Supplementary Material for: Fifteen-Year Follow-Up of Stapedotomy Patients: Audiological Outcomes and Associated Factors in a Middle Income Country

<b><i>Objective:</i></b> To evaluate the short-term (postoperative), medium-term (5 years), and long-term (10 and 15 years) audiometric results of patients who underwent stapedotomy and to determine specific factors associated with better postoperative outcomes. <b><i>Methods:</i></b> This study is a retrospective case review of 486 ears with surgically confirmed stapes fixation who underwent microscopic small fenestra stapedotomy. Preoperative, postoperative, and medium- and long-term air conduction (AC), bone conduction (BC), and air-bone gap (ABG) were assessed. Postoperative factors associated with better postoperative outcomes were evaluated. <b><i>Results:</i></b> At 10- and 15-year follow-ups, ABG, AC, and BC were significantly deteriorated but clinically preserved in comparison with postoperative results. According to a multiple quantile regression, younger age was associated with better postoperative results at 0.25 kHz (<i>p</i> = 0.003) and 4 kHz (<i>p</i> = 0.028) and a smaller preoperative ABG was associated with better audiometric results at 0.25 kHz (<i>p</i> = 0.048), 0.5 kHz (<i>p</i> = 0.001), and 4 kHz (<i>p</i> = 0.001). In addition, younger age (<i>p</i> = 0.001 for AC and <i>p</i> &lt; 0.001 for BC) and preoperative AC PTA (<i>p</i> &lt; 0.001 for AC) were significantly associated with better postoperative AC and BC PTA. <b><i>Conclusions:</i></b> Stapedotomy surgery provides short-, medium-, and long-term hearing benefits in our studied cohort. ABG, AC, and BC thresholds obtained after the surgery are clinically preserved in 5-, 10-, and 15-year follow-ups, with an age-expected BC deterioration. Smaller preoperative ABG and younger age were positive predictors for better postoperative ABG. Future research should address long-term subjective and quality of life outcomes.