Beginning in 2010, the Quality of Life/Functioning and Disability supplement was fielded to sample adults, to develop and test improved measures of functioning. According to the 2010 NHIS Survey Description, this element of the survey was "part of a partnership with the Washington Group on Disability Statistics (WG) and the Budapest Initiative on the Measurement of Health State (BI)." Other disability questions developed by the WG and BI groups were included in the NHIS beginning in 2008. More information on the WG and BI efforts are available on the Internet.

Sample adults who answered no difficulty, some difficulty, or a lot of difficulty to HRPROBAMT in the Quality of Life supplement were asked a number of follow-up questions. The variables based on these other follow-up questions include:

• HRAUSESQOL: Uses hearing aid (quality of life supplement)

• HRAFREQ: Frequency wearing hearing aid, past 12 months

• HRDIFCONV1QR: How difficult to hear conversation with 1 person in quiet room

• HRDIFCONV1NR: How difficult to hear conversations with 1 person in noisy room

In addition to covering hearing, the supplement asked about difficulty with vision, mobility, self-care, learning, cognition, communication, fatigue, pain, and emotions (anxiety and depression). Persons acknowledging difficulty in these areas were asked follow-up questions regarding the degree of difficulty, use of assistive devices, and functioning with assistance.

In 1984 the supplement on aging was asked of all nondeleted persons in the family 65 years or older and of a sample of nondeleted persons in the family 55 through 64 years of age. The Field Representative's Manual for 1984 defines a hearing aid as "a compact amplifier worn to aid one's hearing. Do not include devices not worn by the person, such as phone amplifiers, etc.".

Other variables related to hearing available in the 1984 survey include:

"Hears most things people say, with hearing aid" (HRMOSTSAID), and (HRFEWORDS) whether the respondent hears only few words (with hearing aid).

In 2019, functioning and disability measures included on the NHIS questionnaire were modified to align with validated, internationally-comparable disability measures developed by the Washington Group on Disability Statistics (WG). For more information about the WG initiative, other WG functioning and disability measures included on the NHIS questionnaire, and guidance for researchers about how to use the WG measures in analyses, please see our user note on the Washington Group Disability Measures.