Twenty-two-item Sino-Nasal Outcome Test in a control population: a cross-sectional study and systematic review.

Background: The 22-item Sino-Nasal Outcome Test (SNOT-22) is a commonly utilized outcome measure for chronic rhinosinusitis (CRS). However, what constitutes a normal score remains poorly defined. The goal of this study was to evaluate SNOT-22 scores in a control population without CRS and perform a systematic review and meta-analysis of "normal" values.

Methods: Ninety-nine subjects without CRS were enrolled, with 95 fully completing the SNOT-22 questionnaire. Multivariable linear regression was used to determine whether demographic factors or medical comorbidities influence SNOT-22 scores in a population without CRS. A systematic literature search was performed, identifying studies that evaluated the SNOT-22 in a non-CRS population and estimates for SNOT-22 values were pooled.

Results: Thirty-six males and 59 females were included in the primary analysis with a mean age of 53.4 ± 17.3 years (range, 18-88 years). The mean SNOT-22 score was 16.4 ± 15.2. Asthma (p = 0.003) and depression (p = 0.002) were found to be independent predictors of higher SNOT-22 scores. Thirteen articles were identified in the literature search and 1 was provided via author correspondence, with 10 reporting sufficient data to be included in the meta-analysis. Weighted mean SNOT-22 score was 11 ± 9.4 (n = 1517). Our data differed significantly from published data (mean difference = 5.4; 95% confidence interval [CI], 3.4 to 7.5; p < 0.0001) likely owing to differences in comorbidities.

Conclusion: SNOT-22 scores vary in non-CRS populations depending upon the group queried. Asthma and depression are associated with higher SNOT-22 scores and should be considered when determining what constitutes a normal value.