Using convenience sampling method, nursing undergraduates (class of 2022) were assigned to the intervention group (n = 37), while those from the 2021 cohort were assigned to the control group (n = 39). No statistically significant differences were observed between the two groups in terms of gender, age, grade point average (GPA), and critical thinking ability scores (P > 0.05).

2.2.1. Teaching Methods

Both groups used the same core textbook: the 7th edition of Fundamental Nursing edited by Li Xiaohan. The experimental teaching consisted of 64 credit hours, with the same instructors and identical total teaching hours for both groups. To minimize potential bias, the instructors were not involved in any of the experimental assessments, questionnaire surveys, or data analysis.

1) Control Group

The traditional teaching method was employed, where instructors first explained and demonstrated the operational procedures and key points. Students were then divided into groups of 10 - 15, with each group practicing under the guidance of one instructor. After every 30 credit hours of single-skill operation teaching, a 2-credit-hour case-based comprehensive teaching session was conducted, integrating three previously learned operational skills into one case scenario.

2) Intervention Group

Case-based teaching was jointly implemented by instructors and Master of Nursing Specialist (MNS) students.

a) Teaching Philosophy

Guided by the outcome-based education framework, the teaching focused on student development, integrating knowledge, skills, and values into case-based learning to develop students’ operational competence, clinical thinking, teamwork, and communication skills.

b) Teaching Preparation

i) GTA Recruitment and Training: During the first academic year, the MNS students from the class of 2022 received training about undergraduate fundamental nursing skills instruction through both the Advanced Nursing Practice curriculum and extracurricular programs, subsequently establishing one-to-one mentoring relationships with intervention group students.

ii) Case Database Development: The course instructors and MNS students collaboratively developed 80 teaching and assessment cases. Each case includes a scenario description, nursing problems identification, operational tasks, and 1~2 challenging situations. The developed cases were reviewed and then uploaded to the online platform.

iii) Restructuring of the teaching program：The original 64-credit-hour practical training was restructured into case-based learning workshops. Following every 6 credit hours of single-skill case instruction, a 2-credit-hour comprehensive case-based teaching session was conducted.

c) Teaching Process

i) Pre-class phase: instructors assigned MNS students according to the teaching schedule, ensuring a 1:3 supervisor-to-student ratio during sessions. One week before each class, faculty and postgraduate students worked together to conduct standardized patient training,

ii) In-class phase: the instructor systematically explained the operational procedures and key points based on the case, then conducted a demonstration. During the subsequent group practice session, MNS students took on a mentoring role, introducing challenging scenarios to guide nursing undergraduates’ hands-on practice. Students were required to analyze these simulated situations and make clinical decisions accordingly.

iii) Post-class phase: the nursing undergraduates uploaded reflective reports to the online platform, where both the instructor and MNS students provided online guidance.

2.2.2. Evaluation Methods

1) Midterm and final practical examination scores: Clinical instructors not involved in the course teaching conducted the assessments, with identical grading criteria applied to both the intervention and control groups.

2) Critical thinking ability: The Critical Thinking Disposition Inventory-Chinese Version (CTDI-CV), translated and revised by Peng MC [10], was used to assess critical thinking one week before and after the intervention. It comprises seven dimensions: truth-seeking, open-mindedness, analyticity, systematicity, critical thinking self-confidence, inquisitiveness, and cognitive maturity. Each dimension contains 10 items (70 items total), scored on a 6-point Likert scale. Scores for each dimension range from 10 to 60, with a maximum total score of 420. Higher scores indicate stronger critical thinking disposition. The scale demonstrated good reliability (Cronbach’s α = 0.90) and validity (CVI = 0.89).

3) Intervention group’s evaluation of the teaching reform: A self-designed “Teaching Reform Evaluation Questionnaire” was utilized for the survey. The initial draft of the questionnaire was developed based on literature review and team discussions, followed by evaluation by six experts with associate senior titles or higher and over 10 years of experience in nursing education or clinical practice. A pilot survey was then conducted, and the questionnaire was further revised based on identified limitations along with additional expert consultation. The final version consisted of 15 items. The scale-level content validity index was 0.91, and the item-level content validity indices ranged from 0.84 to 0.98. After the course, the questionnaire was distributed to students in the intervention group, with 37 questionnaires collected and 37 valid responses.

2.2.3. Data Analysis

The data were analyzed using independent samples t-tests in SPSS 26.0, with the significance level set at α = 0.05.

The intervention group showed significantly higher scores in both midterm (86.84 ± 3.35) and final (90.32 ± 2.78) individual practical assessments compared to the control group (P < 0.05). Notably, a statistically significant improvement was observed between midterm and final practical assessment scores within the intervention group (P < 0.05), whereas no significant difference was detected in the control group (P > 0.05). See Table 1 in detail.

Table 1. Comparison of midterm and final individual practical assessment scores between the two groups ( x ¯ ± s , score).

The intervention group achieved significantly higher scores on the final comprehensive assessment (86.86 ± 3.35) compared to the control group (P < 0.05). See Table 2 in detail.

Table 2. Comparison of final comprehensive assessment scores between the two groups ( x ¯ ± s , score).

The intervention group demonstrated significantly higher critical thinking scores (283.73 ± 20.91) compared to the control group upon course completion (P < 0.05). See Table 3 in detail.

Table 3. Comparison of post-course critical thinking scores between the two groups ( x ¯ ± s , score).

The percentage of students expressing positive evaluations ranged from 72.34% to 97.30% across the 15 items, with six items obtaining approval rates exceeding 80%. See Table 4 in detail.

Table 4. Intervention group students’ evaluation (n = 37).

The results of this study demonstrated that the intervention group achieved significantly higher midterm and final individual assessment scores compared to the control group (P < 0.05), which is consistent with the findings of Song YL [2]. The improvement in students’ operational skills may be attributed to the following three factors: 1) Case-based teaching employed realistic clinical scenarios, making learning content more vivid and concrete, thereby increasing students’ interest and participation. 2) The involvement of postgraduate teaching assistants effectively optimized the instructor-to-student ratio, ensuring each student received more timely and personalized guidance. 3) The similarities in age and experience between postgraduate assistants and undergraduate students fostered an effective near-peer learning atmosphere [8][9]. This equitable interaction persisted throughout the pre-class, in-class, and post-class phases, continuously reinforcing instructional effectiveness.

The post-intervention results demonstrated significantly greater improvement in critical thinking skills in the intervention group compared to the control group, consistent with findings reported by Huai PP [3]. The enhancement of critical thinking abilities may be explained through following mechanisms: 1) Both individual skill training and comprehensive training adopted case-based teaching, incorporating challenging scenarios such as changes in patient condition, incorrect medical orders, and nurse-patient communication conflicts within the cases，which created a “cognitive conflict” learning environment, effectively activating students’ metacognitive monitoring abilities, prompting them to continually adjust and optimize their thinking strategies. 2) Postgraduates served as “more capable peers” demonstrating and guiding thinking processes based on their advanced training and clinical experience. Undergraduate students actively observed and emulated these processes, mirroring the “cognitive exposure” mechanism.

As shown in Table 2, the intervention group achieved significantly higher comprehensive assessment scores than the control group. Questionnaire results indicated that over 80% of students perceived improvements in teamwork, communication and coordination, complex problem-solving abilities and so on. These outcomes may be attributed to the following implementations: 1) The course team expanded the comprehensive training from 4 to 16 class hours, providing students with enhanced opportunities for integrated skills practice, which may have contributed to the improved outcomes. 2) Triad-based scenario management requiring coordinated responses to emergent patient conditions (e.g., acute deterioration, medication errors), which necessitated precise role delegation and real-time interdisciplinary collaboration. 3) Iterative simulation cycles that progressively refined both cognitive skills (clinical decision-making under pressure) and behavioral competencies (conflict resolution, task synchronization). This aligned with Bandura’s social learning theory, where repeated, scaffolded practice in high-fidelity environments facilitated competency internalization.

The main limitation of this study lies in its use of a quasi-experimental design with non-randomized grouping. Although no statistically significant differences were found in gender, age, academic performance, and critical thinking skills between the two groups before the course, potential unmeasured confounding factors may still exist, such as teaching experience, instructional environment, students’ learning motivation and so on.