Experts at the University of Nottingham have worked with people with single-sided deafness (SSD), to find out what effects from the condition matter to them the most, which in turn, will help towards developing more effective treatments for the condition.
The findings of the CROSSD study, which are being announced on World Hearing Day (3rd March), showed that spatial orientation (knowing which direction sounds are coming from), group conversations in noisy social situations, and the impact their condition has in social situations, were the three effects, also known as outcomes, that mattered to them the most.
SSD, also known as unilateral hearing loss, is when a person has normal hearing in one ear and severe to profound hearing loss in the other ear. Common causes in adulthood include acoustic neuroma (a type of benign tumour on the nerve leading from the inner ear to the brain), an inner ear viral infection, or Ménière's disease (a disorder of the inner ear). In some cases, the cause is not known.
There were times before my implant, I could have been surrounded by all my best friends in a pub, and I would feel so lonely, because I couldn't keep up. I didn't know what was happening. I wouldn't know where the conversation was going. I'd just be looking left and right. And it was quite sad…"
Devices like the Contralateral Routing of Signals (CROS) hearing aid, or Bone Anchored Hearing Aids (BAHA) such as the Oticon Medical processor or the Cochlear® devices are often trialled in the NHS. They can help with the hearing difficulties caused by SSD. In some countries a cochlear implant can be implanted.
Treatments have increased over years, but different studies into the condition have been inconsistent, measuring different effects or outcomes of a treatment, which makes it difficult to compare results – making it hard to work out the best treatment for individuals.
The CROSSD study has been looking at SSD and identifying which outcomes should be measured and reported on in SSD treatment studies consistently.
The study has been led by Audiologist and PhD student Roulla Katiri, supervised by Dr Derek Hoare, from the School of Medicine at the University of Nottingham. CROSSSD also involved an international group of healthcare users with experience in SSD treatments, audiologists, ENT surgeons, clinical researchers, and industry representatives.
As part of the study, 308 people from 29 countries completed surveys to share what they thought was important to measure. From this, a shortlist of 17 outcomes were discussed in depth with international key stakeholders during online meetings. Three core outcomes were recommended to be measured as a minimum in all future SSD treatment studies. Work is now underway to decide how we can measure these core outcomes.
Roulla said: "In our recent review, we found that 96 studies conducted in the field of SSD, used a total of 520 different measures to assess the various devices. Examples of the many outcomes that have been used in SSD studies include how well an individual can hear speech above noise, how easily they can locate a sound, or how a device affects their quality of life. This makes it difficult to compare results between studies, and work out which treatment is best for a given individual. "Now we have our three core outcomes, we can use them in all future studies to more easily compare results and accelerate our understanding of what treatments are ideal."
Carly , one of the CROSSSD study participants, reflects on her experience in taking part in the Delphi surveys and the web-based consensus meeting: "I really enjoyed having the opportunity to connect with other people with SSD and professionals with a keen interest in the development of SSD interventions. Bringing together people from a variety of specialisms encouraged an active and productive discussion, and the experience was educational for all. It was an honour to represent the healthcare user and to be involved in the making of important decisions that will shape the future of SSD research."
You can watch a video on the study here.
