A systematic review has found that globally tinnitus affects around 740 million adults or around 14% of the world’s population
Tinnitus has been estimated to affect 14% of the world’s adult population or over 740 million people according to the findings of a systematic review and meta-analysis by a group of European researchers.
Tinnitus is defined as the perception of sound in the absence of a corresponding external acoustic stimulus and it best described as a symptom rather than a disease. Identified causes include noise trauma, metabolic diseases such as hypertension and diabetes, together with ear diseases including Meniere’s disease or lesions affecting the eighth cranial nerve. However, a problem for researchers trying to determine the prevalence of tinnitus, is the lack of a standard definition and in a previous meta-analysis of the prevalence, although 40 studies were identified, the authors noted that nearly half of the included studies had a high risk of bias and which therefore limited the generalisability of prevalence estimates.
In the present study, the European team sought to determine the global frequency of tinnitus using an initial umbrella review, which identifies published meta-analyses and a second traditional literature review of original publications. Combining the results, the researchers calculated a pooled estimate of the prevalence in both adults and children, together with an estimate of the prevalence of more severe tinnitus.
Overall tinnitus prevalence
A total of 113 eligible articles were identified although only 83 of these were used to estimate prevalence and 12 for incidence.
The pooled prevalence estimate for tinnitus in adults was 14.4% (95% CI 12.6 – 16.5%) although within the studies, estimates ranged from 4.1% to 37.2%. However, a problem identified in trying to assess prevalence was how studies had asked about tinnitus in different ways, leading to slight differences in prevalence. For example, when asked about ever experiencing tinnitus, the prevalence was 17.5% whereas only only 13.7% when asked if the condition had persisted for more than 5 minutes (13.7%) and slightly lower still, when assessed using a specific scale (9.3%).
Turning to children and adolescents, the estimated prevalence was 13.6% (95% CI 8.5 – 21%) and again there was a wide variation in prevalence (0.7% to 66.9%). There was also an age-related effect, for instance, the prevalence estimate was 13.7% among middle-aged adults and this rose to 23.6% in older adults, though there was little difference between the sexes (14.1% vs 13.1%, male vs female). There were also a significant geographical variation, with 5.2% of those in Africa affected and 21.9% of individuals from South America.
Finally, the researchers estimated that the pooled prevalence of severe tinnitus was 2.3% (95% CI 1.7 – 3.1%) and similar in children and adolescents (2.7%).
When converting the pooled prevalence into estimates of absolute numbers, the authors calculated that there were 749 (95% CI 655 – 858) million adults globally affected by tinnitus and 120 million with severe symptoms.
The authors concluded that their prevalence estimates of tinnitus were of a similar magnitude to the leading causes of years lived with disability such as hearing loss. They called for institutions such as the Global Burden of Disease to play a leading role to boost research on tinnitus and to improve the care of those affected.
Jarach CM et al. Global Prevalence and Incidence of Tinnitus: A Systematic Review and Meta-analysis JAMA Neurol 2022