OBJECTIVE: To investigate whether degree of asymmetric hearing impairment influences patient-reported outcome measures and objective hearing results in primary stapedotomy. STUDY DESIGN: Register study. SETTING: Data from the Swedish Quality Register for Otosclerosis Surgery consisting of 90% of stapes operations performed in Sweden. MAIN OUTCOME MEASURE: The 984 patients eligible for inclusion were categorized on the basis of preoperative hearing impairment: unilateral, bilateral asymmetric, or bilateral symmetric. Pure-tone audiometry and patient-reported outcome measures were analyzed, and Glasgow benefit plots were constructed. Ordinal logistics regression analyses were performed to adjust for factors influencing PROMs associated with degree of asymmetric hearing. RESULTS: Over 90% of patients across all groups reported improved or much improved hearing ability post-surgery. Ninety-five percent of patients who rated their hearing as worse or much worse after surgery had an air-conductive gain of <
20 dB PTA4. Individuals with unilateral hearing impairment were more likely to report lower satisfaction with hearing function and daily life activities after surgery compared with those with bilateral hearing impairment, especially bilateral symmetric hearing impairment. In terms of hearing function, the bilateral symmetric hearing impairment group showed a significant decrease in the log odds of reporting lower satisfaction with a coefficient of -0.71 (95% confidence interval, -1.13 to -0.33), whereas the bilateral asymmetric hearing impairment group showed a nonsignificant decrease with a coefficient of -0.14 (95% confidence interval, -0.41 to 0.14) compared with the unilateral hearing impairment group. Tinnitus was more frequent in those with unilateral hearing impairment. CONCLUSION: Those with preoperative unilateral hearing impairment were more likely to express lower satisfaction with the results, compared with patients with bilateral impairment. Our findings suggest that the degree of bilateral hearing impairment should be considered in preoperative counseling, to better align with patient expectations regarding the benefit of surgery. An estimated air-conductive gain of at least 20 dB PTA4 was favorable for patient satisfaction.