Prevalence of hearing loss in Northern and Southern Germany.

ABSTRACT

BACKGROUND: The HÖRSTAT study conducted in Northwest Germany found hearing impairment in approximately 16% of adults when applying the World Health Organization (WHO) criterion. However, the robustness of extrapolations to a national level might be questioned, as the epidemiological data were collected on a regional level. METHODS: Independently from HÖRSTAT, the "Hearing in Germany" study examined adult hearing in Aalen, a town located in Southwest Germany. Both cross-sectional studies were based on stratified random samples from the general population. The average pure-tone threshold shift at 0.5, 1, 2, and 4 kHz (PTA4), the prevalence of hearing impairment (WHO criterion PTA4 in the better ear >25), and hearing aid uptake were compared. Data from the Aalen and HÖRSTAT studies were pooled (n = 3105) to extrapolate to the prevalence and the degree of hearing impairment for the years 2015, 2020, and 2025. RESULTS: Both studies yielded very similar results for PTA4. Weighted for official population statistics, the prevalence of hearing impairment according to the WHO criterion is 16.2% in adults, thus affecting 11.1 million persons in Germany. Owing to demographic changes, the prevalence is expected to increase in the medium term by around 1% per 5­year period. With a similar degree of hearing loss, hearing aid provision differs from place to place. CONCLUSION: When adjusted for gender and age to the European Standard Population, the prevalence of hearing impairment observed both in HÖRSTAT and the Aalen sample is considerably lower than reported for international studies. Since the analysis refers to cross-sectional data only, possible cohort effects are not considered in the prevalence projection.