Minimal Clinically Important Difference of the Standardized Cosmesis and Health Nasal Outcomes Survey

Background The minimal clinically important difference (MCID) for the Standardized Cosmesis and Health Nasal Outcomes Survey (SCHNOS) has not been determined. Objectives The authors sought to define the MCID for both domains of the SCHNOS questionnaire. Methods This prospective cohort study included patients who underwent functional, cosmetic, or combined rhinoplasty operation from June 2017 to June 2018 at a tertiary referral center. The average preoperative, postoperative, and change in scores were calculated for the nasal obstruction symptom evaluation scale (NOSE) and SCHNOS. Anchor-based MCIDs were estimated for both SCHNOS subscales to define change in obstruction and cosmesis perceived after the rhinoplasty. Results Eighty-seven patients (69% women, 31% males) with a mean age (standard deviation [SD]) of 38 years (14.7) at the time of surgery were included. The mean postoperative follow-up period (SD) was 145 days (117). The mean preoperative score (SD) for the NOSE was 52 (32), SCHNOS for nasal obstruction (SCHNOS-O) score was 55 (33), and SCHNOS for nasal cosmesis (SCHNOS-C) score was 50 (26) points. Postoperatively, the NOSE score was 23 (22), SCHNOS-O score was 24 (23), and SCHNOS-C score was 13 (18) points. The mean change in scores (SD) for NOSE, SCHNOS-O, and SCHNOS-C was -29 (37), -31 (38), and -37 (28), respectively. The calculated MCID for SCHNOS-O was 26 (16) and for SCHNOS-C was 22 (15) points. The MCID for NOSE was 24 (13) points. A sensitivity test for the patients with a follow-up >= 3 months showed only slightly different MCID estimates: 28 (17) for SCHNOS-O, 18 (13) for SCHNOS-C, and 24 (15) points for NOSE. Conclusions For the obstruction domain SCHNOS-O, the MCID was 28 points. For the cosmetic domain SCHNOS-C, the MCID was 18 points.