Can anonymised patient records be used to assess the extent of preventable hearing loss from prescription medication in the UK?

Background The World Health Organisation (WHO) estimates that around 50 percent of all new cases of hearing loss each year could be prevented. Many of these are caused by exposure to loud noise, either at work or recreationally. However, a substantial number are linked to disease, or more commonly, the treatment of disease with medicines that can damage hearing as a side effect. It is estimated that there are around 34 million new cases of disease-related hearing loss worldwide each year, with certain medications accounting for around 32.4 million of these. These figures are based on data taken from published studies. However, relevant data is often missing for certain countries; their number of new cases is then estimated based on figures from other countries in their region. This means it is difficult to assess the real incidence of disease-related hearing loss for any given country. In the UK, the incidence of drug-induced hearing loss is not well documented. The NHS Open Data Portal contains data on the types and amounts of medication prescribed in the UK, but these data are reported as the number of prescriptions and are not linked to a particular patient or any side effects reported, making it difficult to link medication usage to hearing loss. The Secure Anonymised Information Linkage Databank (SAIL Databank) is a repository of billions of health care and administrative records from 30 years of routinely collected data about the population of Wales. This anonymised data contains GP records for the entire population of Wales, including prescribed medications and health issues such as hearing loss. Aim The aim of this pilot project is to see if the data held within the SAIL Databank can be used to understand the extent to which drug-induced hearing loss impacts the population of the UK. In addition to this, the researchers will investigate whether the SAIL Databank can be used to identify medications which can damage hearing that are not currently considered to cause hearing loss. Anonymised SAIL data will be sorted for relevant information such as records of people with hearing loss and people who have taken medication known to damage hearing. These records will be compared to identify if people have developed hearing loss related to the medication they have taken. In addition, the team will compare records of people with symptoms that resemble drug‑induced hearing loss to see whether any have been taking medications not currently described as harmful to hearing. Benefit If successful, the researchers plan to scale up this work to include people with drug-induced tinnitus and balance disorders. They will also test any medication they identify as being potentially harmful to hearing in the lab to confirm if they do indeed cause hearing loss. These findings could be used to inform policy around how these drugs are prescribed and provide data on the types of medication that result in hearing loss to scientists developing new drugs.