Procedure

In a first step, the students from each class were divided into two groups: comparison and experimental, with the latter further divided into three subgroups (Fig 2). For purposes of efficiency and to minimize wait times, the procedure was tested with the first class (public school - 3rd year) and then reviewed and revised. In that initial round, the comparison group was first brought into the classroom to complete the knowledge test without having seen any video, after which they left the room. Then, in sequence, each experimental group entered the room to view one video: Group A, video 1; Group B, video 2; Group C, video 3. The order of presentation of the videos was modified for each of the three groups (i.e., in the second group, Group A watched video 2, Group B watched video 3, etc.). Each group completed the knowledge test immediately after viewing their video and then vacated the room for the next group. After this trial run, the timing was modified for the remaining three classes. In these rounds, the three experimental groups each viewed the video assigned to them, without completing the knowledge test immediately afterward (Fig 3). After all three screenings had been completed, all the students—including the comparison group—were invited into the room to complete the knowledge test. Two versions of the test were distributed to the participants to ensure the integrity of the results. Distribution of the two versions was alternated to avoid the possibility of plagiarism.

Three focus groups were formed on a voluntary basis (Table 2), made up of Burkinabè university students between the ages of 20 and 25 years (n = 46). Only those who had not seen any video (comparison group) were recruited. In these groups, all three videos were screened, followed by a discussion lasting 45 to 75 minutes. Participants were first asked to indicate which video they preferred. The facilitator began by inviting those who had preferred the least popular video to speak, so they could express their opinions without being influenced by the rest of the group. This was followed by a group discussion based on the discussion grid presented above (see Appendix 2). Ten semi-structured interviews were also conducted (45–60 minutes each), using the same grid, with four instructors and six nurse volunteers (Table 3). These respondents were carefully recruited by the local research coordinator in Burkina Faso based on certain criteria such as being in contact with patients (possibly suffering from dengue fever) or knowing the health professionals' training.