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.