Interventions in the management of blood viscosity for idiopathic sudden sensorineural hearing loss: A meta-analysis

Aims and Objectives: To estimate the efficacy of interventions in the management of blood viscosity for idiopathic sudden sensorineural hearing loss (ISSNHL) using meta-analysis method. Materials and Methods: An extensive search for literature was performed to identify publications from 1966 to 2016 in Cochrane controlled clinical trials register online, Medline, EMBASE, BIOSIS Preview, Web of Science, China Knowledge Resource Integrated Database and Wanfang. Only randomized control trials (RCTs) with valid control groups were included in this study. Each trial was graded for methodological quality using a 6-point standard. Meta-analysis was performed to assess the efficacy of intervention in managing blood viscosity on hearing improvement (primary outcome), relief of tinnitus and vertigo (secondary outcomes) for ISSNHL. Tests for sensitivity, heterogeneity as well as publication bias were also performed to evaluate the validity of results. Results: Forty-nine RCTs with a total of 4978 patients were included in this meta-analysis. The overall odds ratio of all interventions was 3.12 (P < 0.01). Significant effect sizes were shown on fibrinogen reduction, plasmapheresis, and anticoagulation as well as hemodilution. The mean methodological score was 3.0. There was great homogeneity between studies. No evidence of publication bias was found. Sensitivity test showed reliability and robustness of the results. Conclusion: This meta-analysis provided evidence to support the effect of interventions that manage blood viscosity in the treatment of ISSNHL. There is a need for more high-quality RCTs in the future, especially for hemodilution, anticoagulation as well as plasmapheresis.