Validation of Cognitive Screenings for the Hearing Impaired

Overview

There are currently no cognitive tests that have been validated as screening tools for people with dementia and comorbid hearing loss. This is particularly important given the high prevalence of hearing impairment in older adults presenting to memory services and the risk of misdiagnosis of dementia in this population as outlined above. Cognitive tests validated in hearing impaired populations will also be important as outcome tools for interventional research aiming to find out if treating hearing loss may reduce dementia risk in the longer term.

Hearing loss is very prevalent in older population. This leads to further problems such as communication problem, isolation from the community and depression. Moreover, hearing impairment may potentially affect the patients' cognitive function as demonstrated in the above mentioned published papers. Communication problems that arise from a hearing loss alone can also interfere with administration of cognitive test battery, as a previous study showed that re-administered of MMSE test with assistive listening device can immediately improve the test score among elderly (1). Therefore, special adaptation of the cognitive test battery to address the needs of hearing impaired older adult is necessary. This is to ensure that the test result reflects the exact cognitive state of the older adult with hearing impairment, not effected by hearing loss. Moreover, appropriate cut-off point scores for hearing impaired population should be identified for these new cognitive screening tools. This is to ensure appropriate referral for further diagnosis and prompt management for cognitive impairment/dementia among older adults with hearing loss. In addition, since hearing loss can potentially lead to deterioration in patients' cognitive function over time (2). Follow up assessments of cognitive function among older adults with hearing impairment can determine the rate of deterioration in retrospective trial(2). This prospective trial follow up of cognitive function among hearing loss participants may uncover additional risk factors associated with the deterioration. Better understanding of these risk factors can potentially lead to further intervention in order to delay decline in patients' cognitive function.