Analysis of the Reasons for Poor Prognosis in Severe to Profound Sudden Sensorineural Hearing Loss: A Systematic Review and Meta-Analysis.

Objectives: Patients with severe to profound sudden sensorineural hearing loss (SSNHL) generally experience poorer hearing recovery; however, the associated risk factors have not been identified. This study synthesizes current evidence to explore prognostic risk factors in this patient group. Methods: Databases were systematically searched through PubMed, Embase, Web of Science, and the Cochrane Library, from their inception to 18 October 2025. Three researchers independently extracted and recorded patient information and relevant data from all selected studies. Any inconsistencies were clarified through discussion or by consulting a fourth researcher. Results: The study included 2632 patients from 15 articles published between 2002 and 2025 and evaluated 8 prognostic risk factors. The results showed that profound hearing loss (OR = 4.68; 95% CI: 3.57-6.13; p < 0.001) and vertigo (OR = 1.95; 95% CI: 1.28-2.98; p = 0.002) were correlated with poorer hearing recovery. Subgroup analyses based on different prognostic criteria confirmed the consistent impact of hearing loss severity on poor outcomes. The remaining 6 risk factors did not show statistically meaningful associations. Conclusions: Profound hearing loss and vertigo are significantly associated with poorer prognosis in patients with severe to profound SSNHL. These findings may help identify high-risk patients early and inform the design of personalized therapeutic approaches in clinical settings.