Common use of Epidemiology Clause in Contracts

Epidemiology. Mild or severe hearing loss is not a rare disorder, its prevalence increasing with age from around one per 1000 at birth to 1.6 per 1000 in adolescence, and to 88 per 1000 at age 65. In this project we mainly focused on the group who were, or became, severely deaf or hard of hearing (DHH) at a young age. There is no linear correlation between how persons who are DHH function in daily life and their degree of hearing loss in decibels, or with the type of hearing aids (such as amplification and cochlear implant) they use. Their functioning depends on a complex blend of interacting internal and external factors. Internal factors vary per individual, e.g. cause of the hearing loss, time elapsed since hearing loss occurred, severity of hearing loss (mild, moderate or severe), progression of hearing loss over time, comorbidities, visual/intellectual and social functioning. External factors may vary as well. Important external factors are quality and duration of audiological, psychological and communication interventions, the availability of local and national facilities for DHH people, including education and mode of communication (spoken language, sign language or sign supported spoken language) used by parents and other carers. Various ways to categorize severity of hearing loss are described in the literature (chapter 2). In this thesis ‘DHH’ is used to describe anyone with any degree or type of hearing loss. The term ‘severe DHH’ is used to describe people who experience difficulties in understanding a spoken conversation without using visual support.