of peer-reviewed empirical studies (e.g., editorials, commentaries, conference papers, systematic reviews); and (5) publication dates outside the 2015–2024 timeframe.

Following the identification process, 212 records were screened by titles and abstracts. During this stage, 162 articles were excluded for not aligning with the inclusion criteria. Specifically, studies were excluded for not focusing on problem-based learning (PBL) (n = 58), addressing outcomes outside the review scope (n = 28), involving non-undergraduate populations (n = 24), representing ineligible publication types such as reviews or commentaries (n = 20), or lacking accessible abstracts for preliminary assessment (n = 32).

Of the 50 studies assessed for eligibility, eight met all inclusion criteria and were retained for the final review. As shown in Fig 1, 42 studies were excluded for reasons including lack of focus on problem-based learning (PBL), unavailability of full texts, absence of relevant outcomes, non-undergraduate populations, or ineligible publication types. Data were charted using a predefined data extraction sheet developed a priori. The sheet captured author and year, country, study design, setting, population and sample size, intervention or exposure and outcome measures (As shown in Table 1). This systematic process ensured transparency, rigor, and reproducibility of the review’s findings.

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Table 1. Data extraction sheet.

https://doi.org/10.1371/journal.pone.0342599.t001

3.2. Synthesis of result

3.2.1. Characteristics of the included studies.

All the reviewed studies originated from Asia, with most (25%) each coming from China, Pakistan and India. Most of the studies (50%) were published in 2018. All the studies (100.0%) were cross-sectional. Also, majority (87.5%) of the studies had no comparator. Further details on the characteristics of the included publications are provided in Table 2.

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Table 2. Characteristics of publications included in the review.

https://doi.org/10.1371/journal.pone.0342599.t002

4.1. Methodological insights and sample size

The reviewed studies revealed substantial methodological heterogeneity in assessing PBL’s influence on critical thinking and communication skills. Researchers employed diverse evaluation tools, including self-reported questionnaires, descriptive feedback analyses, and validated psychometric instruments. This diversity, while reflecting innovation in assessment design, also complicates cross-study comparability and limits the generalizability of results. Recent reviews confirm that the absence of standardized tools and inconsistent methodological rigor remain persistent barriers to synthesizing PBL outcomes [39]. Sample sizes among the reviewed studies ranged from 52 to 464 participants, with a median of 149, underscoring wide variability in statistical power and representativeness. Meta-analytic evidence similarly notes that many PBL investigations rely on small or convenience samples, which constrain the robustness of inferences and magnify study-level heterogeneity [40].

Despite these methodological inconsistencies, the reviewed literature continues to highlight PBL’s promise as an instructional approach that enhances learners’ higher-order reasoning, collaboration, and reflective communication [39]. Future research should prioritize larger, longitudinal, and multi-institutional studies using validated and standardized assessment.

4.2. Critical thinking

Almost all the studies reviewed suggest consistent gains in students’ analytical reasoning, problem-solving, self-directed learning, teamwork, interpersonal interaction, and presentation skills. PBL provide students with the opportunity to interact with case-based scenarios, which fosters higher-order cognitive and communication processes like analytical reasoning, problem-solving, collaborative and interpersonal skills, which are fundamental for clinical decision-making [31,32]. The interactive components of PBL, including group discussions and role-playing, have a better reinforcing effect on critical thinking and communication skills by enabling students to express their reasoning, defend their decisions, and take part in peer learning.

4.3. The interconnectedness of critical thinking and communication skills

Reviewed studies from China and Saudi Arabia indicates that PBL interventions have made a significant contribution to the growing body of evidence concerning the ability of PBL in promoting critical thinking and communication skills [31,33]. Besides fostering critical thinking, PBL has been reported to associated with the indicators of improved communication skills like teamwork, interpersonal communication, and presentation skills [35,37].

4.4. Resource-rich vs resource-limited settings

Across the reviewed studies, PBL appeared feasible in resource-limited settings where formal communication-skills training and extensive instructional infrastructure may be limited. In these contexts, the small-group tutorial cycle can support verbal expression, active listening, and peer feedback through repeated discussion and reflection, with the tutor facilitating group process rather than delivering content [36]. Consistent with this, peer learning and structured case discussions may partially substitute for faculty-led instruction when faculty time, teaching space, or learning resources are constrained [35,36].

In contrast, studies conducted in settings like Saudi Arabia [34] and China [32,33] with stronger infrastructure and faculty capacity more often reported the use of additional structured learning activities (for example, role-plays, debates, or expert-led sessions) to extend practice opportunities for communication and reasoning. In the reviewed evidence set, these studies reported improvements in communication and reasoning outcomes, although it is not always clear whether these gains were attributable to PBL alone or to PBL combined with these supplementary activities. Where PBL is implemented with such enhancements, they should be reported explicitly as part of the intervention package to avoid misattributing effects to PBL alone.

Essential resources for PBL implementation include trained facilitators, protected time, small-group space, and access to learning materials that support self-directed study. In resource-limited contexts represented in this review (for example, Pakistan, India, and Nepal), constraints in faculty development and institutional capacity were common, yet PBL remained implementable through a structured tutorial cycle that emphasised peer learning and guided discussion. A minimal viable package in such settings includes contextually relevant problem triggers, basic learning resources, targeted tutor preparation, and peer-mentoring structures that reduce facilitator workload.

Overall, the reviewed evidence suggests that PBL can support critical thinking and communication skill development across resource contexts, but the magnitude of effects may depend on implementation quality and the availability of enabling resources [35,36].

4.5. First-year medical students

However, little is known about the acculturation of first-year students into the PBL approach, and few reports have documented it, especially in resource-limited settings. With first-year students facing significant challenges in the transition from traditional, teacher-center learning environments to the more self-directed and collaborative nature of PBL, challenges might include self-directed learning, time management, and group dynamics; all of which are crucial within PBL settings [13,16,31,35]. In resource-limited settings, however, the aforementioned challenges may be compounded by insufficient faculty support, inadequate technical resources, and limited training in communication skills. Due to the inherent requirements of PBL, first-year medical students may need additional assistance if they are to be successful in making the transition to this instructional approach. Explicit direction by curriculum committees within institutions, faculty development activities, or oversight by national accrediting agencies can help ensure a smoother transition. Such support is necessary to allowing students to achieve the maximum benefits of PBL, particularly in critical thinking and communications skills acquisition. It’s unknown how much they find it difficult to learn on their own, solve problems in groups, and adjust to a less regimented style of instruction than traditional lectures. Guidance can be provided through national accreditation bodies, curriculum review boards, and faculty development programs.

4.6. Influence of cultural and diverse educational backgrounds

A key limitation of this scoping review is that, although “cultural background” and “educational background” were recognized as possible moderating factors, the studies reviewed did not examine them systematically. The absence of this analysis restricts how far the findings can be applied in real-world settings, especially where problem-based learning (PBL) is introduced to groups of students with diverse cultural and educational profiles. Evidence increasingly shows that such factors shape how learners engage with and benefit from PBL. For instance, Kebaetse, Griffiths [41] reported that sociocultural norms such as valuing silence as a sign of respect hindered both self-directed learning and group interaction in an African medical school’s PBL program. Similarly, Nicolaou, Televantou [42] observed that students with biomedical backgrounds began PBL pharmacology sessions with clear performance advantages. However, these advantages did not necessarily translate into greater learning gains compared to their peers from non-biomedical pathways.

Broader scholarship reinforces these observations. Chan, Gondhalekar [43] found that in non-Western settings, students’ perceptions of tutor authority and group dynamics were shaped by cultural values such as power distance and collectivism. Likewise, Leatemia, Susilo [44] showed that tutors’ own cultural and educational orientations influenced their facilitation styles, which in turn affected how much autonomy students exercised. Taken together, these studies demonstrate that cultural and educational backgrounds are not peripheral issues; they fundamentally shape how PBL fosters communication, collaboration, and critical thinking. Addressing these moderators should therefore be a priority for future research.

4.7. Conclusion and future directions

Prioritizing multi-center studies and consistent techniques will help to boost future research. More comparison analyses and trustworthy results will be possible with the use of standardized evaluation instruments and consistent study designs. To ascertain whether first-year medical students need extra assistance with self-directed learning, adjusting to PBL, and cooperative problem-solving, more research should look into their experiences, especially regarding how their critical thinking and communication skills are developed due to the problem-based learning experience. This is especially crucial in environments with limited resources, as students might not have as many chances and opportunities in terms of resources, technology, faculty and infrastructure as compared to their counterparts in the developed world. By addressing these research gaps, PBL implementation techniques will be improved and universal access to high-quality medical education could also be improved. Furthermore, Future studies should focus on multi-Centre studies, standardized methodologies, and technology-enhanced PBL models to optimize its effectiveness in diverse educational contexts. This review found no studies from Africa, highlighting a gap in PBL research within low-resource settings. Future studies should explore how PBL is implemented in diverse cultural and economic contexts.

4.8. Limitations

There are several limitations to this scoping review. The overall number of studies that were included was small (n = 8), and only one of these focused specifically on first-year medical students, which lowers the generalizability and degree of analysis. The studies varied considerably in design, sample size, and assessment tools. Due to heterogeneity in study designs, populations, and outcomes, conducting a meta-analysis was not appropriate. This is consistent with the aims of scoping reviews, which focus on mapping the breadth of evidence rather than producing pooled effect estimates [27,28]. Instead, we used both descriptive and thematic synthesis to summarize study characteristics, identify recurrent patterns, and highlight evidence gaps. Most of the studies employed self-reported data that may yield subjective bias and undermine the validity of the findings. Furthermore, all the included studies were conducted in Asian countries, and none of them were conducted in African, European, or American settings, thereby decreasing the geographical generalizability of the evidence. Lastly, the lack of longitudinal or experimental designs restricts the degree to which long-term impacts or causality may be inferred.

4.9. Conclusion

From the scoping review, PBL may be associated with perceived improvements of critical thinking and communication skills. The findings, however remain tentative, need to be drawn cautiously considering the limited number of qualifying studies and the prevalence of cross-sectional, self-reporting designs. Specifically, there was only one study that focused exclusively on first-year medical students, and therefore, it was not straightforward to ascertain their specific experience and challenges with PBL. Moreover, the absence of studies from African and other underrepresented parts of the world limits the generalizability of the findings across various learning environments. Standardization of methods in future research and broader geographical representation can give elaborate insights about the effects of PBL and therefore could inform its effective application in both resource-rich and resource-limited settings.

4.10. Practical implications for educators implementing PBL

This review highlights several actionable lessons for educators who apply problem-based learning (PBL) in undergraduate medical education. In resource-rich settings, the priority is to make full use of available infrastructure. Digital platforms and simulations can enhance realism, while skilled facilitators can move beyond managing groups to guiding higher-order reasoning and professional reflection. These environments also make it possible to monitor learning progress and provide targeted feedback that supports both cognitive and communication skill development.

In contrast, educators in resource-limited contexts must rely on strong pedagogy rather than technology. The design of clear, relevant clinical cases and effective facilitation become the main tools for promoting learning. Structured peer mentoring can reduce faculty workload, and community settings can serve as authentic learning environments that connect theory with local health realities.

Supporting first-year medical students requires additional care. Because they often struggle with self-direction and teamwork, PBL should begin with structured orientation sessions that introduce its goals and methods. Early cases should be guided and gradually increase in complexity as students gain confidence. Educators should also teach collaboration explicitly, rather than assuming that teamwork will develop naturally.

Finally, cultural and educational diversity demands contextual adaptation. Case scenarios and facilitation styles should reflect local values, communication norms, and health-system conditions. Forming balanced groups and assigning rotating roles can ensure equitable participation. Ultimately, effective PBL implementation depends on educators’ capacity to adapt its principles to their resources, learner needs, and cultural realities while maintaining its core aim, developing reflective, competent, and collaborative practitioners.