Objective <p>To examine the influence of sociodemographic and clinical variables on symptom burden in chronic rhinosinusitis without nasal polyps (CRSsNP), and to compare the sensitivity of three validated patient-reported outcome measures (PROMs)—NOSE-E, SNOT-22, and CRS-PRO—to these predictors. A planned sensitivity analysis was conducted to evaluate whether sleep-related item content influences associations with obstructive sleep apnea (OSA).</p> Study design <p>Cross-sectional analytical study.</p> Setting <p>Tertiary care hospital.</p> Methods <p>Fifty adults with CRSsNP completed the NOSE-E, SNOT-22, and CRS-PRO questionnaires. Sociodemographic and clinical variables, including age, sex, BMI, smoking status, allergic rhinitis, asthma, OSA, and prior nasal surgery, were recorded. Univariate and multivariable linear regressions were used to identify independent predictors for each PROM. A predefined sleep-free analysis excluded sleep- and fatigue-related items (NOSE-E item 4; SNOT-22 items 11–14; CRS-PRO items 9–10).</p> Results <p>Each PROM demonstrated a distinct predictor profile. In multivariable models, age and smoking independently predicted NOSE-E scores. Previous nasal surgery was the only independent predictor of SNOT-22 scores. Age and OSA were associated with CRS-PRO scores in the primary model; however, the OSA association disappeared in the sleep-free analysis, indicating that it was driven by sleep-related item content rather than sinonasal symptomatology. All models showed modest explanatory capacity (adjusted R² ≈ 0.10–0.19).</p> Conclusion <p>Systemic and lifestyle factors exert instrument-specific influences on symptom reporting in CRSsNP. The apparent association between OSA and CRS-PRO is mediated by sleep-related items, underscoring the importance of considering domain structure when selecting and interpreting PROMs. PROM-based evaluations in CRSsNP should incorporate domain-aware interpretation and caution in patients with sleep comorbidities.</p>