The natural history of subjective tinnitus in adults: A systematic review and meta-analysis of no-intervention periods in controlled trials

Objectives: Tinnitus is a prevalent condition, but little has been published regarding the natural history of the condition. One technique for evaluating the long-term progression of the disease is to examine what happens to participants in the no-intervention control arm of a clinical trial. The aim of this study was to examine no-intervention or waiting-list data reported in trials, in which participants on the active arm received any form of tinnitus intervention.

Data Sources: CINAHL, PsychINFO, EMBASE, ASSIA, PubMed, Web of Science, Science Direct, EBSCO Host, and Cochrane.

Methods: Inclusion criteria followed the PICOS principles: Participants, adults with tinnitus; Intervention, none; Control, any intervention for alleviating tinnitus; Outcomes, a measure assessing tinnitus symptoms using a multi-item patient-reported tinnitus questionnaire. Secondary outcome measures included multi-item patient-reported questionnaires of mood and health-related quality of life and measures that quantified change in tinnitus loudness; Study design, randomized controlled trials or observational studies utilizing a no-intervention or waiting-list control group. Data were extracted and standardized mean difference was calculated for each study to enable meta-analysis.

Results: The evidence strongly favored a statistically significant decrease in the impact of tinnitus over time, though there was significant heterogeneity and clinical significance cannot be interpreted. Outcome data regarding secondary measures did not demonstrate any clinically significant change.

Conclusions: Participants allocated to the no-intervention or waiting-list control arm of clinical trials for a tinnitus intervention show a small but significant improvement in self-reported measures of tinnitus with time; the clinical significance of this finding is unknown. There is, however, considerable variation across individuals. These findings support previous work and can cautiously be used when counseling patients.