A protocol for a meta-analysis of interventions to treat patients with sudden sensorineural hearing loss

Background

Hearing loss is one of the leading causes of disability worldwide, with greater than 20% of Canadian adults having measurable hearing loss in at least one ear. Patients with hearing loss experience impaired quality of life, and emotional and financial consequences that affect themselves and their families. Sudden sensorineural hearing loss (SSNHL) is a common but difficult to treat form of hearing loss that has a sudden onset of ≤ 72 h associated with various etiologies, with the majority of cases being idiopathic. Some patients may partially or completely recover hearing ability, but for 32 to 65% of patients whose hearing does not recover, feelings of social isolation elevate the risk of anxiety and depression. Hearing loss is also associated with poorer functional status, including difficulty with sound localization and hearing in noise. There exists a wide range of therapeutic options; however, treatment of idiopathic SSNHL is controversial because some patients recover spontaneously. The planned systematic review and network meta-analysis (NMA) will assess the relative effects of competing treatments for management of idiopathic SSNHL in adults.

Methods

Electronic search strategies were developed by an experienced medical information specialist in consultation with the review team. We will search MEDLINE, Embase, and the Cochrane Library with no date or language restrictions. Key clinical trial registries will also be searched for in-progress and completed trials. Two reviewers will independently screen the literature using pre-specified eligibility criteria, and assess the quality of included studies using the Cochrane Risk of Bias tool. Disagreements will be resolved through consensus or third party adjudication. Bayesian NMAs will be pursued to compare interventions in terms of their effects on hearing (including audiometric thresholds and speech recognition scores), extent of hearing recovery, quality of life, and incidence of harms (including vestibular dysfunction, incidence of infections, and withdrawals due to adverse events).

Discussion

This systematic review and NMA will offer new and informative evaluations of current therapies for SSNHL. The results will inform clinicians as to the relative benefits of the currently available interventions for managing this difficult condition, provide optimal clinical treatment strategies, establish evidence gaps, and identify promising treatments for evaluation in future trials.