Coronavirus Disease 2019 Knowledge Acquisition and Retention: a Flipped Classroom Based on Micro-learning Combined with Case-based Learning in Interns

Background: Since medical school affiliated hospitals suspended the internship rotation during Coronavirus Disease 2019 (COVID-19) pandemic period in China. Determining an effective and available approach for interns learning new disease knowledge becomes an important challenge in affiliated hospitals. We explored a blended learning approach, a flipped classroom based on micro-learning combined with CBL, in interns learning COVID-19 knowledge using prospective randomized study. Methods: : During COVID-19pandemic period in China, 74 final-year undergraduate interns who were scheduled to rotatein our affiliated hospital in academicyear 2019-2020were randomized to a flipped classroomor standard classroomwith 37 participants in each classroomgroup during a 120-minute live online COVID-19curriculum utilizing the same Network Teaching Platform provided by our university. The standard classroom group utilized traditional lecture, while the flipped classroom group applied micro-learningcombined with CBL.We compared the effect of both formats on COVID-19knowledge acquisition and the impact onclinical practice attitude. Results: : All 74 interns (100%) responded pretest, posttest and retention test, and completed the questionnaire online. Both formats significantlyimproved COVID-19 knowledge acquisitionat the conclusion of online COVID-19 curriculum.Interns’ knowledge test scores including total score and scores of five knowledge dimensions ofCOVID-19were significantly higher in the flipped classroomgroup than those in the standard classroomgroup ( P <0.05). Compared with interns in the standard classroom group, interns in theflipped classroomgroup performed better in retention test and hada significantly more positive clinical practice attitude( P <0.05 in all items). Conclusions: : A flipped classroom based on micro-learning combined with CBL showed greater effectiveness in COVID-19knowledge gainin final-year undergraduate interns and made their attitude toward clinical practice more positive.


Background
In December 2019, cases of serious illness causing pneumonia and death were rst reported in Wuhan, the capital of Hubei, China [1]. The World Health Organization (WHO) announced the o cial name of the disease as "coronavirus disease 2019 (COVID-19) ". Affected by this COVID-19 pandemic, schools in China including medical schools were closed during the national concern public health emergency. A liated hospitals also suspended the internship rotation.
However, one of the "quality standards" of current World Federation for Medical Education (WFME) Basic Medical Education (BME) is "continuous renewal", which requires the medical school should modi cation of the intended educational outcomes of the graduating students in accordance with documented needs of the environment they will enter. The modi cation might include clinical skills, public health training and involvement in patient care appropriate to responsibilities encountered upon graduation [2].
An a liated hospital is an integral part of the medical school and has the obligation and responsibility to undertake the teaching work of relevant clinical new knowledge. Knowledge learned in a liated hospital during the rotation period of the graduating students will provide supports for their lifelong learning and development. Determining an effective and available approach for interns learning new disease knowledge becomes an important challenge in a liated hospitals. Bene cial effects have been found in empirical studies of the ipped classroom approach [3], micro-learning [4] or case-based learning (CBL) [5] in some health profession educations including medical education.
We explored a blended learning approach, a ipped classroom based on micro-learning combined with CBL, in interns learning COVID-19 knowledge using prospective randomized study. We hypothesized that it would result in improved COVID-19 knowledge acquisition and retention, compared to a traditional mode.

Setting and Participants
We invited 74 nal-year undergraduate interns to participate this study. All participants were scheduled to rotate in our a liated hospital in academic year 2019-2020 and the progress of their internship was basically consistent. In the period of this study, they were suspended clinical practice and stayed at home because of the COVID-19 outbreak and pandemic.

Design
This was a prospective, controlled educational research study. Using the random number table, participants were divided into a ipped classroom or standard classroom with 37 participants in each classroom group. Figure 1 displays our research design and interventions.

Interventions
Both ipped classroom and standard classroom utilized the Network Teaching Platform built and provided by Shanghai University of Medicine and Health Sciences to carry out the instruction. Educational content of our COVID-19 curriculum was from "Program of Diagnosis and Treatment of COVID-19 (trial 7th edition)" issued by National Health Committee of the People's Republic of China [6]. The total lecture period was set up as 120 minutes long in each group. A teaching team consisted of 3 clinical teachers was responsible for both formats of 120-minute live online COVID-19 curriculum. To maintain consistency between the two groups, one teacher prepared all teaching materials and gave demonstration lectures for both formats. The other two teachers held the live online curriculum respectively at the same time during the intervention protocol. Materials were peer-reviewed by all teachers before live online instruction. The demonstration lecture using traditional teaching was recorded and decomposed into micro-lesson videos. A total of 12 videos were developed, each of which focused on one or two learning points and controlled within 10 minutes.
The standard classroom group utilized traditional lecture, while the ipped classroom group applied micro-learning combined with CBL. The standard classroom group's live online instruction consisted of 115-minute lecture given by clinical teacher on COVID-19 utilizing PowerPoint (PPT) slides, followed by 5 minutes for intern questions. The ipped classroom group's live online instruction consisted of 120-minute discussion on typical clinical cases of COVID-19 guided by the teacher including in-class interactive questions responded by interns.
One week before the live online COVID-19 curriculum, we uploaded lecture PPT slides or micro-lesson videos respectively for participants in standard classroom group or those in ipped classroom group to preview or self-study. A knowledge pretest was administered before classroom division, a knowledge posttest immediately at the conclusion of their online COVID-19 curriculum, a questionnaire following the posttest, and a retention test 2 months later. Pretest, posttest, retention test and questionnaire were delivered at the same time in the two groups on the Network Teaching Platform.

Data Collection
We collected the demographic characteristics of interns when the participants were invited. A 25-item multiple-choice knowledge test on ve dimensions of COVID-19 consisted of clinical manifestations, etiological detection methods, serological detection antibody titer characteristics, diagnostic criteria, and clinical typing was developed to measure the knowledge benchmark (pretest), acquisition (posttest) and knowledge retention (retention test). The total score of the knowledge test was set as 100 and composed of ve dimensions with 20 per dimension. For clarity, length, and di culty, we piloted the knowledge test on PGY-1 residents and faculty in primary care, respiratory, and infectious disease who did not participate in the study. The same test with varied question order was utilized for maintaining consistency among pretest, posttest and retention test. A questionnaire utilized Yes or No form including willingness to learn the knowledge of infectious diseases, practice hand hygiene, practice wearing self-protection, and return to internship rotation was developed to assess participants' attitudes toward clinical practice.

Outcomes and Analysis
We compared mean scores in pretest, posttest and retention test between ipped classroom group and standard classroom group using independent-samples t test. We performed paired samples t-test for each dimension knowledge and overall outcome, comparing the change in scores from pretest to posttest, and from posttest to retention test in the same group. A χ 2 test was used to compare attitudes toward clinical practice between the two groups.

Ethics and consent
This study was deemed exempt by the Institutional Review Board of Shanghai University of Medicine and Health Sciences A liated Zhoupu Hospital. The need for individual participant consent was waived.

Results
The response rate was 74 of 74 (100%) in all 3 knowledge tests and questionnaire. The average age of participants was 22.0 years, and 47.3% (35 of 74) were female. Neither age nor sex differed between the ipped classroom and standard classroom groups (Table 1). Mean total score (66.84 versus 67.08; t = .096; P = .924; Fig. 2) and each dimension knowledge score (all P ≥ .05; Table 2) in pretest were not signi cantly different between the two groups. The ipped classroom group performed signi cantly better than the standard classroom group for both posttest and retention test for either mean total score (all P < .001; Fig. 2) or ve dimensions scores (all P < .05; Table 2).

Attitudes toward Clinical Practice
Compared with participants in standard classroom group, participants in ipped classroom group had higher willingness to learn the knowledge of infectious diseases, practice hand hygiene, practice wearing self-protection, and return to internship rotation (all P < .05; Table 3).

Discussion
To our knowledge, this is the rst report of a prospective educational research study in a rotation suspended setting comparing the effects of a blended learning approach to a traditional lecture format, with regard to knowledge change on COVID-19 and attitude toward clinical practice. We found all interns had signi cant improvement in knowledge acquisition and retention compared with their knowledge benchmark, both mean total score and ve dimensions in the blended learning approach were higher than those in the standard group, and there was no signi cant different between the knowledge benchmark and retention within the standard group. This indicates that although both standard and blended learning approaches may improve the knowledge acquisition, the latter could make the interns better understand and consolidate the new disease knowledge. It might be based on better understanding of the new disease knowledge that interns in the blended learning group showed more positive practice attitude and better prepared them for clinical practice, such as showed higher willingness to learn the knowledge of infectious diseases, practice hand hygiene, practice wearing self-protection, and return to internship rotation. It is suggested that this blended learning approach could improve the learning initiative of interns in clinical practice, and thus help to indirectly improve the level of clinical practice in the future.
With the popularization and development of internet and computer technology, it is feasible and realistic to utilize this blended learning approach. In microlearning, the content for the learners is short and intrepid, promotes them to use the fragmentation time study independently. Recently, a review explored how micro-learning can be used to increase retention in learners on mobile applications [7]. In CBL, typical cases engage learners in active learning using course concepts to solve important problems [8]. Studies have shown CBL is a teaching tool used in a variety of medical elds using human cases to impart relevance and aid in connecting theory to practice [9]. The impact of CBL can reach from simple knowledge gains to changing patient care outcomes [5]. Jhala M et al. found CBL was useful for deep learning and emphasized its role in life long medical learning [10]. In the ipping classroom, the roles of teachers and learners are exchanged, learners completing self-study before class and classroom time is used for interactive learning and problem solving. Findings from a meta-analysis including six studies with only one prospective randomized study [11], suggest that ipped classroom may be associated with minimal gains in student knowledge compared to lecture [12]. There are several practical problems associated with ipped classroom, particularly prominent of which is more faculty time, faculty development, or resources to ensure to be effectively delivered [13,14,15]. We nished the video recording in the lecture preparation stage, and according to the knowledge units decomposed into micro-lesson videos. Generally, clinical teachers collect typical clinical cases conveniently and have the ability to guide classroom discussions on clinical cases. Therefore, we did not spend more faculty time, including teacher development and preparing learning resources in our study. In other words, this blended learning approach might be utilized at minimal cost.
The interns' clinical experience was insu cient and the bedside learning could not carry on during the rotation suspended period, so traditional lecture was inevitably di cult to achieve the ideal effect. The original intention of our study was to provide a feasible way for clinical teachers to teach interns learning new clinical knowledge effectively during a special period. A ipped classroom based on micro-learning combined with CBL might form a resultant force in our study, promoting the effect of COVID-19 knowledge acquisition and retention.
This study has limitations. It was a single center study, and was assessed only in nal-year undergraduate interns with high concerned topic, which limits generalizability. As a blended learning approach, our research results do not delineate whether main effect of this approach derived from ipped classroom, micro-learning or CBL. Additionally, both control and observation formats and all evaluations in our study were entirely online, which needs network communication and technology support. The datasets used during the current study are available from thecorresponding author on reasonable request. Knowledge Acquisition and Retention in Standard classroom versus Flipped Classroom for Overall Outcome a aGroup mean total scores on knowledge assessment test at baseline (pretest), immediately after the online COVID-19 curriculum (posttest), and 2 months later (retention test).The change in scores betweenbaseline and immediately after the curriculum represents knowledge acquisition and is signi cantly better using a ipped classroom. The change in scores from immediately after the intervention until end of 2-month follow-up represents knowledge retention and is signi cantly better using a ipped classroom.