Patients and other experts have worked together to identify the most important things to measure in research studies about treatments for single-sided deafness. Roulla Katiri, chief audiologist at the Mater Hospital in Dublin, and Lewis Williams, who developed single-sided deafness in 2018, explain how.
Take-home points
Lewis
It was just a normal Friday at work for me when I suddenly felt very dizzy and was struggling to hear in one ear. I was treated for labyrinthitis, an inner ear infection. But I was left with constant intrusive tinnitus and SSD. There was a wait to try a CROS hearing device, which reroutes sounds from the poor ear to the better hearing ear. I eventually got a cochlear implant in Germany, which I hoped would help me manage my tinnitus. 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…
Roulla
What is single-sided deafness?
Single-sided deafness (SSD), also called unilateral hearing loss, is defined as normal or near-normal hearing in one ear and a severe-to-profound hearing loss in the other ear.
What causes single-sided deafness?
Common causes of SSD in adulthood include acoustic neuroma (a type of benign tumour on the nerve leading from the inner ear to the brain), inner ear infections like labyrinthitis, and Ménière’s disease (a disorder of the inner ear). In some cases, the cause is not known, for example in sudden onset sensorineural hearing loss.
What is the impact of single-sided deafness?
Roulla
Difficulties in daily life as a result of SSD vary considerably from person to person. They may include difficulties in understanding speech in noisy environments and knowing which direction sounds are coming from. People’s psychological well-being and quality of life can also be affected. For example, reduced confidence and increased anxiety about taking part in work meetings and social situations.
Lewis
Everything that was effortless suddenly became challenging. Each day felt like extra time but with no final whistle in sight. There was no plaster cast or crutches to point at, so there was an assumption that I looked fine, so I must be fine. Listening and concentrating on conversations suddenly took up so much more energy, which eventually took its toll and I was exhausted.
By trait I am a social character and my friends would describe me as a bouncy ball, joking around reacting and having fun. This is where I had so much fun and spent such happy times adventuring with my buddies at festivals, out and about dancing and cycling. Just overnight my favourite amusements were taken from me, from meeting in our usual haunts and from the exhaustion I was feeling.
With the new controlling noise in my head, tinnitus, I was overcome with emotion, and this is when I started to drift away. The more I was exhausted the more I floated away. When I was out I would just zone off because I couldn’t keep up with the conversations. I might laugh at the wrong time, or I would go to the toilet for a break, and I would just realise I was alone, but the worst was when new people thought I was ignoring them and being rude.
Roulla
What can we do about single-sided deafness?
Devices like the Contralateral Routing of Signals (CROS) hearing aid, Bone Anchored Hearing Aids (BAHA) or middle ear implants are often trialled in the NHS. They can help with the hearing difficulties caused by SSD by rerouting sounds from the poor ear to the better-hearing ear. In some countries, like Germany, Belgium, France, North America and Australia, people may be offered a cochlear implant, which restores hearing on the poor side.
What is the problem?
Different researchers have been testing different effects (known as outcomesOutcomes are measures of health (for example quality of life, pain, blood sugar levels) that can be used to assess the effectiveness and safety of a treatment or other intervention (for example a drug, surgery, or exercise). In research, the outcomes considered most important are ‘primary outcomes’ and those considered less important are ‘secondary outcomes’.) of available treatments for SSD. 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. In our recent systematic review, we found that 96 studies conducted in the field of SSD used a total of 520 different measures to assess the various devices. This makes it difficult to compare results between studies, and work out which treatmentSomething done with the aim of improving health or relieving suffering. For example, medicines, surgery, psychological and physical therapies, diet and exercise changes. is best for a given individual.
How do we address the problem?
The CROSSSD study set out to address the difficulty of comparing results between SSD studies by developing a ‘core outcome set’ for SSD. We involved a large international group of healthcare users with experience in SSD treatments, as well as audiologists, ENT surgeons, clinical researchers, and industry representatives. They rated the importance of a list of outcomes by completing a series of surveys. Then a smaller group of experts had a web-based consensus meeting to discuss the important outcomes further.
Lewis took part in the CROSSSD studyAn investigation of a healthcare problem. There are different types of studies used to answer research questions, for example randomised controlled trials or observational studies.surveys and web-based consensus meeting. It was really important that we included people who are experts by experience of having SSD. It was vital that they helped us shape the study and decide what is most important to measure in research studies about SSD treatments.
Lewis
For me personally it is amazing that the CROSSSD study is happening. I am glad the information about SSD treatments will be there, easily found in one place, because when I was looking I couldn’t really find it. It was hard to collect this information. I think now, in the future, when it is easily found, so the doctors can hear and have the information there – that is an amazing thing.
It is great that the study was funded to be able to get all the different groups to sit down and talk about what was important, and looking at this subject in the bigger picture. For me it was so quick, from the event of going deaf and getting surgery, only five months, and being connected to the community was an emotional experience, finding out there where others out there.
Roulla
The core outcome set
We found agreement on three outcomes that should always be measured and reported in SSD treatment studies. These outcomes are: (1) Spatial orientation, (2) Group conversations in noisy social situations, and (3) Impact on social situations. Our short video provides a summary of the study outcomes.
The CROSSSD study team have created a ruler which can be used to measure the effect hearing devices can have on a person’s life like mine. It has been a fun experience taking part, and great to meet other people like myself. Most importantly, moving forward, there is a suitable way to easily review the information, and find the most appropriate solution, without getting lost in all the available the dataData is the information collected through research.. I was lucky to be able to find the correct solution for me, which restored normality to my life, and my friends remark on seeing that cheeky smile I have, which they had missed.
Lewis is a keen cyclist who likes to go to music festivals and is creative day-to-day. In November 2018 he had an ear infection following which he ended up with unilateral hearing loss and intrusive tinnitus. In May 2019 he travelled to Germany where he got assessed and underwent surgery to have a cochlear implant.
Funding
The main body of work for this project is funded by the National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre (BRC), funding reference number BRC-1215-20003.
Great work you two. So glad you’re smiling again Lewis
Thanks Paul!