More than 740 million adults worldwide have had at least one symptom of tinnitus, and about 120 million are severely affected, according to a new report.
Tinnitus indicates the perception of a ringing, buzzing, whistling, rustling, or hissing noise in the ears or head when no corresponding external sounds are present. In its most severe form, which is associated with hearing loss, tinnitus can affect a patient's mental, emotional, and social health.
Researchers have lacked a clear indicator of how widespread the disorder is globally, as well as of who suffers the most serious symptoms.
"Our estimates indicate that, worldwide, 1 in 7 adults reported experiencing tinnitus," Carlotta Micaela Jarach, the lead study author and an epidemiologist at the Mario Negri Pharmacological Research Institute in Milan, Italy, told Medscape Medical News.
"Severe tinnitus has been found in about 2% of the population," she added.
The study was published in JAMA Neurology on August 8.
Association With Age
Jarach and colleagues from several European universities conducted an umbrella review, as well as a traditional systematic review and meta-analysis, to estimate the global prevalence and incidence of tinnitus, severe tinnitus, chronic tinnitus, and diagnosed tinnitus.
The investigators identified 767 publications. They analyzed the prevalence estimates from 83 of these articles and the incidence estimates from 12 articles.
The research team calculated that the pooled prevalence estimate of any tinnitus among adults was 14.4%; it ranged from 4.1% to 37.2% in the studies. The prevalence did not differ significantly based on the questions asked, whether patients had experienced tinnitus "for more than 5 minutes" or "during the last months." The pooled prevalence also did not differ significantly by sex; it was about 14.1% among men and 13.1% among women.
However, the pooled prevalence differed by age, with an estimate of about 13.6% among children and adolescents, which ranged from 8.5% to 21% in the studies. Among adults, the prevalence increased with age, starting around 9.7% for ages 18 to 44 years and rising to 13.7% among ages 45 to 64 years and 23.6% among ages 65 years and older.
The prevalence in adults appeared to differ significantly by continent, ranging from 5.2% in Africa to about 14% in Europe and North America and 21.9% in South America. However, the presence of tinnitus did not differ based on per-capita gross domestic product tertiles.
The pooled prevalence of severe tinnitus among adults was 2.3%, ranging from 0.5% to 12.6% among the studies. The severity of tinnitus among adults differed based on the tinnitus definition used. For those who were asked whether they were bothered by their tinnitus, the pooled prevalence of severe tinnitus was 6.4%, compared with about 3% for those asked about tinnitus severity based on a validated scale.
The pooled prevalence of severe tinnitus was 2.7% for children and adolescents, 0.4% for adults age 18 to 44 years, 2.7% for age 45 to 64 years, and 6.9% for age 65 years and older. The pooled prevalence was 2.3% for men and 2.7% for women.
The pooled prevalence of chronic tinnitus was 9.8%, and the pooled prevalence of diagnosed tinnitus was 3.4%.
A Common Disability
Converting the pooled prevalence estimates to absolute numbers, the researchers found that 749 million adults worldwide have tinnitus symptoms, and about 120 million adults have severe symptoms.
Based on six studies among adults, the pooled incidence rate of any tinnitus was 1164 per 100,000 person-years, which ranged from 479 to 2828 per 100,000 person-years. The pooled annual incidence rate approached 1%.
"Major health organizations, including the World Health Organization and the Global Burden of Disease, should give due weight to this disability, which appears to be present on par with other disabilities such as migraine, back pain, and hearing loss," senior study author Silvano Gallus, PhD, head of the Laboratory of Lifestyle Epidemiology at the Mario Negri Institute, told Medscape.
"We hope these results will help raise awareness of the problem so that research on effective treatments for tinnitus can be accelerated," he said.
No Approved Treatments
Tinnitus is considered a symptom of an underlying neurologic condition. To date, there are no approved drugs to treat tinnitus, though some therapies help people to live with the symptoms.
"Tinnitus is a life-changing experience for many. Learning effective management strategies in a timely fashion is the key to dealing with this difficult condition," Hashir Aazh, PhD, an audiologist who specializes in tinnitus and serves as a hearing research consultant for the audiology department with the Royal Surrey NHS Foundation Trust in the United Kingdom, told Medscape.
Aazh, who wasn't involved with this study, noted that the research team included a group of well-respected tinnitus researchers from several European countries. The systematic nature of the review minimized the risk of bias, he added, which should help clinicians, researchers, policymakers, and healthcare organizations to trust the data.
The findings line up with previous studies, Aazh said, which indicate that about 14% of the worldwide population experiences tinnitus at some point in life, and about 2% faces severe symptoms.
"It is important to understand how prevalent tinnitus is, because it can help healthcare organizations to secure resources and plan for developing diagnostic and therapy services that can support patients who are experiencing tinnitus," he said.
The study was supported by the AIT ONLUS Associazione Italiana Tinnitus. Gallus is partially supported by the Unification of Treatments and Interventions for Tinnitus Patients-UNITI project, which has received funding from the European Union's Horizon 2020 Research and Innovation Programme. Jarach and Gallus are partially supported by Tinnitus Genetic and Environmental Risks-TIGER project, which has also received funding from Horizon 2020. Aazh has disclosed no relevant financial relationships.
JAMA Neurol. Published online August 8, 2022. Full text
Carolyn Crist is a health and medical journalist who reports on the latest studies for Medscape, MDedge, and WebMD.
For more news about Italian research, visit Univadis Italy.
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Cite this: Carolyn Crist. Nearly 15% of Adults Worldwide Experience Tinnitus Symptoms - Medscape - Aug 17, 2022.