Health care utilization and adults who are deaf: Relationship with age at onset of deafness

Health Services Research, Feb, 2002 by Steven Barnett, Peter Franks

In 1990 and 1991, the NHIS core questionnaire included questions related to hearing ability in the Hearing Supplement. People were identified as having hearing loss using three screening questions. For people with hearing loss, the supplement included two scales to rate hearing ability, as well as questions regarding the age at onset of hearing loss. In our analyses, the responses to these questions were used to define the study populations.

One hearing scale used was the self-rated scale (SRS). People rate the hearing ability of each ear without the use of hearing aids on a four-point scale, ranging from "good" to "deaf." For people older than 3 years of age, a second scale, the Gallaudet Hearing Scale (GHS), was also administered. This five-point scale rates how well a person can usually hear and understand speech without the use of hearing aids, ranging from the "ability to hear and understand whispered speech" to the "inability to hear or understand any speech."

For those with hearing difficulties, respondents were asked to identify the age at which the hearing problems began or the age at which they became deaf, as well as the age range for the onset of hearing trouble or deafness (before or after the 19th birthday and before or after the 3rd birthday).

In this study, deafness is defined using criteria established in previous demographic analyses (Gentile 1975; Ries 1994). Individuals are defined as deaf if they (1) indicated on the SRS that they at least "had a lot of trouble hearing" in both ears (a SRS score of 3 or greater in each ear) or (2) indicated on the SRS that, at best, they had "a little trouble hearing" in their better ear and indicated on the GHS that they could not hear and understand any speech (a SRS score of 2 or more in each ear and a GHS score of 5). The members of the resulting "deaf study population" have bilateral hearing loss that interferes with understanding speech.

For analyses in this study, the deaf study population is subdivided by age and age at onset of hearing loss. Because children access the health care system through their parents or other adults, only data on adults (19 years and older) were analyzed. Within the deaf community, age at onset of hearing loss often predicts communication mode and social group (Benderly 1980). The relative frequencies at different ages of hearing loss onset are illustrated in a histogram of the responses of deaf adults to the NHIS question regarding the exact age at onset of hearing loss (n = 2,449; Figure 1). Two peaks are evident, one before the age of 3 and a second after the age of 60. We divided the deaf study population data into two subpopulations based on whether the hearing loss is prelingual or postlingual (whether it occurred before or after age 3 years). For this dichotomy, we used the responses of deaf adults to the NHIS questions regarding the age range for hearing loss onset (n = 2,728; Table 1). People (n = 12) in the third age-at-onset category (hearing loss before their 19th birthday but unsure whether it occurred before or after age 3 years) were included in the postlingual group for the analyses.