Basic Services for the Elderly Deafblind: Surveys and Statistics.

Ole E Mortensen is Information Manager at the Information Center for Acquired Deafblindness in Copenhagen. Before that he was a teacher at the Department of Communication, Roskilde University. He presented the following paper on deafblind statistics at the Poitiers Conference.

This study will focus on the elderly deafblind. It will examine those who have become deafblind due to age related vision and hearing impairments. Although this is by far the biggest group within the deafblind ppulation, it is a group that has been largely ignored in most countries until now. This has resulted in many people not receiving the help, support and assistance that they need.

In order to offer services to the elderly deafblind we need to know things, such as:

Elderly people who acquire deafblindness in old age are fairly invisible in society. They live in their own homes or in institutions, where their sensory loss is not noticed, or just considered an inevitable part of growing old that must be accepted.

In some countries in Europe there is a growing awareness of this group as a result of surveys to establish the size and characteristics of their problems. Three of these were carried out in Holland, Denmark and the UK. Although the reports differ in the way they present their findings, distinguish between age groups, and describe the cause of deafblindness, I have identified some key points and findings. The surveys all used the same functional definition of deafblindness.

There are several differences in the methods used in the surveys and it is interesting to notice that despite these differences, the results they produced were in many ways very similar.

It should be noted that none of the studies and surveys claim to have found exact and accurate numbers. There is still a lot of estimation and even guesswork involved in many.


Until the 1990s estimates of the number of elderly deafblind were based on the "Breaking Through" report of 1988. This estimated the number of deafblind people in the UK to be around 25/100,000. Sense, the National Deafblind and Rubella Association, has been involved in conducting the latest survey in the UK.

The various methods used to assess each region in the UK employed:

These survey produced an average number of 21,000 deafblind people of all age groups in the UK (approx. 40/100,000). Survey findings ranged from 30/100,000 to 58/100,000.

According to estimates made by Sense, approximately 14,000 (60%) of these were elderly, mostly deafblind due to age related impairments.


The known number of deafblind people in Holland was 300 (2/100,000) until the 1990s, when two large surveys were conducted. One counted all deafblind people in the country (1991), and the other focused on the elderly deafblind living in rest homes and nursing homes (1993). Both were carried out by Stichting Doof-Blinden.

In 1991 the survey "Deafblindness in the Netherlands" researched all GP's and nursing homes in the country for the numbers of deafblind individuals in their care. 6,700 letters were sent out, to which there was a response rate of around 80%. The registers of the mentally handicapped were also examined. From the responses it was estimated that there was a deafblind population of around 2,250 (a prevalence of 15/100,000) with approximately 1,600 elderly deafblind.

The second survey, "Old age deafblindness" was sent to 1,850 resting and nursing homes for their reports of deafblind inhabitants. Elderly people who live in their own homes, although a large proportion, were not counted, since the purpose of the survey ws to look at the situation of deafblind elderly people in institutions.

Approximately 2,700 elderly deafblind people were found, which enabled an estimate of 3,000-4,000 deafblind people in a population of 15 million to be made (a prevalence of 20/100,000-27/100,000).


Denmark has 16 counties. A study was made of one of them, Aarhus, which, with a population of 600,000 contained around 11% of the Danish population. The survey was conducted by the Information Center for Acquired Deafblindness. Personal contact was made with the field workers before they were asked to report every person they knew of with a combination of vision and hearing impairments. This was followed up with an interview to determine whether the reported persons fell inside their working definition of acquired deafblindness.

118 people were identified as having acquired deafblindness. This enabled an estimate for the number of people with acquired deafblindness in Denmark to be made at 1,100 (a prevalence of 22/100,000). If the figure of 150 congenitally deafblind is added, there is a prevalence of 25/100,000 deafblind people in the population.

What do the surveys show?

Many things. They give us a more authentic image of the groupings within the deafblind population. The percentage of elderly deafblind people within the deafblind population has been estimated at:

The elderly population was determined as people over 65 years.

UK - In every 100,000 persons over 65 it is estimated that 255 of them are deafblind because of old age! The Royal National Institute for the Blind have carred out a survey which shows a very high prevalence of hearing probems in visually impaired elderly people.

Holland - There are about 2 million elderly people in Holland. Of that population, around 135 in every 100,000 are deafblind and living in nursing and rest homes. The numbers from Holland on elderly deafblind are probably an under-estimate, since many elderly people live in their own homes and were not counted.

Denmark - When looking at the causes of deafblindness we find that 82% of the people with acquired deafblindness in Denmark are deafblind because of old age. In Denmark 710,000 people are over 67 years, 900 of whom are deafblind because of old age, which gives a prevalence in the elderly population of 127/100,000.

Survey Methods

The following research methods were used, and problems encountered during the surveys:

Studying registers of the hearing impaired, visually impaired and mentally handicapped: This requires the existence of, and access to, registers.
Postal questionnaires to medical and care staff: Respondents must be willing and able to respond, understand the demands of the survey and able to recognise when a person is deafblind.

Questionnaires after initial contact: This generally produces a better outcome, since there is an opportunity to clarify the questionnaire and motivate people to respond.
Qualitative methods: This involves meeting the people who might be in contact with the deafblind.

Doubts are often expressed over the validity of survey findings due to inconsistent definitions used by the respondents. In many surves the feeling is expressed that the figures are probably an under-representation of the true number.

In the surveys examined, functional definitions were used, such as the following:

"A person is deafblind when she/he has a severe degree of combined visual and auditory impairment. Some deafblind people are totally deaf and blind, while others have residual hearing and residual sight. The severity of the combined visual and auditory impairments means that deafblind people cannot automatically utilise services for people with visual impairments or with hearing impairments... Deafblindness must therefore be regarded as a separate disability which requires special methods for coping with the functions of everyday life." (Nordic Survey)

A functional definition depends on a subjective assessment. How do you define "severe" so that everyone will have the same understanding of the word? This may be overcome by using a medical definition. Denmark applies this for assessing blindness; diagnosing blindness when vision is 6/60 or less. When using a medical definition it is much clearer who is included in the group and who is excluded.

The validity of a survey depends on respondents sharing a definition of what is being examined. The surveys mentioned here raise this question when they reveal discrepancies between areas otherwise inexplicable in demographic terms.

In addition to surveys of the number of deafblind people, there have been estimates of the number of people with a combined visual and hearing impairment. In 1991 the Royal National Institute for the Deaf in the UK estimated that there were 50,000 people with some degree of both visual and hearing impairment, (approximately 431/100,000). They also discovered that may be as many as 45% of people aged over 75 with visually impairments who also have difficulties with hearing. The Danish survey revealed similar findings, indicating a prevalence of combined visual and hearing impairment in the elderly population of 346/100,000.

Although I have discussed the findings of a range of surveys which used different methods and were conducted in different countries, it is clear that deafblindness is experienced by a substantial proportion of elderly people. While the exact prevalence can be argued, it should be agreed that we must now find ways of assisting this significant group of people who have acquired deafblindness.

Ole E Mortensen

Ole can be contacted at the Institutionen for Dove, Generatorve, ZA, DK-2730 Herlev, Denmark.

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