The 22-item Sino-Nasal Outcome Test (SNOT-22) is a validated, patient-reported outcomes measure used to assess chronic rhinosinusitis (CRS) symptom burden 1. This review aims to characterize international variation in SNOT-22 scores among patients undergoing endoscopic sinus surgery (ESS), offering insight into how CRS is experienced across different healthcare and cultural contexts. This review adhered to the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. A comprehensive search strategy developed with a research librarian was run in PubMed, Embase, and Web of Science. Articles published from inception to January 2, 2025 were collected and imported into the Covidence review software on the same date. Eligible studies were primary research articles reporting preoperative SNOT-22 scores in adult patients with CRS undergoing ESS from a single-country population. The exclusion criteria were study cohorts including patients with cystic fibrosis, primary ciliary dyskinesia, or eosinophilic granulomatosis with polyangiitis, as these represent distinct systemic etiologies of CRS; studies that restricted inclusion based on a minimum SNOT-22 or nasal polyp score; and studies that did not specify CRS diagnostic criteria. The extracted variables included study design, country, diagnostic criteria, number of participants, and pre- and postoperative SNOT-22 scores. Postoperative scores were collected within 3–6 months of surgery. The analysis included studies reporting mean SNOT-22 scores and standard deviations, with pooled means calculated using variance-weighted fixed-effects models. To minimize multiple comparisons, eight countries with the largest pooled sample sizes were selected for pairwise comparison utilizing Welch's t-tests with inverse variance weighting. As previously described, a minimal clinically important difference (MCID) of greater than 8.9 points indicated a clinically meaningful change in symptom burden 1. After deduplication, 1920 studies were screened. Of 753 studies selected for full-text review, 287 studies were selected for inclusion (Figure 1). Most were prospective cohort (n = 112, 39.0%) or cross-sectional (n = 106, 37.0%) in design (Table 1). The majority of studies used the European Position Paper on Rhinosinusitis and Nasal Polyps (n = 177, 61.7%) diagnostic criteria. Compared to the United States (M = 43.3), China had a lower preoperative SNOT-22 score by −14.9 points (M = 28.4, 95% CI −16.4, −13.4, p < 0.0001), and Italy by −15.2 points (M = 28.1, 95% CI −17.1, −13.3, p < 0.0001). India and Canada had higher preoperative scores by +11.4 points (M = 54.7, 95% CI 10.1, 12.7, p < 0.0001) and +13.4 points (M = 56.7, 95% CI 9.4, 17.3, p < 0.0001), respectively (Table 2). When comparing postoperative score improvement across countries, the United States showed a mean decrease of 19.9 points between pre- and postoperative scores. Italy showed a mean decrease of 8.0 points, which was 11.9 points less when compared to the United States (95% CI −18.4, −5.4, p < 0.0001). In contrast, Saudi Arabia had a mean decrease of 25.2 points, Canada of 34.2 points, and India of 48.6 points, with mean reductions of 5.2 points (95% CI 2.0, 8.5, p < 0.0001), 14.3 points (95% CI 7.0, 21.5, p < 0.0001), and 28.7 points more when compared to the United States, respectively. There was no significant difference in postoperative improvement in SNOT-22 scores between the United States and either China or Taiwan (Table 2). Our findings identified significant geographic variation in patient-reported symptom burden among patients undergoing surgery for CRS. The lower preoperative SNOT-22 scores observed in China align with prior studies demonstrating that Asian patients tend to avoid extreme values on Likert-type scales, a response pattern that narrows score distributions and attenuates measured postoperative improvements due to floor effects 2-4. Cultural norms around stoicism and minimizing burden to others may further suppress symptom reporting, particularly for subjective domains such as pain or emotional distress 5. Of note, the higher preoperative scores from Taiwan highlight the heterogeneity of Asian populations. These differences likely reflect a complex interplay between cultural influences, patient selection, healthcare access, and expectations for care. For example, Chinese patients have been shown to be less likely to pursue elective quality-of-life surgeries, including ESS and joint replacement 6, 7, which may reflect higher thresholds for surgical intervention and influence the composition of surgical cohorts. Our results caution against a uniform grouping of “Asian” patients in future studies due to the underlying diversity of the included populations. In contrast, higher preoperative SNOT-22 scores in Canada and India may reflect healthcare system dynamics. Patients in these countries often face prolonged wait times for non-emergent surgery, which may delay intervention until symptoms become more severe 8. The greater postoperative improvements observed in these countries may also reflect this, where patients with higher baseline symptom burdens may experience greater perceived benefit from surgery. Notably, with the exception of Italy, mean improvement for each country exceeded the MCID, suggesting clinically meaningful benefit at the population level that support the utility of ESS across diverse healthcare systems and cultural contexts. Regarding limitations, many studies were conducted at tertiary referral centers, potentially leading to an overestimation of symptom burden at the time of surgery. Differences in CRS phenotype across countries may contribute to variation in the reported SNOT-22 scores, and subgroup differences may be obscured within more heterogeneous national cohorts, such as the United States. Finally, surgical technique or extent of ESS performed may also contribute to variations in score improvement. There is increasing recognition that patient-reported outcomes are central to evaluating the quality and effectiveness of care. Among these, baseline SNOT-22 scores have emerged as strong predictors of postoperative improvement and risk of revision surgery 9, 10. Overall, the findings of this study reinforce the value of SNOT-22 as both a clinical tool and a benchmark for patient-centered outcomes assessment, while highlighting the importance of interpreting SNOT-22 data within the context of cultural norms and healthcare infrastructure. This study reports geographic variation in SNOT-22 scores among patients undergoing surgery for CRS, underscoring the influence of cultural, systemic, and clinical factors on patient-reported outcomes. These findings highlight the importance of context when comparing patient-reported outcomes across diverse settings. We thank research librarian Karin J. Saric, MLIS for providing their expertise in search strategy creation. This project was presented as an oral presentation at the ERS-IRS-ISIAN 2025 Congress, June 22–25, 2025, in Budapest, Hungary. The authors have nothing to report. The authors declare no conflicts of interest.
Gao et al. (Thu,) studied this question.