A cross-sectional survey was conducted among undergraduate medical students in Chiang Mai University, Thailand from March to May, 2013. The Faculty of Medicine of Chiang Mai University, situated in northern Thailand, is the first and largest medical school outside of Bangkok. Medical students in their first to sixth years were asked to complete the Index of Learning Styles (ILS) questionnaire during the orientation for the 2013-2014 academic year.

The ILS questionnaire has been used to assess students’ learning styles since 1988, is known to be a simple and easy-to-use tool, and is regarded as having wide applicability [1]. The instrument categorizes learning styles into four domains: first, the active/reflective domain distinguishes between preferring to process information actively through engagement in physical activity or discussion, as compared to processing information reflectively through introspection; second, the sensing/intuitive domain distinguishes between preferring to perceive information via sensory routes such as sight, sound, or physical sensation, versus the intuitive route that involves memories, ideas, or insights; third, the visual/verbal domain distinguishes between whether information is best perceived visually through pictures, diagrams, or demonstrations, or verbally through sounds, written and spoken words or formulas; and, fourth, the sequential/global domain evaluates whether a student progresses toward understanding sequentially, in a logical progression of small incremental steps, or globally, in a holistic manner involving large jumps. The ILS-Thai version, translated with permission, has a reliability coefficient (Cronbach’s alpha) of 0.55 [2]. The ILS is a 44-item questionnaire that asks the respondent to choose one of two endings to a sentence that focuses on some aspect of learning. The scoring for each domain is 1, 3, 5, 7, 9, and 11, with 1 and 3 showing a balance along the continuum, 5 and 7 showing a moderate preference for one end of the continuum, and 9 and 11 a strong preference for one end or the other. The learning style preference for each domain is thus treated as a three-category variable consisting of the two polarities of the learning style and a balanced category.

Since the questionnaire was completed during the orientation period of the new academic year, students entering their first year of medical school were excluded because they had not started undergraduate medical education. Each participant’s year in medical school was reclassified as a binary variable that could be either preclinical or clinical. Students entering their second, third, and fourth years of medical school were classified as preclinical students, as they had completed their first, second, and third year of medical school, respectively. Those entering their fifth and sixth years were classified as clinical students. The previous academic year’s grade point average (GPA) was obtained from registry records. The student’s GPA was used to create a binary variable for high academic achievement, which was defined as having a grade point average of 3.0 or higher (maximum, 4.0).

The demographic characteristics, learning styles, and grade point average of each student were identified. Differences in learning styles as well as differences according to each domain were analyzed separately. Differences in learning styles between preclinical and clinical students were tested using the chi-squared test. Stratifying the preclinical and clinical students, the association between each domain of learning styles and high academic achievement was analyzed using logistic regression, adjusting for sex. Each dimension of learning styles was treated as a continuum, and was therefore tested for linearity and departure from linearity using the likelihood ratio test. In order to test whether associations between learning styles and high academic achievement differed between preclinical and clinical students, an interaction term between learning style and year of study (preclinical or clinical) was added into the regression model. A significant interaction term would suggest that the association between learning style and high academic achievement differed between the preclinical and clinical students.

This study was approved by the Ethical Review Committee for Research in Human Subjects, Faculty of Medicine, Chiang Mai University. Informed consent was obtained from all participants.

Overall, the majority of students had a balanced learning style in the active/reflective (56.5%) and sensing/intuitive (70.3%) domains. In the visual/verbal domain, a similar proportion of students were found to prefer visual (44.5%) and balanced styles (44.1%). In the sequential/global domain, most students preferred the sequential learning style (60.7%) (Table 2). The active/reflective domain significantly differed between preclinical and clinical students (Table 3).

Adjusting for sex and year of study (preclinical or clinical), the visual/verbal domain and the sensing/intuitive domain showed no association with high academic achievement. Weak evidence suggested that the association between the active/reflective domain and high academic achievement differed depending on the year of study (P=0.05). A reflective learning style was associated with high academic achievement only in the preclinical years (Table 4). Among preclinical students, those with a reflective learning style were 2.23 times more likely than students with an active learning style to have a GPA of at least 3.0 (odds ratio [OR]=2.23, 95% confidence interval [CI]=1.08-4.64). However, this association was not observed among students in the clinical years of the curriculum. For the global/sequential domain, a sequential learning style was significantly associated with high academic achievement (P=0.04). Compared to students with a sequential learning style, students with a balanced learning style and a global learning style were 19% (OR=0.81, 95% CI=0.61-1.08) and 50% (OR=0.50, 95% CI =0.23-1.07) less likely to have high academic achievement, respectively (Table 4).

In our study, we found that students in the preclinical and clinical stages had significantly different learning styles in the active/reflective domain. Although the majority had a balanced learning style in this domain, preclinical students were more likely to have a reflective learning style than clinical. The influence of learning content, teaching methods, and assessments may explain why learning styles differed between preclinical and clinical students [3]. The preclinical curriculum focuses on basic knowledge of medical sciences, which involves numerous complex details. As a result, the teaching methods unavoidably involved didactic lectures [4]. In our setting, the teaching methods used for preclinical students included lectures, problem-based learning, self-directed learning, and written reports. Students could have been more likely to be passive and may have preferred to observe and think through theories, thus spending more time working alone to understand the content. In contrast, clinical students were more likely to have an active learning style. This may have been because the pattern of teaching methods employed during the clinical years involve clinical and community-based learning. The basic knowledge gained in the preclinical years is usually applied to medical conditions during the clinical years. Students are also required to learn new skills during the clinical years. Teaching methods that include practice with patients in real situations may also have promoted a more active learning style [5]. A similar difference in learning styles between preclinical and clinical students was also observed in a recent study from Spain [4]. Previous research, from various settings, has found that some learning styles, such as theoretical, reflective, and assimilative, were likewise more commonly found in preclinical students [6]. Due to an excessive workload, clinical students may also be less inclined to develop a deep learning or reflective approach compared to the preclinical students [7]. We did not find differences in the other three learning style domains (visual/verbal, sequential/global, and sensing/intuitive) between preclinical and clinical students. A study from Sri Lanka similarly found no differences in learning styles between first and sixth year medical students [5]. This indicates that some teaching methodologies and core concepts may be similar across the preclinical and clinical stages.

Our study found that a sequential learning style was associated with high academic achievement, compared to the balanced and global learning styles. A sequential learning style was common in our study population. A strategic learning approach, which shares similar characteristics with the sequential learning style, has also been commonly found among medical students in Asia [7]. Students must acquire a considerable amount of medical knowledge and skills throughout the course of their education. Approaching learning in a sequential manner can assist them to remember strategically and logically, consequently helping students to obtain better scores in examinations [8,9]. A reflective learning style was associated with higher academic achievement only in the preclinical years. This style seems to match well with the learning content and teaching methods of the preclinical years [10].

No associations between other learning style domains and high academic achievement were found. This was similar to other studies exploring associations among similar learning style domains and academic achievement [11]. Some domains of learning styles may not have been associated with high academic achievement for multiple reasons. First, each individual could have used a mixture of different learning styles across different domains [10]. Second, academic achievement as defined through GPA may not reflect the real-world performance of learning outcomes [12]. Furthermore, even in the same year, each subject experienced a variety of teaching methods and assessments, each suitable for different learning styles. Lastly, this study may have been underpowered to detect such associations.

The study had several limitations. Causal interpretations cannot be drawn between learning styles and high academic achievement due to its cross-sectional design; however, it is more likely that learning styles influence academic achievement. Due to cross-cultural issues, gender differences, and differences in the learning content, associations between learning styles and academic achievement may differ depending on the setting [13,14]. These issues should be further explored in future research. Using GPA as measurement of achievement may also limit the generalizability of this study to other populations, where different methods and standards of assessment may exist.

The findings of this study suggest that awareness of learning styles may be useful for both students and instructors. Knowing their own learning styles can help students to improve their engagement with various teaching and learning activities in the curriculum, and can promote the individual’s professional lifelong learning. No learning style is best, and students should be encouraged to use and adapt themselves to different styles in various learning situations, rather than using only their most preferred style [15]. The faculty should promote effective learning by encouraging students to be aware of their own learning styles and assisting them to adopt methods appropriate to their style [16]. Furthermore, the faculty should also help students develop other learning styles in order to adjust to different methods of teaching [4]. Specifically, students with a prominently global learning style should be assisted in building a more balanced and sequential style to help cope with the complexities and abundance of knowledge required to practice medicine [14]. Although no association was found between the active/reflective domain and GPA during the clinical years, a reflective learning style supports deep understanding, which is important to professional lifelong learning. Therefore, a reflective learning style should be encouraged by promoting reflective methods of engagement in clinical teaching. Knowing the learning style of the students can help staff and faculty to create more appropriate courses, which promotes flexibility in teaching methods, and to improve the variety of teaching resources in order to help students achieve their educational goals [4].

In conclusion, learning styles were found to differ between preclinical and clinical students, potentially due to different learning content and teaching methods. A sequential learning style was associated with higher academic achievement in both preclinical and clinical students. A reflective learning style was only associated with higher academic achievement in preclinical students. Students should be encouraged to know their own learning styles and develop flexibility in this regard, in order to improve their engagement with various and changing teaching methods across the undergraduate medical curriculum. Instructors are also encouraged to understand the different learning styles of their students and to provide a variety of teaching materials and resources that suit different learning styles, in order to help students achieve their educational goals.