Association of Sudden Sensorineural Hearing Loss With Vertebrobasilar Insufficiency.

Importance Little is known about the association between sudden sensorineural hearing loss (SSNHL) and vertebrobasilar insufficiency (VBI). Objective To explore the association between SSNHL and VBI. Design, Setting, and Participants This investigation was a population-based, case-control study. Patients from January 1, 2000, to December 31, 2011, were retrospectively identified from the Taiwan National Health Insurance Research Database, which includes claims data on a random sample of 1 million people. Main Outcomes and Measures Using propensity score matching on age and sex, patients were stratified at a 1:4 ratio into a study group comprising 5304 patients with a diagnosis of SSNHL and a control group comprising 21 216 patients. Those with a diagnosis of VBI before the index date (the date each patient was diagnosed as having SSNHL) in both groups were then identified. A conditional logistic regression model was used to estimate the adjusted odds ratios (ORs) and 95% CIs as a measure of the association between SSNHL and VBI. Results The study cohort comprised 26 520 patients. Their mean (SD) age was 51.3 (17.2) years, and 47.1% (12 500 of 26 520) were female. Vertebrobasilar insufficiency was diagnosed before the index date in 0.5% (26 of 5304) of patients with SSNHL and in 0.2% (38 of 21 216) of controls without SSNHL. After adjusting for comorbid medical disorders, patients with SSNHL were more likely than controls to have had VBI (OR, 1.76; 95% CI, 1.02-3.04). There were no significant differences in the prevalence of VBI among male patients with SSNHL vs male controls (OR, 1.72; 95% CI, 0.87-3.40) or among female patients with SSNHL vs female controls (OR, 1.86; 95% CI, 0.76-4.59). Conclusions and Relevance Patients with VBI appear to be at increased risk of developing SSNHL. Further research is needed to investigate the association among the severity of VBI, the risk of SSNHL, and the pattern of the audiometric curve.