Interventions for hearing and vision impairment to improve outcomes for people with dementia: a scoping review.

Abstract

Electronic databases were searched using key terms dementia, hearing impairment, vision impairment, intervention, and management. Database searches were supplemented by hand searching bibliographies of papers and via consultation with a network of health professional experts. Studies were eligible for inclusion if they included adults aged over 50 with dementia with adult-onset hearing or vision impairment who had received a hearing or vision intervention in relation to cognitive function, rate of decline, psychiatric symptoms, hearing/vision-related disability, quality of life, and/or caregiver burden outcomes. A range of study designs were included. Results were summarized descriptively according to level of evidence and effect sizes calculated where possible. Risk of bias was assessed using Downs and Black's (1998) checklist. The development of the intervention was summarized according to the CReDECI2 scheme. PROSPERO review registration number 2016:CRD42016039737. Twelve papers describing hearing interventions and five papers describing vision interventions were included. Most were of low to moderate quality. One high quality randomized controlled trial of a hearing aid intervention was identified. Hearing interventions included provision of hearing aids, assistive listening devices, communication strategies, hearing aid trouble shooting, and cochlear implantation. Vision interventions included prism lenses, rehabilitation training, and cataract surgery. There was no consistent evidence for the positive impact of hearing/vision interventions on cognitive function, rate of cognitive decline, quality of life, or caregiver burden. Sensory interventions may promote better outcomes, but there is a need for properly powered, controlled trials of hearing and vision interventions on outcomes relevant to people living with dementia.