Impact of Hybrid Learning on Students' Performance in Biomedical Sciences During COVID-19 Pandemic

Oussama Hefnawi, BS, is a fourth-year dental student at the Herman Ostrow School of Dentistry of USC. Conflict of Interest Disclosure: None reported.

Xi Chen, DPPD, MPA, is the academic program manager in the Office of Academic Affairs at the Herman Ostrow School of Dentistry of USC. Her work focuses on program management, academic proposal development and learning outcome assessments. Conflict of Interest Disclosure: None reported.

Mavash Navazesh, DMD, is executive associate dean for academic, faculty and student affairs and a professor of diagnostic sciences in the department of diagnostic sciences, anesthesia and emergency medicine at the Herman Ostrow School of Dentistry of USC. Conflict of Interest Disclosure: None reported.

ABSTRACT

Background: The COVID-19 pandemic forced educators to rapidly adopt hybrid distance-learning instructions.

Objective: This study compared in-person to hybrid instructional delivery methods for acquiring biomedical sciences knowledge and critical thinking skills of first- (D1) and second-year (D2) dental students at the Herman Ostrow School of Dentistry of USC fall trimester 2019 through fall 2020.

Methods: Participants were coded by instructional methods (in-person versus hybrid). Independent t tests were performed to compare overall biomedical course scores of two consecutive cohorts of students receiving different instructional methods. Chi-square analyses examined the relationship between letter grade distribution and instructional methods. Then, paired t tests further assessed performance of the same cohort of students between instructional methods on three subcomponent exams of course grades: multiple choice question (MCQ), computer-based objective test (COMBOT) and triple jump (T3). A survey on instructional methods was also incorporated. The study design including deidentified grades collection was approved by the institutional review board (IRB).

Results: Students’ overall course performance in biomedical sciences in D1 and D2 was similar between the two instructional delivery methods (⍴ [D1] < 0.05, n = 288; ⍴ [D2] < 0.05, n = 284). Student scores on MCQ, COMBOT and T3 exams from hybrid instructions were slightly higher than their scores from in-person instructions (⍴ [MCQ], ⍴ [COMBOT], ⍴ [T3] < 0.0001, n =144). Students (n = 144) preferred taking problem-based learning sessions (94%) and T3 exams (80%) via Zoom or Blackboard over in person.

Conclusion: A hybrid instructional method is effective for learning foundational biomedical knowledge and developing critical thinking skills and is preferred by dental students.

Keywords: COVID-19 pandemic, instructional delivery method, hybrid learning, biomedical sciences, integrated curriculum, dental education, learning outcomes, problem-based learning

__________

The COVID-19 pandemic has had an immense impact on all aspects of life including the education sector. In many cases, in-person learning halted, and students had to adapt to remote or distance learning. Dental students experienced many changes to their routine educational experiences including canceled direct patient care and the adaptation of virtual rotations, lectures and seminars due to safer-athome orders. The sudden necessity to switch from traditional to distance learning caused by the pandemic has led to a great deal of anxiety among dental students.[1] They experienced increasing stress and expressed concerns over their suffered clinical education.[2] Haridy et al. (2020) studied the viewpoint of dental faculty through responses from 212 dental educators. Among them, 135 agreed that there were negative implications of COVID-19 on all dental disciplines, and 123 thought these implications would last a long time and that an action plan was needed.[3] Deery (2020) reviewed the impact of COVID-19 on 67 dental schools in the United States.4 The author suggested that dental schools should incorporate sustainable adaptation of distance learning in curricula as well as learning assessments and teaching methodologies.[4] The profession of dentistry lacks preparedness in dealing with emergency crises; therefore, protocols should be put in place to better respond to potential future crises.[4,5]

According to the Commission on Dental Accreditation (CODA), dental schools must incorporate didactic and clinical technologies to support dental education.[6] Additionally, dental graduates should have the competency to apply in-depth biomedical knowledge in the provision of patient care.[6] To meet CODA standards and adhere to federal and local mandates for the prevention of COVID-19 spread, dental schools had to find creative methods to deliver the same quality education. A sundry of learning modalities including online, blended and hybrid were thus adopted by dental educators globally to overcome challenges put forth by the pandemic.[3–5,7–10]

Although hybrid learning or blended learning is not a new concept, it has become a popular focus of educational research in light of the pandemic. Amir et al. (2020) studied students’ perspective of classroom and online learning during the pandemic and found that dental students agreed that blended learning of the two delivery methods could be manageable and useful.[10] In a comprehensive literature review, Barabari and Moharamzadeh (2020) discussed virtual reality simulation for manual dexterity skills development in dentistry.[9]

Several studies reported that dental students’ performance and perception have been the same or improved with hybrid or blended learning as compared to conventional teaching methods.[11–13] Farah-Franco et al. (2020) used a preclinical online hybrid learning model and investigated its impact on dental student learning outcomes while looking at student and faculty feedback. Their hybrid curriculum consisted of an online didactic aspect (videos, audio, diagrams and an assessment question) and content reinforcing methods (collaborative group projects and application of the online didactic aspects). They compared data from five multidisciplinary courses (comprehensive care clinical dentistry), and a health sciences reasoning test was used to measure critical thinking. They found that dental student educational outcomes remained steady or were improved with the hybrid learning. Hybrid learning in this case promoted critical thinking, self-motivation and clinical preparedness.[11] A study investigated the impact of blended learning by having 253 fourth-year dental students undergoing the new curriculum and comparing it to the previous traditional method of teaching. Assessments used online and written exams, assignments, quizzes and online discussion forums.[12] Blended learning cohorts scored higher grade point averages and students’ perceptions were positive. Another study assessed blended learning in a preclinical endodontic course and reported that the studied cohort performed better root canal procedures than the traditional cohort.[13]

To our knowledge, the impact of hybrid learning on an integrated holistic biomedical sciences curriculum in dental school during the COVID-19 pandemic has not been examined yet. Therefore, we aimed to make a contribution through an assessment of student performance on biomedical sciences curriculum in its entirety with a large class size of 144 students per cohort. This study compared in-person to hybrid instructional delivery methods for students’ acquisition of foundational biomedical knowledge and critical thinking skills during the first (D1) and second (D2) year of dental school. The results may help to shape future instructional modalities in dental schools beyond the pandemic.

Methods: Context

In spring 2020, the University of Southern California (USC) and the Herman Ostrow School of Dentistry of USC had to quickly adapt to the pandemic circumstances and make a series of changes to teaching and learning (TABLE 1).

As shown in TABLE 1, didactic classes moved into an exclusive online mode immediately after the midterm exam week; therefore, the spring 2020 trimester was split in half between the in-person and hybrid instructional methods. While clinic and lab activities have gradually resumed since August 2020 to a limited operational capacity, the biomedical curriculum and its exams have remained fully online since spring 2020 at the dental school. Based on the context reviewed, the study selected the following four trimesters as the study period to compare student performance between the in-person and the hybrid instructional methods: fall 2019, spring 2020, summer 2020 and fall 2020 (TABLE 2).

Instructional Delivery Methods

The in-person instructional delivery method in this study refers to small-group learning with a faculty facilitator in the classroom twice per week. The hybrid instructional method in this study refers to an exclusive online pedagogy with no in-person physical meetings. Yet, the learning is interactive and collaborative, using mixed virtual instructional methods including Zoom sessions, Blackboard, a virtual learning management system, Osmosis, a video stream learning aid, chatrooms, online problem-based learning (PBL) cases and the online school library. These methods can be used synchronously or asynchronously.

Apart from adjustments to the instructional delivery method (inperson versus hybrid) and examination setting (classroom versus Zoom or Blackboard), there were no changes to the biomedical sciences curriculum content and sequence, coursework, faculty facilitators and grading criteria.

Study Design

Student participants (N = 428) were coded by the instructional method (inperson versus hybrid) they received in a trimester and class cohorts. Learning outcomes were measured through student performance on two comprehensive and integrated courses that build the biomedical sciences curriculum in D1 and D2 at the Herman Ostrow School of Dentistry of USC: Human Structure and Human Function.[15] The performance indicators used in this study are overall course score points, course letter grades and the two courses’ graded activities and subcomponent exams, including participation in problem-based learning (PBL) sessions, a multiple-choice questions (MCQ) exam, a computer-based objective test (COMBOT), a triple-jump exam (T3) and a problem-solving exam (P3).

Following a learner-centered curricular principle, performance indicators measure students’ acquisition and application of biomedical sciences knowledge. The PBL participation grades measure students’ learning, reasoning, teamwork and feedback skills demonstrated in the PBL case sessions. Each PBL group normally includes eight students and one faculty facilitator. For each hypothetic patient case, students are expected to work collaboratively to first identify the facts (what they know), establish a set of hypotheses (what they think) based upon these facts and then determine their learning needs (what they need to know) to evaluate their hypotheses. The MCQ and COMBOT exams are based on fundamental knowledge learned in PBL cases.

T3 and P3 exams assess students’ critical thinking skill development and application. A T3 exam functions as both a learning exercise and assessment that includes three steps: 1) draft an analysis of a hypothetical patient by identifying major problems and establish reasonable questions and hypotheses (one hour); 2) search scientific evidence to test hypotheses; and 3) on the next day, report findings and conclude whether the hypotheses should be accepted or rejected during a 30-minute oral presentation to two faculty evaluators.[16,17] In the P3 examination, students are required to review a hypothetical patient scenario, establish a list of differential diagnoses, list supporting evidence and identify a prioritized list of tests and procedures to help make a final diagnosis.

An overall course score is the sum of each graded component multiplied by its respective percentage assigned in the course syllabus (TABLE 1). The letter grades use the following scale: A = 90%-100%, B = 80%-89%, C = 70%-79% and F = 0-69%. The grading components of biomedical courses in D1 and D2 (TABLE 3) include PBL participation, MCQ, COMBOT, T3 (D1 only) and P3 (D2 only).

The relationship between instructional delivery methods and student performance was assessed twofold. First, the study compared the performance of two consecutive cohorts of dental students on the same curriculum, with one cohort receiving in-person instruction before the pandemic and the other cohort receiving hybrid instruction during the pandemic. Secondly, the study compared the performance of a same class cohort of dental students on biomedical courses taught in-person before the pandemic and then through hybrid instruction during the pandemic. The four comparisons of student performance on biomedical courses between instructional delivery methods are listed below.

Two-consecutive-cohort comparisons:

■ Overall course scores and distribution of letter grades in D1 trimester I. Cohort (inperson instruction) in fall 2019 versus Cohort (hybrid instruction) in fall 2020.

■ Overall course scores and distribution of letter grades in D2 trimester IV. Cohort (inperson instructions) in fall 2019 versus Cohort (hybrid instructions) in fall 2020.

Same-cohort comparisons:

■ Exam scores of MCQ, COMBOT and T3 earned by the same cohort of D1 students on inperson midterm exams versus hybrid final exams (via Zoom or Blackboard) in spring 2020.

■ Average scores of three inperson T3 exams versus average scores of three hybrid T3 exams (via Blackboard) earned by the same cohort of D1 students fall 2019 through summer 2020.

The study also incorporated a recent survey in spring 2021 to this cohort of dental students, who are now in their D2 year, about their preference of instructional and assessment methods in learning biomedical sciences (hybrid versus in person). This survey was part of the school’s routine outcomes assessment measures managed by the Ostrow School’s Office of Academic Affairs with the assistance of student leadership.

Data Collection

The study design and data collection were approved as coded-data research by the USC Institutional Review Board, #UP-21-00272. The grades of the biomedical courses in D1 (Human Structure I and Human Function I) and D2 (Human Structure II and Human Function II) from fall 2019 through fall 2020 were collected for the study. The deidentified grades were obtained from the grading database managed by the Office of Academic Affairs, which included overall course scores, letter grades and scores of PBL session participation, MCQ, COMBOT, T3 and P3 exams. Student participants were coded by the instructional delivery mode each cohort received in a given trimester: either in-person or hybrid. Student participants consisted of three class cohorts and 428 dental students at the Herman Ostrow School of Dentistry of USC. In the four comparisons discussed in this study, each cohort of student participants refers to all students in the class (N1 = 143, N2 = 144, N3 = 141). The N1 cohort had 144 students in trimester I but one student dropped during D1. Therefore, the number of students in the N1 cohort read 144 when referring to D1, but 143 when referring to D2.

Statistical Analysis

Independent t tests were performed to compare the averages of overall course scores of biomedical courses in D1 and D2 between in-person and hybrid instructional delivery methods. Chi-square analyses of independence, with 2 x 3 contingency tables, were performed to examine the relationship between the distribution of letter grades and instructional delivery methods. Because the biomedical curriculum was delivered in person during the first half of the spring 2020 trimester but through hybrid instructions for the second half of the trimester, paired t tests were performed to compare student performances on the midterm and final of the MCQ, COMBOT and T3 exams. Lastly, a paired t test was performed to compare students’ average performance on the three inperson T3 exams and three Blackboard T3 exams in D1. For all t tests and chi-square analyses in this study, the significant level (alpha) was .05.

Results

1. Students’ overall course performances of biomedical courses in D1 and D2 were similar between the two instructional delivery methods.

There was no significant difference in overall course scores of biomedical courses in D1 trimester I between two consecutive cohorts of dental students, with one cohort receiving in-person instructions in fall 2019 (N1 = 144) and the other cohort (N2 = 144) receiving hybrid instructions in fall 2020. (fIGure 1, ⍴-value = 0.235 > 0.05, t critical two-tail = 1.968, t stat = 1.191.)

The distributions of letter grades earned by the two consecutive class cohorts of students are listed in TABLE 4.

Chi-square analysis reported similar grades distributions between the in-person (N1 = 144) and hybrid (N2 = 144) instructional methods in D1 trimester 1 (fIGure 2). In other words, there was no significant relationship between instructional delivery methods and distribution of letter grades, at ⍺ = 0.05. (Result: χ2 [df = 2, n = 288] = 2.938, p > 0.05.) The independent t test and the chi-square analysis performed for two consecutive cohorts of dental students in D2 trimester IV suggested the same findings as the analyses in D1 trimester I. Student performance, by overall course scores and distribution of letter grades, were similar between the in-person (N1 = 143) and hybrid (N3 = 141) instructional delivery methods in D2 trimester IV. (Results: ⍴-value 0.153 > 0.05, t critical two-tail = 1.969, t stat = 1.434; χ2 [df = 2, n = 284] = 3.927, p > 0.05.)

2. Student scores on final MCQ, COMBOT and T3 exams from hybrid instructions were slightly higher than their performance from in-person instructions on the respective midterm MCQ, COMBOT and T3 exams in D1 trimester II, spring 2020 (TABLE 5, N1 = 144).

3. Students’ average performance on the three triple-jump (T3) exams given via Blackboard was better than their average performance on the other three T3 exams given in person in D1 (fIGure 3, N1 = 144).

The three in-person exams were the T3 midterm and final in fall 2019 and the T3 midterm in spring 2020. The other three Blackboard exams were the T3 final in spring 2020 and the midterm and final of T3 in summer 2020. The study calculated an individual student’s average score of three in-person exams and their average score of three Blackboard exams, and then used the two arrays of average scores to perform a paired t test (N1 = 144). (Results: ⍴-value 1.91568E-10 < 0.05), t critical onetail = 1.656, t stat = 6.728.)

As a supplementary note, the survey we mentioned earlier to this cohort of dental students (100% participation) reported 94% of students preferred the small-group PBL sessions remaining via Zoom. Students strongly agreed and/or agreed that they learned very well via Zoom (82%) and preferred taking T3 exams remotely via Zoom or Blackboard over in person (80%).

Discussion

The results of this study indicated that a hybrid instructional method is effective for learning fundamental knowledge of biomedical sciences and developing critical thinking skills. Despite the pandemic, students in both D1 and D2 receiving hybrid instruction were able to perform at a similar level as compared to their respectively immediate previous cohort receiving in-person instruction. Further, tests on the same cohort of D1 students reported slightly better performance on MCQ, COMBOT and T3 exams from hybrid instructions than in-person instructions. Our findings confirmed information reported in the literature that hybrid instruction in a digitally engaging learning environment can result in equal or enhanced student performances, and in many cases, students’ reactions were positive toward hybrid instructions.[11–13] The incorporated survey outcomes revealed learners’ preference of distance hybrid instructions for conducting problem-based learning sessions and remote exams, which added a student perspective to our findings.

This study’s contributions to the literature lie in the assessment of student performance on the PBL biomedical sciences curriculum in its entirety with a large class size of 144 students per cohort. Our integrated biomedical curriculum design makes it easy to conduct a holistic review on learning outcomes beyond a single subject such as anatomy and physiology. Other recent studies on dental students’ outcomes from hybrid or blended learning reported comparable outcomes; however, they mostly focused on skill development in preclinical (laboratory) and clinical sciences instead of PBL integrated biomedical sciences. Farah-Franco et al. (2020) found that the hybrid learning group either performed the same or better than the traditional group and showed increased self-motivation, independence and critical-thinking skills.[11] The sample size was approximately 70 students in each of the four groups of participants. Similarly, the study from Jordan on fourth-year dental students found that the blended learning group scored higher scores in assignments, quizzes and clinical assessments compared to their control counterparts (354 in the control group and 253 in the blended learning group).[12] Another study on 81 students’ performance in a preclinical endodontic course reported that the blended learning cohort performed better root canal procedures than the traditional cohort.[13]

This study reported here is among the early steps of a systematic plan to explore the effectiveness and sustainability of hybrid instructional methods at the Herman Ostrow School of Dentistry. We chose to first focus on biomedical sciences because, unlike virtual clinical rotations and the temporary halt of patient care forced by the pandemic, there were no interruptions in the biomedical sciences learning. Except for the change in the instructional delivery methods (in person versus hybrid), there were no changes to the biomedical sciences curriculum content and sequence, coursework, faculty facilitators and grading criteria. Our future focus will be on the assessments of students’ application of biomedical sciences knowledge learned and critical-thinking skills developed from hybrid instructions to their everyday practice of dentistry in the third and fourth years of dental school.

There were several limitations to our study. First, it focused exclusively on student performance indicators. Future studies on hybrid instructional methods should incorporate comprehensive student and faculty feedback, such as student motivation and faculty encouragement of student participation. Second, our problem-based learning pedagogy and learner-centered environment may potentially limit the generalizability of our results to other dental schools that have different types of pedagogy or learning philosophy. Third, it is worth noting that inequity in access to advanced technologies and school services in a more diverse and larger sample size may impact the hybrid learning outcomes differently. For example, at the Ostrow school, spaces with COVID-19 safety measures were provided for dental students who needed accommodations for Zoom exams or classes due to unstable internet or background noise at home. Frequent faculty calibration sessions were held for virtual teaching, proctoring exams and student counseling. Faculty and staff members from the offices of academic affairs, enterprise applications and facilities management made tremendous efforts to facilitate a smooth transition from in-person to distance hybrid learning. The availability of these supportive services could contribute to steady or better student performance and their positive experience of a hybrid instructional method.

Conclusion

A hybrid distance instructional method is effective for learning fundamental biomedical knowledge and developing critical-thinking skills for dental students. It is preferred by students over the traditional model.

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THE CORRESPONDING AUTHOR, Oussama Hefnawi, BS, can be reached at hefnawi@usc.edu.