Hearing loss is a public health problem that affects billions of people worldwide. However, data on its prevalence – generally speaking, its frequency in the population – and on the use of hearing aids, remain imprecise. A new study by a research team from Inserm and Université Paris Cité at the Paris Cardiovascular Research Center (PARCC, Inserm unit 970), in collaboration with the Paris Hospitals Group AP-HP and Foch Hospital in Suresnes, shows for the first time that 25% of adults in France are affected by some form of hearing loss. Disabling hearing loss, which is more severe, is thought to affect 4% of adults. This prevalence varies with age and other factors (standard of living, noise exposure at work, cardiovascular diseases, etc.), which are described in the study. In addition, the scientists have found that hearing aids remain largely underused, especially among seniors. These findings, based on data from thousands of participants from the Constances cohort, have been published in JAMA Open Network.
Hearing loss affects around 1.5 billion people worldwide, with World Health Organization (WHO) projections suggesting an increase to 2.5 billion by the year 2050. This is a major public health problem, especially since hearing loss is associated with decreased quality of life, social isolation, and other health problems such as depression, cognitive decline, and dementia.
However, it is still difficult to fully understand the extent of the problem and to improve prevention and screening measures, because the data available on the exact prevalence of hearing loss, the characteristics of those affected, and the use of hearing aids are still scarce.
They are most often derived from studies with small and nonrepresentative samples of participants from which it is complicated to draw generalizations, and from self-reported, unmeasured hearing loss data.
In order to have more robust data which can be used to inform public policy, a research team from Inserm, Paris Public Hospitals Group AP-HP, Université Paris Cité and Foch Hospital assessed the prevalence of hearing loss in France. For this they used data from 186,460 volunteers from the Constances cohort, who are representative of the general adult population and in whom hearing loss was measured using hearing tests.
The Constances cohort
Constances is a large-scale French epidemiological cohort, composed of a representative sample of 220,000 adults aged 18 to 75 years at the time of their inclusion. The participants are asked to have a health check every four years and to complete an annual questionnaire. Each year, their data are matched with the French national health insurance databases. This large-scale cohort is supported by the National health insurance fund and financed by the Investments for the future program.
The data collected, which concern health, socio-professional characteristics, use of health care services, and biological, physiological, physical, and cognitive parameters, enable us to learn more about the determinants of many diseases.
The volunteers, aged 18 to 75 years, completed questionnaires on their demographic and socioeconomic characteristics, their medical history and that of their relatives, as well as their lifestyles. They also underwent a health examination, between 2012 and 2019, which included a hearing test.
The study authors analyzed the entirety of this data and found that 25% of the individuals in the study sample had hearing loss, with 4% of the sample affected by disabling hearing loss (see box below). In addition, this research found that little use is made of hearing aids. For example, only 37% of patients with disabling hearing loss were wearing one.
The term “hearing loss” is used to refer to a person who is unable to hear as well as someone with normal hearing, the threshold being 20 decibels (dB) of loss in the better ear.
“Disabling hearing loss” means a hearing loss greater than 35 decibels (dB) in the better ear.
Taking their interpretation further, the researchers then attempted to identify the factors associated with hearing loss. Their analyses suggest that older people, men, people with a high body mass index (BMI), people with diabetes, with cardiovascular risk factors, a history of depression, or exposed to noise at work had the highest likelihood of suffering from hearing loss.
Conversely, having a higher income or education level, living alone, or living in an urban area were associated with a lower likelihood of hearing loss.
Hearing aid use was particularly low among elderly people (who are proportionately more affected by disabling hearing loss), men, smokers, and those with a high BMI.
Improving our understanding of the prevalence of hearing loss and the profile of those it affects is very important if we are to better target patients who are at risk, in order to screen them, improve their care, and refine prevention measures.
“This is the first time in France that a study on the prevalence of hearing loss and the use of hearing aids has been conducted on such a large and representative sample of the country’s adult population. This allows us to establish a reliable picture and to provide keys to public decision-makers, even though effective solutions (such as hearing aids and cochlear implants) are available to manage this major health problem,” stress Quentin Lisan and Jean-Philippe Empana, who coordinated the study.
While France has recently passed a measure allowing the reimbursement of hearing aids by Social Security (which was not yet the case at the time the study was conducted), it would be interesting for future research to evaluate the efficacy of such an initiative in encouraging the use of hearing aids.
 Team 4: Integrative Epidemiology of Cardiovascular Disease