Comparison of student perception and performance between case-based learning and lecture-based learning in a clinical laboratory immunology course

Introduction

According to Bloom’s cognitive taxonomy, higher orders of learning, above those of knowledge and comprehension, are crucial for clinical medicine training in medical education [1]. Clinical laboratory immunology (CLI), one of the major courses for medical students, is the study of application of immunological technology in clinical laboratory science [2]. For many years, the conventional (didactic lecture) teaching style, teacher-centered instruction has been dominant in higher education in China. In a traditional classroom, students become passive learners, or rather just recipients of teachers’ knowledge [3], [4]. Over the past few decades, attention has been paid to promoting active learning by adopting interactive student-centred approaches in undergraduate medical education, including problem-based learning (PBL) and case-based learning (CBL) [5], [6], [7].

PBL is an educational approach that is being implemented differently in different medical schools. PBL was first introduced by the McMasters University Medical School in Hamilton, Ontario, Canada in late 1960s by Howard Barrows and his colleagues as an educational format centered around the discussion and learning that emanates from a clinical based problem [8]. CBL, an educational method of PBL, provides students with a venue to relate content learned in the classroom to performance in professional practice [9], [10]. This process can be initiated as students solve problems that are posed in simulated real-life situations. CBL, an active learning process, helps learners be pro-active for their own study with the help from their peers, [6], [7], [9], [10]. As a result, teachers become facilitators, and students are far more independent and will learn from their own experience [11].

CBL is also a constructive learning paradigm, in which learners select and transform information, construct ideas, and make decisions based on their current or past knowledge [12], [13]. A case, as a trigger to initiate the learning, is generally written as a problem that provides the student with the history or background of a patient and the clinical situation of the patient including information such as vital signs, symptoms, and laboratory results [11]. In CBL, classroom instructors help students to solve diverse case-based problems that may occur in real-world situations, moving from abstract knowledge to practical applications [13], [14].

In our institute, the CLI course is mainly taught by means of didactic lectures including tutorials, and practical classes which mainly result in teacher-centered, unidirectional learning. The objectives of this study were to find the benefits of CBL in the teaching of the CLI course as compared to didactic lectures, and to evaluate the perceptions of participating students regarding CBL. The hypothesis was that students would have a positive attitude towards this course in response to the new instructional design we introduced.

Materials and methods

Study participants

A total of 85 senior students were enrolled in the CLI course during the autumn semester in 2012 year group (n=44), and in 2013 year group (n=41), respectively. All the students in each year were divided into two groups by sortition. One group was offered CBL, while the other was offered LBL as the teaching instrument. In the mid semester, the students undertook the first exam and then had to cross over from CBL to LBL (Figure 1). All participants were enrolled in a mandatory CLI course, which was delivered through traditional LBL and CBL. Moreover, participants who completed the questionnaire survey also filled out an informed consent form agreeing to participate in the study. Students in CBL group were briefed on the study purpose and process, and without any adverse effect on this course grade.

Figure 1:

A weekly schedule and curriculum designing in the CLI course.

(A) Schedule of the CBL group. (B) Schedule the LBL group. CLI, clinical laboratory immunology course.

Results

In a total of 85 students, there were no differences in gender proportion or mean age between the groups in Table 1 (p>0.05). Among the 85 students who participated in the survey, 81 (95.3%) students believed that the case scenarios were appropriate for the lecture topics, and 77 (90.6%) students agreed that CBL helped their learning skills, clinical problem-solving skills, understanding the difficult contents, and preparing for examinations. There were also 66 (77.6%) participants who thought that CBL contributed to understanding the CLI course learning objectives (Table 2).

The average sums of the perception scores in the CBL and LBL groups were 43.82±5.59 and 42.31±5.51 in Table 3, respectively, which showed no significant difference in students’ capability perceptions with the educational method between the CBL group and the LBL group (t=1.770, p=0.079). There were significantly different perception scores in the learning motivation (t=2.091, p=0.040), clinical reasoning ability (t=2.310, p=0.023), clinical problem-solving ability (t=2.337, p=0.022) and preparing for exams (t=2.043, p=0.044) between the groups (Table 3).

The majority of students (83.5%) believed that CBL contributed to improving their communication skills and ability to work as part of a team (Table 2). Compared with peer interaction perception scores in both groups there was a higher perception score in improving peer interaction in CBL group (4.25±0.83) than those in LBL group (4.15±0.89) (Table 3). However, there were no significant different perception score in both groups on improving peer interaction (t=–0.497, p=0.620).

The course test scores of the CBL group (81.20±5.17, range 60–96) were significantly higher (p=0.001) than those of the LBL group (76.67±7.17, range: 60–95) (Figure 2A). Fifty-four students (54/85=61%) achieved test scores higher than 80 in the CBL group, whilst this was the case for 23 students (23/85=28%) in the LBL group. The percentage of high test score (marks≥80) was significantly higher (p=0.001) in the CBL group than in the LBL group (Figure 2B).

Figure 2:

Comparison of clinical laboratory science students’ scores.

(A) Average marks. (B) The percentage of high test score (marks≥80) on CBL group (n=85) and LBL group (n=85) for the CLI course examinations (mean±SD).

Discussion

For the students of clinical laboratory science, it is very important to apply laboratory immunology knowledge into clinical practice [2]. Learning through CBL helps students to build on prior knowledge, integrate knowledge, and consider an application to future situations. While it is widely agreed upon that problem solving skills are essential in the practice of medicine, there is a wide spread skepticism to transform educational strategies in this direction [11], [15]. There are very few medical schools in China who have whole-heartedly embraced these approaches. Though we met the challenge of a traditional curricular framework, the CBL educational approach was first introduced in the CLI course for clinical laboratory science students in Lanzhou University, and the benefits of CBL in the teaching of this course were evaluated in 2012 and 2013.

Most of previous studies reported that CBL is a powerful educational strategy which improves students’ problem-solving abilities, independent learning skills and their ability to prepare for examinations [16], [17], [18], [19]. The findings of the current investigation are consistent with previous studies which examined the impact of CBL for clinical laboratory science students in the CLI course. Our study showed that 88.2% of students agreed that CBL provides a self-directed learning approach and helped them to learn the CLI course. CBL provides students with the opportunity to ask important analytical questions, consider various responses, and argue for or against various situations [13], [20], [21]. Our study data shows that 90.6% of students stated that CBL improved their clinical problem-solving skills, learning skills and helped them to better prepare for examinations, as well as improved their understanding of the subject matter and helped them to develop their clinical thinking in making their own diagnosis. As CBL focuses on real-life case problems, it is a potentially powerful method for training students’ ability in the CLI course. The cases presented using CBL enabled students to integrate and apply their developing clinical knowledge, as well as to reflect on complex situations, as opposed to performing clearly defined, predetermined tasks [20]. In addition, CBL encourages students to actively create their own knowledge and independently develop solutions, rather than refer to the knowledge imparted to them by educators or textbooks for problem solving [20]. This would promote the motivation to learn and help in their mastery of knowledge of the CLI course.

Although, CBL has been documented in the past as an effective teaching method to enhance the capability of medical students [16], [17], [18], [19], [22], few studies have been carried out to evaluate the effectiveness of CBL in the CLI course for clinical laboratory science students in China. The present study is the first step in curriculum innovation in the CLI course. To fully appreciate CBL, prospective follow-up studies are needed to monitor students’ progress. The present study only surveyed the students’ perceptions of CBL and LBL education. As compared to the LBL group, there was a significant increase of perception score in learning motivation (p=0.040), clinical reasoning ability (p=0.023), clinical problem-solving ability (p=0.022) and preparing for exams (p=0.044) in the CBL group. Our study data shows the CBL approach would help clinical laboratory science students improve their learning motivation, and problem solving abilities, as well as help them in the long-term retention of the CLI knowledge in the study, which in turn helped them to preform better in their examination. Therefore, the introduction of the CBL educational strategy would not only help the students gain requisite knowledge in the CLI course but also enhance their analytic and problem-solving skills.

Several limitations pertaining to this study must be considered when interpreting the findings. First, this study is limited in the sample size. Only 85 students were involved in this study from Lanzhou university during 2 years. This may not fully allow for generalizing the findings to the general population of clinical laboratory science students. Second, the instrument utilized to assess students’ perceptions was only designed to be administered on a single occasion at the end of this course, rather than assessing students’ perceptions on each separate unit and comparing the results. A multi-stage assessment of changes in student perceptions would have been more reliable for measuring student attitudes towards course restructuring. The final limitation was that we did not consider the student’s attitude in the current course and learning styles such as interactive or passive.

Conclusions

This pilot study was the first step of curriculum innovation in the CLI course. The overall positive response from the students confirms that CBL is a more effective teaching strategy and educational mode as compared to LBL in the CLI course.