Effectiveness of the flipped classroom on the development of self-directed learning in nursing education: a meta-analysis

A systematic search was conducted of literature in electronic databases without geographical restriction. The primary sources included PubMed, Embase, Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Central Register of Controlled Trials (CENTRAL), Wanfang Data, China National Knowledge Infrastructure (CNKI), and Chinese Science and Technology Periodical Database (VIP). The search was restricted from inception to June 2017 with the papers published in English and Chinese. The search terms were finally identified according to the relevant literature and reviews in Cochrane Library and Joanna Briggs Institute (JBI) Library, by researching and summarizing the titles, abstracts, and keywords. The MeSH terms and keywords of searching were used separately or in assembly. The search strategy for PubMed is shown in Table 1.

All results were downloaded as duplicates into Endnote X7 for checking and removing into different lines in accordance with the titles, abstracts, and keywords. The potential papers in the references were checked to identify appropriate studies satisfying the inclusion criteria that may have been excluded by the search strategy. Additionally, full texts of any indefinite papers were downloaded for review.

Two reviewers screened the titles and abstracts of all articles in the initial broad searching. Articles were selected for inclusion if: (1) a randomized controlled trial (RCT) or non-RCT comparative study; (2) subjects included higher vocational students, undergraduates, and postgraduates; (3) they used flipped teaching as an intervention; (4) include the outcome indicators for self-directed learning; and (5) reported the sample size of the subjects, the mean difference with 95% CI of self-directed learning scores. Articles were excluded if: (1) the same group of subjects also received other teaching methods; (2) without complete data; and (3) duplicate articles.

Two of the authors extracted and summarized independently the data from the included studies. Any disagreement was resolved by the adjudicative senior authors. The data were extracted in a pre-designed coding manual: the first authors, publication years, countries, study designs, subjects, sample size (intervention group and control group), curriculum, teaching model in

intervention and control groups, duration of intervention, outcome, and outcome measures.

The methodological quality of the studies was assessed as three levels including low bias, uncertain, and high bias by the authority of the Cochrane Handbook for Systematic Reviews of Intervention.³⁰ The list of seven-items checked on the Cochrane Handbook is as follows: adequacy of the generation of the allocation sequence, concealment of allocation, blinding participants and personnel, blinding outcome assessment, incomplete outcome data, selective outcome reporting, and other sources of bias. The assessment was independently conducted by two reviewers, and all disparities between them were resolved by consensus.

A meta-analysis of RCTs and quasi-experimental studies using Review Manager (RevMan) 5.3 software was conducted to explore differences between the intervention group and control group. The main strategy was to abstract and analyze the self-directing learning scores from different trials. Since the continuous outcomes which were expressed as a mean value and standard deviation measured by the scales, the standardized mean difference (SMD) of continuous outcomes was calculated from different scales and weighted mean differences (WMDs) was analyzed from the same scales. Chi-squared test and I² value were applied to estimate the influence of heterogeneity on the results of this meta-analysis. According to the Cochrane review guidelines, the random-effects models would be selected if severe heterogeneity was shown at I²>50%; otherwise, the fixed-effects models would be chosen. Moreover, sensitivity analysis was performed by deleting each study individually to appraise the consistency and quality of the results. Subgroup analysis was performed according to the scale dimension.

The flow diagram about the process of including and excluding studies is shown in Fig. 1. The search yielded 724 relevant articles, and 462 duplicated records were excluded. A further 413 studies were excluded after screening by reading the titles and abstracts. The full texts of 49 studies were assessed, while 29 studies were excluded due to following reasons: 23 articles contained outcome variables different from the interest of this review, two articles were reported in Korean language, and four articles were self-controlled studies. Of the 20 studies eligible for qualitative analysis, 12 were included in this meta-analysis

A description of the included studies is listed in Table 2. Twelve articles were included in the meta-analysis, and their total sample size was 1440 persons (755 in the intervention group and 685 in the control group). Ten of the included studies were completed in China and written in Chinese.^{9, 31, 32, 33, 34, 35, 36, 37, 38, 39} One study was carried out in Canada⁷ and one in Iran,⁸ both were written in English. The subjects of the included studies were nursing students. Among them, the participants of six studies were nursing undergraduates and those remaining were higher vocational nursing students. The sample size of included individual studies ranged from 30 to 193 participants, and the pooled sample size was 1440 (intervention group = 755 and control group = 685). Four studies were performed in nursing practice courses, and the others were medical theoretical lessons. The duration of intervention varied greatly, ranging from two periods to two semesters.

The scales for measuring outcomes of the included studies were as follows: SRL,^{9, 31, 38, 39, 40}ALC,^32,34 SDLRS,⁸ SDLRSNE,⁷ and some specially designed scales.33, 36, 41 The specially designed scales created by Chinese authors were not universally applied due to regional restrictions.

Fig. 2 and Fig. 3 show the differences in the risk of bias among the studies. Each included study was evaluated as a bias of high risk, low risk or unclear by using the assessment standards mentioned earlier. Of 12 included studies, the quality rating of one was A and of the others was B. Of nine RCTs and three quasi-experimental studies, four reported the random sequence generation in details, while three articles32, 36, 37 were concealed by drawing lots from a sealed box and one paper⁷ was a computerized random number generator. The allocation sequence of three studies8, 33, 35 was assigned by convenience sampling or the preference of the researchers, in which students were divided into experimental or control groups. Thus, ten studies did not report allocation concealment, which may cause selection bias. And for the remaining no details were mentioned. Considering the feature of the intervention, blinding of nursing students and teachers to the intervention is impracticable. However, ten studies reported the same teacher, courseduration, and teaching schedule in experimental or control groups. This was not likely to be influenced by lack of blinding procedures and awarded adequate for blinding. In addition, all studies described the results to prevent reporting bias. Beyond that, all studies reported that there were no significant difference between experimental and control groups about baseline data, which included age, sexuality, and academic records. At last, all included studies were free from “other bias” as defined in the Cochrane Handbook.

Figure 1

In accordance with the result of searching eight databases, this is the first meta-analysis about the impact of the FC method on self-directed learning of nursing students. This systematic review and meta-analysis examined how the FC improved the self-directed learning of nursing graduates and provided evidence supporting the effectiveness of this emerging teaching model on self-directed learning in nursing education.

There are several problems concerning methodological quality of included studies in the assessment process. Most comparative studies were limited by the random allocation of the intervention and control groups descripted on the standard of Cochrane Collaboration for Systematic Reviews of Interventions. Many studies were lacking adequacy of the random sequence generation and allocation concealment, which caused greater selection bias. Owing to no description of whether nursing students in experimental and control groups used the same teaching resources, such as teaching platforms and teachers, curriculum content, and duration, some studies did not record adequate details about the blinding of participants and personnel. However, data collection bythe teachers who were directly in teaching may be not feasible. Questionnaires were released together by the teachers at the end of the course and recovered after students have anonymously filled out.

Figure 4

The FC teaching model intervention of the included studies was conducted over differing lengths of time, from two periods to two semesters. Thus, the results of subgroup analysis according to the duration of intervention showed that all students in the experimental group from two periods to two semesters had higher overall self-directed learning scores. Heterogeneity of the half semester and two semester subgroups was zero percent, which meant homogeneity and the result of the included studies were reliable. Considering the few studies measuring the outcomes for two to four periods of intervention, more researches are needed to confirm the impact of the duration of FC teaching on self-directed learning development.

Among multifarious scales used to measure the effect of the FC teaching method on self-directed learning in this review, the SRL scale was the most frequently applied. Subgroup analysis showed that students in the FC had more active self-directed learning performance and motivation, self-learning ability, self-management skills, and information literacy compared with those in the traditional teaching. The FC teaching model was beneficial to learning motivation, because it was an internal power that could directly encourage nursing students to learn and an inward requirement that could strongly stimulate them to learn. The FC teaching model was of benefit to self-learning ability, because it helped students to adjust their psychological activity process of self-awareness, self-evaluation, self-development, self-education, and self-control during the course of learning. Higher scores in self-management skills reflected that learners in the FC could communicate with other classmates more positively and actively, cooperate with each other more harmoniously, and more willingly seek for help in the face of difficulties and obstacles. The reason might be that students must work at their own pace to master per-determined material with little or no help from an instructor.⁴² The FC teaching model was also beneficial to information literacy, because it improved the ability of nursing students to seek relevant information for themselves and evaluate how to utilize learning resources better.⁶ The pooled effect size for self-directed learning assessed by the SRL scale revealed that the FC was superior to the control group in the training of self-directed learning skills. According to the sensitivity analyses, the result is extremely stable.

Figure 5

Through the implementation of FC teaching, nursing students could acquire skills on how to apply information and resource and build capabilities and competencies by themselves rather than simply gain knowledge from books.⁴³ In addition to this, the chop and change fantasticality characteristic of nursing work demanded current nurses be equipped with problem-solving, critical thinking, and information literacy off their own bat. More specifically, the cultivation plan of FC teaching better satisfied the above requirements by way of various learning activities serving as a datum line for the FC teaching design, including mini-lectures, self-learning resources, and debates/discussion.⁶ Conversely, individual students in traditional lecture-based classrooms were less motivated to study by autonomous learning. Acting as empty vessels absorbing information passively, they did not energetically participate in processing learning information, developing further understanding, or translating monotonous knowledge into practice.⁴⁴ Therefore, the traditional classroom was not beneficial to explore initiative and self-directed learning.

In this systematic review and meta-analysis, there were several aspects worth strengthening as follows: a more rigorous and comprehensive search strategy was developed by the authors, who received training on professional evidence-based courses, which broadly included the MeSH and keywords of FC, self-directed learning,

and nursing education; the research was conducted on eight databases, and as many relevant articles were retrieved as possible; the quality of the included studies was moderate, and the overall sample size was adequate; most of the included studies well reported low risk on attrition bias and reporting bias, so the result could reflect the true effect of the FC model.

Meanwhile, findings of this paper should be interpreted in line with the following limitations: first, some potential studies have been possibly missed although the retrieval process was extensive and inclusive. Second, this review was limited by the small number of non-RCT studies that met the inclusion and quality criteria. The selection and extraction stages should be assessed independently by four reviewers to mitigate limitations. Lastly, due to the limitations of the RCT study type, many included studies ascertained self-directed learning by a diversity of measuring tools. The result was that statistical data analysis could not be reliably performed.

Clinical nursing practice in a dynamic health care environment requires more than knowledge just gained from books. Clinical nurses must also demonstrate essential self-directed learning skills such as self-learning ability, self-management, and self-engagement. Developing self-directed learning skills was influenced by personality responsibility and individual characteristics.⁴⁵ The evaluation of self-directed learning should focus on not only objective variables but also responsibility and characteristics. Whether the responsibility and characteristics of students were framed positively or negatively, it was often in keeping with the individuals’ learning experience in the context of the FC. Improving self-directed learning ability is a lengthy process; it permeates into the periods of classroom teaching, internship, and clinical work.⁴⁶ Furthermore, a comprehensive assessment system should be exploited to assess self-directed learning.