Correlation of Meri (Middle Ear Risk Index) Score with Surgical Outcome of Tympano-Mastoid Surgery in Patients with Chronic Otitis Media

Introduction: Chronic otitis media (COM) is a common cause of preventable hearing impairment requiring surgical intervention. The Middle Ear Risk Index (MERI) is used to assess disease severity and predict surgical outcomes. However, its prognostic reliability remains uncertain. This study aimed to evaluate the correlation between preoperative MERI scores and postoperative hearing improvement, anatomical outcomes and complications following tympano-mastoid surgery. Materials and Methods: This prospective observational study included 161 patients with COM undergoing tympano-mastoid surgery at a tertiary care teaching hospital in Kerala. Preoperative disease severity was assessed using MERI and classified as mild, moderate or severe. Hearing improvement was evaluated using postoperative air–bone gap (ABG) improvement. Anatomical outcomes and complications were assessed at one and three months. Statistical analysis included Pearson correlation, analysis of variance, chi-square tests and multivariable linear regression. Results: The mean age was 35.59 ± 14.74 years, and the mean MERI score was 3.53 ± 2.33. Mild, moderate and severe MERI categories comprised 60.9%, 24.8% and 14.3% of patients, respectively. Overall mean ABG improvement was 17.30 ± 10.55 dB. No significant correlation was observed between MERI score and ABG improvement (r = −0.023, p = 0.777). Hearing improvement was comparable across MERI categories (p = 0.910). Multivariable regression identified no independent predictors of hearing improvement. Three-month perforation occurred in 13.7% of patients and was not significantly associated with MERI severity (p = 0.366). Postoperative complications increased with MERI severity (p = 0.021), although this association requires cautious interpretation. Conclusion: Preoperative MERI scores did not significantly predict postoperative hearing improvement or three-month perforation. MERI may assist in disease severity assessment and risk stratification but should not be used independently to predict surgical success.