Discussion
This is the first study to directly compare performance of different methods for diagnosis of external and middle ear disorders. We report variable results. Prediction model diagnosis using automated history performed poorly, but an absence of otorrhoea (perhaps unsurprisingly) was found to reliably exclude CSOM. This implies that individuals who deny a history of ear discharge could confidently be excluded in programs screening for CSOM.
Whereas both nurse-led and remote expert diagnosis showed high specificity, they had low sensitivity. The reasons for poor sensitivity can only be surmised, but could include poor performance of the questionnaire, poor quality video capture on otoscopy, insufficient video resolution, low experience or confidence of the assessor, or diagnostic uncertainty or disagreement. Poor image capture and diagnostic incongruity has been reported in other studies.7
We recognise our study as a preliminary exploration of methods for screening or diagnosis of middle or external ear disease (where on-site specialist assessment is unavailable). Future work could look to evaluate if and how validity of these approaches may be improved, including through improving the quality or platform for image capture to assist remote diagnosis; targeted training of non-experts to develop diagnostic skills; or providing additional or enhanced information to facilitate prediction model diagnosis (in particular the addition of automated interpretation of otoscopic images).10