The Effect of Cochlear Implantation on Tinnitus and Quality of Life: A Systematic Review and Meta-analysis

Objective: To ascertain the effect of cochlear implantation (CI) on tinnitus and quality of life. Databases Sources: PubMed, Scopus, Web of Science, and Cochrane Library were searched through August 21, 2020. Search strategies used a combination of subject headings (e.g., MeSH in PubMed) and keywords for the following two concepts: cochlear implantation and tinnitus. Study Selection: English articles reporting on pre-intervention tinnitus-related patient-reported outcome measures (e.g., Tinnitus Handicap Inventory [THI], Tinnitus Questionnaire [TQ], Visual Analogue Scale [VAS] for loudness) and quality of life measures (e.g., Nijmegen Cochlear Implantation Questionnaire [NCIQ] and Hospital Anxiety and Depression Scale [HADS]) for CI recipients were included. Data Extraction: Demographics, baseline, and follow-up data. Data Synthesis: Total of 27 articles reporting on 1,285 patients (mean age 54.5 years, range 14-81) were included. Meta-analysis of all tinnitus-related measures demonstrated improvement following implantation, with a mean difference of -23.2 [95% CI: -28.8 to -17.7], -12.6 [95% CI: -17.5 to -7.8], and -4.5 [95% CI: -5.5 to -3.4] (p < 0.05 for all) for THI, TQ, and VAS, respectively. NCIQ increased by 12.2 points [95% CI: 8.2-16.2] (p < 0.05), indicating improved quality of life among CI recipients. Psychological comorbidities were also ameliorated, as evidenced by reductions in HADS depression (-1.7 [95% CI: -2.4 to -0.9]) and anxiety (-1.3 [95% CI: -2.1 to -0.5]) (p < 0.05 for both) scores. Conclusion: Following CI, patients reported significant improvement in tinnitus via several validated questionnaires. Additional benefits include improved quality of life and reduction in psychological comorbidities.