Figure 1. Surgical performance curves and funnel plots for operative time and postoperative complication.

Perforamnce curves suggested that mean operative time and recurrent laryngeal nerve palsy rate of surgeon A were lower than expected, while surgeon B performance was poorer than what was expected according to his experience (Fig. 1A and 1B). Funnel plots showed that inverse conclusions could be drawn when interpreting outcomes based on either a classical case-mix adjustment or a comprehensive performance adjustment method (i.e. considering both patient’s case-mix and surgeon’s experience). Surgeon A and B had lower and higher operative time, respectively, than the average based on performance adjustment (Fig. 1C). Similar trends were observed for nerve palsy rates (Fig. 1D).