A comparison of the clinical effectiveness of pretreatment olive oil administered as drops versus spray prior to earwax removal by microsuction in adults: a protocol for a cluster randomised control trial.

Background: Excessive earwax causes unwanted symptoms such as hearing loss, tinnitus, discomfort and changes in the quality of one’s own voice. The NHS Audiology Wax Removal Service in North Wales recommends the use of olive oil as a pretreatment wax softener administered as either drops or spray prior to microsuction. For one in four patients microsuction is unsuccessful at the first attempt. Anecdotal evidence suggests that the administration of olive oil as a spray is a more effective pretreatment. This trial aims to explore whether administering olive oil pretreatment softener is more effective when administered as drops or spray. Methods: This two-arm cluster randomised control trial will be conducted within the existing NHS Audiology wax removal service in North Wales from January to July 2025. This pragmatic trial involves 26 NHS GP practices (clusters) and compares the administration methods of olive oil pretreatment via drops and spray. A sample size of 1,742 participants (67 in each of the 26 practices) was calculated as sufficient to determine a clinically significant difference. Presumed consent is used for all eligible patients seen within the wax removal service. Patients will be advised to source and self-administer three drops or sprays of olive oil for seven days before attending a wax removal microsuction appointment with an audiology practitioner where routine anonymized data will be collected. The primary outcome is whether wax removal is successful, as assessed via visual examination. The secondary outcomes include: improvements in self-reported symptoms, the amount of residual wax following microsuction and the number of adverse events. Statistical analyses will be conducted with an intention-to-treat design to compare outcomes between the groups. Discussion: . This RCT aims to investigate whether administering olive oil as a pretreatment wax softener via drops or spray affects the outcome of wax removal. The outcome of this trial will inform future recommendations to patients and improve service effectiveness and efficiency by reducing the need for repeat visits. The results will be shared nationally and used to inform national guidance on wax removal. Trial registration: ISRCTN, ISRCTN28211073. Registered 23 December 2024, https://www.isrctn.com/ISRCTN28211073?q=earwax&filters=&sort=&offset=1&totalResults=3&page=1&pageSize=10