The study found limited good-quality evidence, which makes it difficult to differentiate between the various methods for removing ear wax. Although the study was able to show that softeners have an effect in clearing earwax in their own right and as precursors to irrigation, it remains uncertain which specific softeners are superior. While caution should be taken in interpreting the results of the economic evaluation, the study shows that self-irrigation is likely to be more cost-effective than professional irrigation. The generalisability of the results, however, depends on how the clinical pathways assumed in the model are representative of typical clinical practice, as these are known to vary.
This findings are generally in line with previous systematic reviews in this area. However, this review differed because it assessed studies by setting, the intention for use of the softener, the populations, and the follow-up. It assessed all methods of treatment, including self-syringing; assessed all available preparation comparisons; and each study was assessed for methodological quality. The research was undertaken to fill an evidence gap identified as important by an expert advisory panel of the National Institute for Health Research Health Technology Assessment Programme, so that practitioners could be best informed about treatments for ear wax.
Given the large number of people attending primary care with earwax, it was surprising to find such limited good-quality evidence. There was little in the way of consistency among the included studies and many studies omitted basic data. This cannot be completely accounted for by the age of the publications, as many have been published since the advent of reporting standards for trials. While rigorous, consistent methods of critical appraisal and presentation were applied in this study, these factors made it difficult to summarise the results in a meaningful way.
Further research is required to improve the evidence base before policy and practice can be reliably informed. Ideally, a well-conducted randomised controlled trial and economic evaluation could provide an assessment of the different ways of providing the service (that is, practice nurse provision versus self-syringing) as well as the effectiveness of the different methods of removal. As part of this, it would be important to assess first the acceptability of different approaches, to ensure the most appropriate research structure.