Increased risk of sudden sensory neural hearing loss in patients with rheumatoid arthritis: a longitudinal follow-up study using a national sample cohort.

To evaluate the association between sudden sensorineural hearing loss (SSNHL) and rheumatoid arthritis (RA) among a national sample cohort from Korea. Data were collected from 2002 through 2013 for individuals aged ≥ 20 years in the Korean National Health Insurance Service (NHIS)-National Sample Cohort. We extracted the data from RA patients (n = 7619) and 1:4-matched controls (n = 30,476) and analyzed the occurrence of SSNHL. Matching was performed based on age, sex, income, region of residence, and medical history. RA was diagnosed based on International Classification of Disease-10 (ICD-10) codes (M05 or M06) and prescriptions for the antirheumatic drugs. SSNHL was diagnosed based on the relevant ICD-10 code (H912). Among the SSNHL participants, we included only those who had undergone an audiometry exam (claim codes: E6931-E6937, F6341-F6348) and received treatment with steroids. The crude and adjusted hazard ratios (HRs) were calculated using Cox-proportional hazard models, and the 95% confidence intervals (CIs) were determined. Subgroup analyses based on age and sex were also performed. The rate of SSNHL in the RA group (0.8% [62/7619]) was higher than that in the control group (0.6% [177/30,476], P = 0.021). The crude and adjusted HRs for SSNHL were 1.40 (95% CI = 1.05-1.87) and 1.39 (95% CI = 1.04-1.86), respectively, in the RA group (each P < 0.05). The relationship between RA and SSNHL was observed primarily in patients aged ≥ 50 years and men. The risk of SSNHL is higher in patients with RA.