Discussion

This study highlights a wide range of ENT-specific applications that are available. A number of studies on smartphone usage amongst medical trainees have been published,^{Reference Dimond, Bullock, Lovatt and Stacey6–Reference Hardyman, Bullock, Brown, Carter-Ingram and Stacey8} in addition to specialty specific (maxillo-facial,^{Reference Carey, Payne, Ahmed and Goodson9} urology^{Reference Nason, Burke, Aslam, Kelly, Akram and Giri10} and plastic surgery^{Reference Reusche, Buchanan, Kozlow and Vercler11}) reviews. In comparison with a study conducted in the USA in 2015 that detailed the availability of ENT-specific mobile applications,^{Reference Wong and Fung12} our study suggests both an increasing number and diversity of ENT-specific applications. As pre-empted in the review by Wong and Fung,^{Reference Wong and Fung12} evolving technology has resulted in an increasing number of applications allowing smartphones to be directly used in clinical assessment.

The ability to use smartphones as a tool for clinical assessment has huge potential for telemedicine, as discussed in a study by Swanepoel and Clark.^{Reference Swanepoel and Clark13} The ability to accurately measure hearing with minimal equipment, using applications such as the e.audiologia Hearing Test, provides the opportunity to deliver hearing healthcare to communities where previously it would have been unfeasible. Additionally, the ability to capture otoscope views with a smartphone and to share them remotely facilitates improved ENT care for those in isolated communities. Studies have shown the benefits of using telemedicine to aid triage in the community, providing an effective way to manage referral to tertiary ENT care.^{Reference Gupta, Chawla, Gupta, Dhawan and Janaki14} Smartphone applications that convert the phone into an otoscope are beneficial to such community triage schemes; the Cupris otoscope was shown to be a low-cost tool to screen for ear disease in remote locations in low- and middle-income countries.^{Reference Mandavia, Lapa, Smith and Bhutta4}

Remote image sharing would also be advantageous in a National Health Service setting. The secure sharing of images via smartphones is particularly pertinent to ENT departments, where the senior on call is often not resident. The ability to share otoscopy images would facilitate juniors seeking senior advice, and the option to store images would allow clinicians to monitor a patient's progress chronologically without having to rely on documentation or memory.

The quality of advice that can be given remotely clearly depends on the quality of the images, and this is something that can be expected to improve as the applications become more widely used and smartphone technology progresses. Although small scale, one study has shown that an accurate diagnosis can be obtained from still images taken using a mobile phone otoscope. However, some conditions, such as middle-ear effusion, proved more difficult to visualise and correctly diagnose.^{Reference Moberly, Zhang, Yu, Gurcan, Senaras and Teknos15} When comparing smartphone otoscopes to traditional otoscopes, clinicians preferred the phone attachment. There are clinical implications when switching to a smartphone otoscope after examining with a standard otoscope because clinicians often changed their diagnosis.^{Reference Richards, Gaylor and Pilgrim16} Patient feedback was positive during a study comparing traditional microscopy to the new phone-based otoscope; patients appreciated the opportunity to visualise the pathology and felt it gave them a better understanding of their condition. When clinicians diagnosed from the smartphone images, the positive predictive value was 97 per cent.^{Reference Moshtaghi, Sahyouni, Haidar, Huang, Moshtaghi and Ghavami17}

Although the use of smartphones during consultations can be expected to vary according to individual preference, the studies investigating the use of smartphone otoscopy noted a predominantly positive response from patients. There are a number of applications available to facilitate the doctor-patient encounter, such as Draw MD, which allows the smartphone to be used to provide patients with visual information during a consultation. A study has shown that 40–80 per cent of information conveyed in a consultation is immediately forgotten, and of the information that is retained, up to 50 per cent is remembered incorrectly.^{Reference Kessels18} The use of illustrations when explaining to a patient has long been promoted and acknowledged to improve patient compliance.^{Reference Delp and Jones19} When illustrations are used in combination with oral communication, their effectiveness is further increased.^{Reference Katz, Kripalani and Weiss20} Draw MD offers a modern and accessible way to provide the visual information patients require in order for them to understand and retain information accurately.

Hearing tests represent a significant proportion of the available applications, although one study has noted that very few have been validated in peer review studies.^{Reference Bright and Pallawela21} Other examples of applications available for use in clinical assessment include an application to objectively measure the Unterberger and Romberg test,^{Reference Whittaker, Mathew, Kanani and Kanegaonkar22,Reference Yvon, Najuko-Mafemera and Kanegaonkar23} and there has also been a preliminary study completed on a smartphone application to measure bone conduction thresholds.^{Reference Dewyer, Jiradejvong, Lee, Kemmer, Henderson Sabes and Limb24} Smartphone otoscope technology has become more established, and there are numerous studies comparing their use to traditional otoscopy as previously discussed. The use of smartphones during nasal endoscopy, using applications such as Save My Scope, represents a relatively new area of development. As such, fewer research papers exist, but initial research has shown encouraging results.^{Reference Quimby, Kohlert, Caulley and Bromwich25} The number of novel applications for use at the bedside will inevitably grow as technology progresses.

Data protection is an important consideration when using smartphone applications, and concerns regarding security could be a major deterrent for their usage. This is particularly relevant if the applications are used on personal devices or used to communicate patient-identifiable data or images. A lack of a regulatory framework for healthcare applications can leave the degree of security to the discretion of individual developers. One article assessing the usage of mobile phone applications in the management of bipolar disorder recommended that users exercise caution when using the applications becasuse most lacked privacy policies.^{Reference Nicholas, Larsen, Proudfoot and Christensen26} Another article noted that even if the application did have a privacy policy they may be difficult to access and not specific to the application itself.^{Reference Sunyaev, Dehling, Taylor and Mandl27} Nevertheless, there are an increasing number of recommendations regarding security and data protection measures for the applications,^{Reference Morera, de la Torre Díez, Garcia-Zapirain, López-Coronado and Arambarri28} including tools developed to help application designers improve the security of their software.^{Reference Parker, Karliychuk, Gillies, Mintzes, Raven and Grundy29} Although it remains the clinician's responsibility to be confident that the applications they use are secure, it can be expected that the security requirements will become more stringent as this field continues to grow.

In addition to security concerns, it also remains difficult to assess the quality of available applications. This review is limited in the same way as users trying to search for applications for clinical use. The mobile application stores’ search functions are limited and do not allow for the use of filters. Searches return a large number of results without the ability to identify the applications intended for professional use. Specialist search terms return very few results, while more generic terms return large numbers of applications, which users have to sift through to find those that may be clinically relevant. Without downloading the application, which in some cases requires payment, this judgement can only be made on very limited information provided in the description of the application, and the quality and security of the application can be hard to determine.

As a consequence, further research is required to ascertain the quality of an application; it is often possible to establish the qualifications of the developers via the application's description or the developer's website. Of the eight applications reviewed, over half had a doctor or allied health professional involved in their development. The majority also had published research relating to the application; however, this was often a single article, in some instances authored by the application's developer. Finding an objective evidence base for smartphone applications is arduous, and the information is often lacking. Although the number of applications is growing, establishing their security and validity still represents a significant challenge.