Subjective and HRV-based Data Assessing Supervising Surgeon Intraoperative Stress with Perceived Trainee Breast Surgery Skill Proficiency.

OBJECTIVE: To examine the association between perceived trainee technical skill proficiency and supervising surgeons' intraoperative stress using both subjective assessments and heart rate variability (HRV)-based physiological indicators and to explore whether this association differs according to the supervisor's operative role. DESIGN: Prospective observational study. After each procedure, supervisors completed structured questionnaires assessing subjective intraoperative stress and mood states. Trainee technical proficiency was evaluated by supervisors using a 10-item scale developed for breast surgery training. HRV was continuously recorded, and 2 indices were calculated: LF/HF↑% (percentage of operative time with LF/HF ratios exceeding the intraoperative mean) and RR↓% (percentage of RR intervals shorter than the preoperative baseline). Correlations were analyzed separately for each group. SETTING: Single academic institution. PARTICIPANTS: Supervising surgeons served either as primary surgeon (Group 1) or 1st assistant (Group 2) during breast surgeries involving trainees. RESULTS: A total of 123 procedures were analyzed (Group 1: n = 52, Group 2: n = 71). Trainee technical skill scores showed significant negative correlations with supervising surgeons' subjective stress scores in both groups (Group 1: ρ = -0.592, p < 0.001; Group 2: ρ = -0.706, p < 0.001). In contrast, no significant associations in either group were observed between trainee skill scores and HRV-derived indices. CONCLUSIONS: Supervising surgeons' perceptions of trainee technical proficiency were associated with self-perceived intraoperative stress in both primary and assistant roles, while HRV-based physiological markers showed no such associations. Subjective stress ratings may capture supervisory cognitive load and educational burden more sensitively than HRV metrics alone.