Effectiveness of case-based learning in comparison to alternate learning methods on learning competencies and student satisfaction among healthcare professional students: A systematic review

Abstract

To evaluate the effectiveness of case-based learning (CBL) versus alternate learning methods on learning competencies and student satisfaction among healthcare students. A systematic search of the PubMed, SCOPUS, CINAHL, and Cochrane CENTRAL databases was conducted from database inception to December 31, 2021. The grey literature, Google Scholar, and hand searching were also conducted. The keywords used were “case-based learning,” “case learning,” “traditional learning,” “problem-based learning,” “simulation-based learning,” “learning competenc*,” “competenc*,” “student satisfaction,” “satisfaction,” “medic*,” “dent*,” “nursing” “pharmac*,” “students,” “undergraduate,” “postgraduate,” and “clerkship.” Only studies comparing CBL methods with a control group or with an alternate learning method conducted on healthcare students were considered. The risk of bias was assessed independently by two reviewers. Data analysis was undertaken using RevMan 5.4. Twenty-two studies were included in the final review, of which 20 studies compared CBL with lecture-based learning (LBL) and two compared CBL with simulation-based learning. Pooled data demonstrated that critical thinking scores were significantly higher among those receiving CBL than those receiving LBL (standardized mean difference (SMD): 0.75, 95% confidence interval (95%CI): 0.21–1.29). Similarly, significantly greater scores for teamwork and communication were identified in the CBL group than in the LBL groups (SMD: 0.24; 95%CI: −0.19–0.66). However, no significant difference in knowledge and comprehension scores (SMD: 0.41; 95%CI: 0.20–0.62) and self-directed learning (SMD: 0.30; 95%CI: 0.10–0.49) was identified among those who received CBL compared to those who received LBL. Based on the results of this review, CBL has been identified as a superior teaching method as it significantly improves critical thinking, problem-solving, teamwork, and communication skills and enhances clinical skills development and student satisfaction. However, more rigorous RCTs are needed to underpin the available evidence.

Introduction

Education for healthcare students has transformed from traditional instructional models focused on lecture-based instruction to other pedagogical approaches, including problem-based and case-based learning (CBL). The conventional lecture-based instruction method concentrates on delivering the content and does not allow discussion or active student involvement.[1] In the traditional teaching method, little attention is given to problem-solving, collaborative learning, and lifelong learning strategies.[2] This makes students lose motivation and lack self-study ability, and the integration of curriculum and clinical work is insufficient to train students’ critical thinking. This method is less effective than other teaching strategies in practical application and critical thinking abilities.[3,4]

CBL is a pedagogical approach that aims to forge clear links between theoretical knowledge and clinical practice by engaging students with authentic clinical cases that contextualize knowledge and promote high-order competencies, including critical thinking.[5,6,7] Many disciplines, including business, science, education, humanities, and law, have incorporated a CBL approach to tertiary education.[8] CBL is learner-centered because students work collaboratively in small groups to solve the case. The teacher moves from the role of an expert to an expert guide, providing structure, direction, and advice rather than solutions.[7] Active participation from both students and educators supports knowledge and competency development, especially as the case reinforces the application of knowledge.

Despite the seemingly long history of CBL in healthcare disciplines, the delay in the widespread adoption of CBL in healthcare professional education needs to be highlighted.[9,10] The dominant model of healthcare professional education relies on clinical placement experience. Here the novice professional observes the expert professional and learns how to apply theoretical knowledge and skills in clinical practice. Reliance on peer teaching and practical exposure to a broad range of clinical situations while in the clinical setting are fraught with problems due to operational considerations outweighing teaching time, variable facilitator ability, and caseload at any particular time.[9] Moreover, undergraduate healthcare students cannot learn clinical judgment or reasoning through observation because the processes used by experienced or expert practitioners are not visible.[11,12,13] International reports suggest that inadequate clinical reasoning competence is part of the problem of “failure to rescue.”[14,15,16] There is a need to teach these higher-order skills to undergraduate healthcare students explicitly so that they are adequately prepared for clinical practice.[13,17]

Students are more likely to be engaged in this method, primarily when delivered in small groups and provided with constructive feedback. Second, teachers also had a positive attitude toward CBL, potentially leading to a productive classroom experience. Lastly, the combination of more engaged students and authentic cases suggests adequate knowledge and competency development in small-group learning.[5]

Results from a systematic review published in 2012,[5] which included 104 studies, indicated that the evidence base for CBL within healthcare undergraduate education was limited by the poor methodological quality of the majority (n = 81) of the studies, and the outcomes focused on the assessment of student reaction to CBL (n = 86). The review found that while healthcare students positively respond to CBL, the effect on learning outcomes, including improvements in knowledge and attitude, was limited to a few studies. The demands of modern healthcare and the current crisis created by the COVID-19 pandemic have reinforced the need to ensure that new graduate healthcare professionals are work-ready with higher-order skills. Following the publication of the initial systematic review in 2012,[5] numerous RCTs and non-RCTs have been published investigating the effect of CBL on learning competencies. The purpose of this present review is, therefore, to evaluate the effectiveness of CBL versus alternate learning methods on (1) learning competencies including critical thinking, knowledge and comprehension, self-directed learning, problem-solving, and clinical skill development, (2) teamwork and communication, and (3) student satisfaction among healthcare students.

Materials and Methods

The protocol for this review is registered in the PROSPERO database (CRD42021238214) and follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines.[18] Digital databases of PubMed, SCOPUS, CINAHL, and Cochrane Library were searched for relevant studies published in English. In addition, the first 20 pages of Google Scholar were searched, and hand searching of five major education journals was performed. Studies published from inception until March 17, 2022, were included. Keywords/index terms used were “case-based learning,” “case learning,” “traditional learning,” “problem-based learning,” “simulation-based learning,” “learning competenc*,” “competenc*,” “student satisfaction,” “satisfaction,” “medic*,” “dent*,” “nursing” “pharmac*,” “students,” “undergraduate,” “postgraduate,” and “clerkship” [Supplementary File Tables S1-S4].

Table S1.

Search Strategy [Pubmed] search conducted on 31-12-2021

Search		Query		Records Retrieved
#1		“case based learning”		799
#2		“CBL”		4834
#3		“alternate learning”		31,353
#4		“problem based learning”		10,567
#5		“lecture based learning”		134
#6		didactic lecture		878
#7		competen*		259,793
#8		“student satisfaction”		1070
#9		“Medic*”		10,798,846
#10		“Dent*”		971,022
#11		“Nurs*”		1,047,085
#12		“Pharma*”		5,079,888
#13		#1OR#2		5498
#14		#3OR#4OR#5OR#6		15,582,504
#15		#7OR#8		8,154,512
#16		#9OR#10OR#11OR#12		9,953,156
#17		#13AND#14AND#15AND#16		280

Table S4.

Search Strategy [CINAHL] search conducted on 31-12-2021

ID		Search		Records Retrieved
#1		case based learning [mh] OR cbl		4677
#2		Alternate learning [mh] OR Problem based learning [mh] OR lecture based learning [mh] OR didactic lecture [mh]		32,989
#3		Competen*ORStudent satisfaction [mh]		6,54,890
#4		Medic*OR Dent*OR Nurs*OR Pharma*		12,675,96
#5		#1AND#2AND#3AND#4		172

Table S2.

Search Strategy [Cochrane CENTRAL] search conducted on 31-12-2021

ID		Search		Records Retrieved
#1		(“case based learning”or “CBL”)		120
#2		(“alternate learning”or“problem based learning”or”lecture based learning”or didactic lecture)		3971
#3		(competen*or”student satisfaction”)		3998
#4		(“Medic*”or”Dent*”or“Nurs*”or“Pharma*”)		1,772,897
#5		#1AND#2AND#3AND#4		5

Table S3.

Search Strategy [Scopus] search conducted on 31-12-2021

ID		Search		Records Retrieved
#1		TITLE-ABS-KEY ((“Case Based Learning”) OR (“CBL”))		8762
#2		TITLE-ABS-KEY ((“Alternate learning”) OR (“Problem based learning”) OR (“lecture based learning”) OR (“didactic lecture”)		20,171
#3		TITLE-ABS-KEY ((“Competen*”) OR (“Student satisfaction”))		4,82,520
#4		TITLE-ABS-KEY ((“Medic*”) OR (“Dent*”) OR (“Nurs*”) or (“Pharma*”))		8,523,44
#5		#1AND#2AND#3AND#4		96

Eligibility criteria

Studies were included if they were either randomized control trials or quasi-experimental studies that compared CBL to alternate learning methods in undergraduate and postgraduate medicine, dental, nursing, and pharmacy students. Studies without a control group, pre-post-test surveys where groups act as self-control groups, and those that combined CBL with other methods were excluded.

Study selection

The COVIDENCE software was used to import studies, remove duplicates, screen studies, and record decisions.[19] Title and abstract screening and full-text screening of studies were done independently by two reviewers (BV and VK), and any conflict was resolved by discussion with the research team.

Data extraction and synthesis

Data extraction was undertaken independently by two reviewers (BK and VK) and was checked by all the reviewers. Data extracted included details of study design, stream of healthcare, sample size, details of CBL and alternate learning methods adopted, duration of intervention, instruments used to measure outcomes, and the following outcomes: 1) learning competencies, including critical thinking, knowledge, and comprehension, self-directed learning, problem solving and clinical skill development; (2) teamwork and communication; and (3) student satisfaction among healthcare students.

Meta-analysis was performed using RevMan software version 5.4.[20] For individual studies, where appropriate, the mean and standard deviation (SD) were extracted. The standardized mean difference (SMD) and 95% confidence interval (95%CI) were calculated as the measurement scale differed across trials. In addition, categorical data were extracted from each treatment group to calculate the odds ratio (OR) with its 95%CI. Data were pooled using the random-effects model, and the I² test was used to assess heterogeneity. All pooled statistics were subjected to double data entry to ensure accuracy in data entry. Heterogeneity was considered substantial if I² was >50%.[21] For quasi-experimental trials where statistical pooling was not possible, the findings have been presented in a narrative form.

Quality assessment

The methodological quality of individual studies was assessed independently by two reviewers using the Cochrane risk-of-bias tool for randomized trials (RoB 2),[22] RoB 2 cross-over trial checklist,[23] and the Risk Of Bias Non-Randomized Studies of Interventions (ROBINS-I).[24] Any discrepancies were resolved through discussion.

Results

Study selection

Following a systematic search, 553 studies were identified from databases, and 89 studies were retrieved from Google Scholar, hand searching, and grey literature. After removing duplicates (n = 155) and reviewing the titles and abstracts (n = 406), 81 papers were retrieved for potential inclusion. The full text could not be retrieved for seven studies. A review of the full texts resulted in a further 52 studies being excluded and 22 studies being included in the review [Figure 1]. The inter-rater reliability for the title and abstract screening and full-text screening was 0.61 and 0.65 (Cohen’s Kappa), respectively, indicating substantial agreement.

Figure 1.

PRISMA 2020 flowchart

Study characteristics

The 22 included studies comprised parallel-group randomized controlled trials (n = 7), cross-over randomized controlled trials (n = 2), parallel-group non-randomized trials (n = 10), and cross-over trials non-randomized trials (n = 3). Studies were undertaken in medical (12 studies, n = 2035), dentistry (3 studies, n = 239), nursing, (5 studies, n = 463), and pharmacy (2 studies, n = 730) students. The sample size in individual studies ranged from 40 to 582 [Table 1].

Table 1.

Characteristics of included studies

Study		Specialty		Country		Case-based learning		Alternate Learning		Alternate Method		Duration of Intervention		Study Design		Outcome assessed
Cendan et al. (2011)[29]		Medicine		United States		130		130		LBL		2 months, 2 hours per week		NRCT		TWC
Du et al. (2013)[35]		Dental		China		20		20		LBL		Not specified		RCT		KC, SDL, PB, TWC, SS
Lee et al. (2013)[47]		Medicine		Taiwan		36		34		LBL		3 days		NRCT		SDL, TC
Tayem et al. (2013)[30]		Medicine		Palestine		68		68		LBL		1 year		NRCT		CT, SDL, TWC, SS
Lee Chin et al. (2014)[31]		Pharmacy		Malaysia		174		174		SBL		10 weeks		Cross Over RCT		SDL, PB, CD, SS
Singhal et al. (2017)[32]		Medicine		India		50		50		LBL		90 Minutes		CrossOver NRCT		CT, SDL, TWC
Horne et al. (2017)[27]		Medicine		United Kingdom		57		57		LBL		16 hours		NRCT		KC
Maas et al. (2018)[28]		Medicine		United States		231		352		LBL		2 hours		NRCT		SS
Bi et al. (2019)[1]		Medicine		China		40		40		LBL		240 minutes		RCT		KC, CT, SDL, PB
Haley et al. (2020)[33]		Dental		United States		46		58		LBL		12 months		NRCT		KC, CT, PB
Alhazmi et al. (2020)[39]		Dental		Saudi Arabia		47		48		LBL		45 minutes		RCT		CT, SDL, CD, SS
Kaur et al. (2020)[46]		Medicine		India		46		46		LBL		2 weeks		Cross OverRCT		CT
Aluisio et al. (2016)[42]		Nursing		India		17		20 LBL 16 SBL		LBL, SBL		1 hour		RCT		KC
Dupuis et al. (2008)[38]		Pharmacy		US		131		251		LBL		2.5 hrs		NRCT		KC, TWC, SS
Li et al. (2019)[26]		Nursing		China		40		40		LBL		13.5 hrs		NRCT		CT
Lanfang Liu et al. (2020)[45]		Nursing		China		73		73		LBL		5 months		RCT		CT, SDL, TWC, CD, SS
Ma et al. (2016)[36]		Medicine		China		85		85		LBL		36 hours		Cross-Over NRCT		CT, SDL, PB, TWC
Raurell Torreda et al. (2015)[34]		Nursing		Spain		35		66		LBL		42 hours		NRCT		CT, SDL, TWC
Yoo et al. (2015)[44]		Nursing		South Korea		72		71		LBL		9 hours		NRCT		PB, TWC
Smits et al. (2012)[41]		Medicine		Netherlands		64		64		LBL		5 days		RCT		KC, SS
LR Shwartz et al. (2007)[40]		Medicine		United States		52		50		SBL		1 hour		RCT		CD
Sangam et al. (2021)[43]		Medicine		India		100		100		LBL		1 month		Cross over NRCT		KC

RCT- Randomized Controlled Trial, NRCT- Non-Randomized Trial, CT- Critical Thinking, KC- Knowledge and Comprehension, SDL- Self Directed Learning, PB- Problem-Solving, TWC- Team Work and Communication, CD- Clinical and Diagnostic, SS- Student Satisfaction

There was a wide variation in the CBL strategies adopted and the mode of delivery in the included studies. The duration of interventions varied from 45 minutes to 1 year. The CBL strategies included small-group and large-group learning[25,26,27,28] [Table 1] The number of participants in small-group learning ranged from 4 to 5, and in large-group learning ranged from 50 to 75. CBL also includes case discussions, case presentations,[1,25,29,30,31,32,33,34,35,36] subgroup discussions, and focus group discussions.[21,22,27,28,31,32,34,35,36,37]

Theoretical content was delivered as prerecorded lectures,[28] didactic lectures,[34] or by providing reading materials.[27,32,33,35,36,38,39] Case scenarios were also made available for discussion and analysis in multiple formats such as case vignettes[27,40] and electronic learning cases.[41] Self-assessment quizzes, faculty-led quizzes, pre-post-session quizzes, and open-book online quizzes were conducted to enhance the learning experience.[27,28,33,38] The alternate methods included traditional lecture-based learning (LBL) or simulation-based learning (SBL) [Table 1].

Outcomes were measured using various methods. Learning competencies were measured using multiple choice questions,[25,28,32,39,42,43] self-administered questionnaires,[30,36,41,44] objective structured clinical exam (OSCE),[34,40,45] and subject-based written exams.[1,29,31,33,35,38,46] Competency-specific tools such as problem-solving activity[33] and critical thinking inventory[26] were also used to measure learning competencies.

Student satisfaction was measured using online surveys,[29] self-administered questionnaires,[1,31,33,35,41,46] and 5-point Likert scale feedbacks.[27,32,45] Most of the surveys also had provision for open narrative comments[28] or open-ended questions.[32,47]

Outcome

Learning competencies

Critical thinking

Six studies compared CBL with LBL on critical thinking.[1,26,34,36,39,46] Pooled data involving four studies demonstrated that critical thinking scores were significantly higher among those who received CBL compared to those who received LBL (SMD: 0.75, 95%CI: 0.21–1.29; I² = 86%, P = .007).[26,34,36,46] Similarly, a significantly greater number of students reported having better critical thinking skills among the CBL group compared to the LBL group (OR: 4.67; 95%CI: 1.50–14.53; I² = 0%, P = 0.008)[1,43] [Table 2 and Supplementary File Figure S1 ^{(528.6KB, tif)} ].

Table 2.

Meta-analysis of learning competencies and satisfaction of case-based learning versus alternate learning methods

Outcome (Continuous)		Sample Size				Number of studies		Standard Mean Difference		95%CI		I 2
		CBL		LBL/SBL
Critical Thinking		206		237		Four[26,34,36,46]		0.75		(0.21, 1.29)		86%
Knowledge and Comprehension (Total)		552		675		Eight[1,29,32,35,38,41,42,43]		0.41		(0.20, 0.62)		65%
Knowledge and Comprehension (Randomized Controlled Trials)		141		144		Four[1,35,41,42]		0.58		(−0.00, 1.16)		81%
Knowledge and Comprehension (Non-Randomized trials)		411		531		Four[29,32,38,43]		0.36		(0.20, 0.52)		30%
Knowledge and Comprehension (Simulation-Based Learning)		101		190*		Two (3 datasets available)[31,42]		0.19		(−0.08, 0.46)		36%
Problem-Solving		177		176		Three[35,36,44]		0.27		(−0.02, 0.57)		44%
Self-Directed Learning (Total)		214		212		Four[35,36,45,47]		0.30		(0.10,0.49)		0%
Self-Directed Learning (Randomized Controlled Trials)		93		93		Two[35,45]		0.43		(0.14, 0.72)		0%
Self-Directed Learning (Non-Randomized trials)		121		119		Two[36,47]		0.20		(−0.06, 0.45)		0%
Teamwork and communication		248		276		Five[34,35,36,44,47]		0.24		(−0.19, 0.66)		82%
Student Satisfaction		141		141		Three[27,35,41]		0.50		(0.11, 0.88)		57%
CBL: Case-Based Learning, LBL: Lecture-Based Learning, SBL: Simulation-Based Learning. *Simulation-Based Learning is the alternative learning method adopted
Outcome (Dichotomous)		Sample Size				Number of Studies		Odds Ratio		95%CI		I 2
		CBL		LBL
Critical Thinking		87		88		Two[1,39]		4.67		(1.50, 14.53)		0%
Knowledge and Comprehension		76		88		Two[27,33]		02.74		(1.30, 5.77)		92%

CBL: Case-Based Learning, LBL: Lecture-Based Learning

Knowledge and comprehension

Twelve studies compared CBL with LBL on knowledge and comprehension.[1,27,29,31,32,33,35,38,41,42,43] A meta-analysis including eight studies demonstrated that there was no significant difference in knowledge and comprehension scores among those who received CBL compared to those who received LBL (SMD: 0.41; 95%CI: 0.20, 0.62; I² = 65%).[1,29,32,35,38,41,42,43] A sensitivity analysis was performed based on the study design, and no statistically significant subgroup effect was noticed [Table 2 and Supplementary File Figure S2a ^{(1.8MB, tif)} ]. In contrast, a significantly higher number of students reported having better knowledge and comprehension skills in the CBL group than in the LBL group in two studies[27,33] (OR: 2.74; 95%CI: 1.30, 5.77; I² = 92%, P < 0.001) [Table 2 and Supplementary File Figure S2b ^{(1.8MB, tif)} ].

Two studies compared CBL versus SBL on knowledge and comprehension.[31,42] Both studies reported significantly higher knowledge scores among students in the CBL group compared to the SBL group (SMD: 0.19; 95%CI: −0.08, 0.46) [Table 2 and Supplementary File Figure S2c ^{(1.8MB, tif)} ].

Self-directed learning

Five studies assessed self-directed learning.[1,26,35,36,45] Pooled data from four studies[26,35,36,45] demonstrated no significant difference in self-directed learning scores among those who received CBL compared to those who received LBL (SMD: 0.30; 95%CI: 0.10, 0.49). In contrast, one study reported that a significantly greater number of students in the CBL group reported self-study ability than those in the LBL group.[1] A subgroup analysis was performed based on study designs (RCT vs. NRCT) and did not demonstrate differences in self-directed learning between the groups [Table 2 and Supplementary File Figure S3 ^{(806.1KB, tif)} ].

Problem-solving

Three studies assessed the problem-solving ability of students.[35,36,44] Pooled data demonstrated that problem-solving ability was higher for the CBL group, but the difference was not statistically significant (SMD: 0.27, 95%CI: −0.02, 0.57; I² = 44%, P = 0.07) [Table 2 and Supplementary File Figure S4 ^{(264.8KB, tif)} ].

Teamwork and communication

Five studies evaluated teamwork and communication skills.[34,35,36,44,47] Pooled data from the five studies demonstrated significantly greater scores for teamwork and communication in the CBL group than in the LBL group (SMD: 0.24; 95%CI: −0.19, 0.66; I² = 82%) [Table 2 and Supplementary File Figure S5 ^{(218.5KB, tif)} ].

Clinical skill development

Three studies assessed clinical and diagnostic skill development among students.[31,45,43] Only one study compared CBL with LBL, where the former had significantly higher clinical skill competency.[45]

Student satisfaction

Student satisfaction was assessed in 12 studies, where 11 studies compared CBL with LBL[1,25,27,28,30,32,33,35,39,41,45]and one study compared CBL with SBL.[31] Of the 11 studies that compared CBL with LBL, nine reported student satisfaction to be higher among those in the CBL group. However, due to the paucity of data, a meta-analysis including only three studies[27,35,41] could be undertaken. The results demonstrated that students in the CBL group had significantly higher satisfaction scores compared to those in the LBL group (SMD: 0.50; 95%CI: 0.11, 0.88, I² = 57%). Two studies[35,41] reported no difference in student satisfaction between CBL and LBL groups. In the only study that compared CBL to SBL, students in the SBL group had higher satisfaction scores compared to the CBL group[31] [Table 2 and Supplementary File Figure S6 ^{(454.3KB, tif)} ].

Risk of bias within studies

For the seven randomized control trials, the risk of bias was low in two studies,[35,39] moderate in four studies,[1,40,42,45] and high in one study.[41] [Figure 2] Among the 13 non-randomized controlled studies, the risk of bias was low in two studies (15.38%),[32,47] low-to-moderate in nine studies (69.2%),[25,26,27,28,29,30,33,34,43] and moderate-to-high in two studies (15.38%).[36,44] [Table 3]. The risk of bias was low in both randomized cross-over trials [Supplementary File Table S5].

Figure 2.

Risk of Bias Randomized Controlled Trials

Table 3.

Risk of bias for non-randomized control trials

Study		Confounding bias		Selection bias		Bias in the classification of intervention		Bias due to departures from intervention		Bias due to missing data		Bias in the measurement of outcome		Bias in the selection of reported results		Overall Bias
Cendan et al. 2011[29]		Low		Low		Low		Low		Low		Moderate		Low		Low to Moderate
Lee et al. 2013[47]		Low		Low		Low		Low		Low		Low		Low		Low
Tayem et al. 2013[30]		Low		Low		Low		Low		Low		Moderate		Low		Low to Moderate
Singhal et al. 2017[32]		Low		Low		Low		Low		Low		Low		Low		Low
Horne et al. 2017[27]		Low		Low		Low		Low		Moderate		Moderate		Low		Low to Moderate
Maas et al. 2018[28]		Moderate		Low		Low		Low		Low		Low		Low		Low to Moderate
Haley et al. 2020[33]		Moderate		Low		Low		Low		Low		Moderate		Low		Low to Moderate
Dupuis et al. 2008[38]		Moderate		Moderate		Moderate		Low		Low		Low		Low		Low to Moderate
Li et al. 2019[26]		Moderate		Moderate		Moderate		Low		Low		Moderate		Low		Low to Moderate
Raurell Torreda et al. 2015[34]		Low		Low		Low		Low		Moderate		Low		Low		Low to Moderate
Yoo et al. 2015[44]		Moderate		High		Low		Moderate		Low		Low		Low		Moderate to High
Ma et al. 2016[36]		High		Moderate		Moderate		Moderate		Low		Low		Low		Moderate to High
Sangam et al. 2021[43]		Low		Low		Low		Low		Moderate		Low		Low		Low to Moderate

Table S5.

Risk of Bias of Cross-over trials

		Appropriate cross-over design		Randomized treatment order		Carry-over effect		Unbiased data		Allocation concealment		Blinding		Incomplete outcome data		Selective outcome reporting		Other Bias
LeeChin 2014		Low		Unclear		Unclear		Unclear		High		High		Low		Low		Low
Kaur 2020		Low		Unclear		Unclear		Unclear		High		High		High		Low		Low

Discussion

CBL is a pedagogical approach that aims to forge clear links between theoretical knowledge and clinical practice by engaging and motivating students. This review aimed to investigate the effectiveness of CBL versus alternate learning methods on (1) learning competencies, including critical thinking, knowledge and comprehension, self-directed learning, problem-solving, and clinical skill development; (2) teamwork and communication; and (3) student satisfaction among healthcare students. Following an extensive search, 22 studies were eligible for inclusion; however, meta-analysis was restricted due to heterogeneity between the studies, paucity of data, and the limited number of studies assessing the same outcome. To the best of our knowledge, this is the first review to quantify the learning outcomes of CBL, thus providing evidence of the effectiveness of this teaching method for health professionals. The major strength of the review is the rigor with which it was conducted and the inclusion of RCTs and non-RCTs.

The evidence from this review demonstrates that CBL significantly improved critical thinking, problem-solving, teamwork and communication skills, clinical skills development, and student satisfaction. The evidence of the benefit of CBL on knowledge and comprehension and self-directed learning remains inconclusive. These results are consistent with a previously published narrative review that investigated the effectiveness of CBL in health professional education.[5]

The improvements in critical thinking and problem-solving skills among students can be attributed to the characteristics of CBL, which include supplementation of theoretical knowledge with real-life cases that students would encounter in the clinical environment.[30,35] Consequently students’ understanding and learning were improved as the real-life cases provided a context for the theoretical concepts and encouraged critical thinking through action and problem-solving. In addition, CBL is based on adult learning and inquiry-based learning approaches, which promote deeper, active, and meaningful learning.[6] These methods used in CBL encourage students to raise more questions and make critical comments, thus fostering lateral thinking.[44] For example, CBL facilitates feedback, where students can discuss the issues with each other and the teacher, thus enhancing their critical thinking. Unlike traditional health care, contemporary health care involves a growing number of patients with multiple chronic and complex health conditions. Thus, delivery of health care requires healthcare practitioners to have critical thinking and problem-solving skills, grounded in reasoning and imagination. CBL provides students with skills in critical thinking, which can be used to problem-solve once they enter the clinical setting.[48]

The evidence of the benefit of CBL on knowledge and comprehension remains inconclusive. According to the Revised Bloom’s Taxonomy of cognitive skills, knowledge and comprehension are two lower levels of skills and are inherent in any course.[49] CBL requires advanced preparation by the learners and provides a more structured strategy for learning, thus enabling knowledge retention and comprehension. In addition, CBL requires the student to actively think, participate in classroom interaction, and discuss the relevant knowledge under the guidance of the teacher to help in the internalization of knowledge.[1] Given that CBL was a new form of teaching method, students could have been too shy to interact in the classroom even though they had a lot to share, resulting in the inconclusive effect of CBL on knowledge and comprehension. Creating a safe space, small group learning, and assigning conversation partners could be strategies to encourage students to participate in CBL.

The evidence relating to the effect of CBL on self-directed learning is also inconclusive. This could be due to the small number of studies assessing this outcome. Nevertheless, self-directed learning is vital in the health profession to keep abreast of the current literature and advances in health care. It can be argued that health professionals generally try to keep up to date with new knowledge; however, engaging in self-directed learning during their undergraduate program better prepares them to become lifelong learners.[30] In particular, the engagement and self-evaluation components of CBL promote self-directed learning.[1]

The results of this review demonstrated that students who received the CBL approach to learning developed significantly better teamwork and communication skills. This could be because CBL is generally a group activity requiring students to be actively involved in the sharing of opinions and interact with each other during group discussions. As a result, students learn teamwork in order to achieve a common goal. Students also develop active and passive communication skills to sensitively communicate with each other during discussions. In contemporary health care, teamwork and communication are essential skills in developing good work relationships[50] and for better patient outcomes.[30] CBL prepares students with skills in teamwork[27,30] and communication, which are essential skills for contemporary healthcare professionals.

Student satisfaction

The evidence from this review demonstrates that students who received CBL had higher satisfaction with their learning compared to those who received LBL. This could be because students receiving CBL are more actively engaged in their learning and thus do not lose attention in class compared to other passive teaching methods. For example, the didactic method, which is the most conventional and economical way of teaching a large group of students, is boring, causing attention lapses among students.[51] In addition, the real-life scenarios used in CBL could test the students’ clinical decision-making and increase their confidence, resulting in higher satisfaction with the teaching method. It could also be postulated that the structured and guided knowledge delivery method in CBL is preferred by students, leading to higher satisfaction. Based on the CBL strategies used, this method of teaching can not only be engaging but also fun and useful,[27] as well as boost the self-confidence of students,[52] resulting in student satisfaction. It has been well established that students attend class if they feel satisfied with the learning and teaching methods.[22] CBL has been demonstrated to improve student satisfaction through engagement and motivation and could result in improved attendance and higher academic achievement.[46]

Limitations

This review is not without limitations. First, inadequate reporting; heterogeneity in the nature, duration, and mode of delivery of the interventions; and the use of various non-validated assessment tools prevented the use of meta-analysis to pool the data. Second, there were a limited number of studies that compared CBL to other methods of teaching.

Implications for further research

Given the limitations of the included studies, further RCTs should ensure rigorous methodology and reporting, mainly adequate sample size, randomization, and the use of validated instruments for measuring outcomes. As critical thinking and communication are important skills for health professionals, the results found in this review should be replicated with other health professionals. In addition, trials should have a longer follow-up period to conclusively assess the potential effects of CBL on knowledge, comprehension, and critical thinking. Only one trial compared CBL with SBL; hence, further trials undertaking this comparison are warranted. In this review, the majority of the studies delivered CBL as a face-to-face teaching method. However, given the modern technology and advances in information technology, CBL can also be used for virtual online teaching and learning.[53] Therefore, trials investigating the effects of online delivery of CBL on learning outcomes are needed. All studies included in this review were conducted in single institutions; thus, there is a need for large multicenter trials to increase the generalizability of the results.

Conclusion

Based on the results of this review, CBL has been identified as a superior method of teaching as it significantly improves critical thinking, problem-solving, teamwork, and communication skills, and enhances clinical skills development and student satisfaction. However, more rigorous RCTs are needed to underpin the available evidence.

Data availability statement

The data used in this systematic review were obtained from publicly available sources, including published research articles and reports. All data sources are appropriately cited in the reference section of this review. No additional datasets or proprietary information were used in this study. Researchers interested in accessing the primary data used in the included studies should refer to the original publications and contact the respective authors or institutions for any specific data requests or inquiries.

Conflicts of interest

There are no conflicts of interest.

Supplementary files

Figure S1

Comparison of CBL vs. LBL for Critical Thinking (Continuous)

Figure S2

(a) Comparison of CBL vs. LBL for Knowledge and Comprehension (Continuous). (b) Comparison of CBL vs. LBL for Knowledge and Comprehension (Dichotomous). (c) Comparison of CBL vs. SBL for Knowledge and Comprehension (Continuous)

Figure S3

Comparison of CBL vs. LBL for Self-Directed Learning (Continuous)

Figure S4

Comparison of CBL vs. LBL for Problem Solving (Continuous)

Figure S5

Comparison of CBL vs. LBL for Teamwork and Communication (Continuous)

Figure S6

Comparison of CBL vs. LBL for Student Communication (Continuous)

Funding Statement

Nil.