As a clinician, it is our responsibility to understand the limitations and capabilities of the tools that we use in our process of gathering information from and about a patient to further the diagnostic and management process. When we use a stethoscope to listen to heart sounds, we understand that it is more important what the tool is keeping you from hearing than what you are hearing. So even though one can hear the primary “lub-dub” of the heart with a toy stethoscope, we use a higher quality tool so we can hear the murmurs and faint sounds that allow us to determine the presence or absence of pathology. In the same manner, videoconferencing and other communication tools have their limitations and technical issues that a clinician needs to be aware of – which is what we’ll be focusing on.
When clinically assessing telehealth related technologies, it may be helpful to keep in mind the following: When a clinical provider is presented a patient whether in person, by video, phone, or in a textual description of the condition, we inherently consider the information that we have been able to collect and the differential diagnosis of possible conditions. The information collected allows a provider to eliminate various items from the differential list while others remain until enough information is acquired to sufficiently remove them. In the office setting, this often means that after we’ve exhausted the amount of information that we can obtain, we often need to send the patient for additional testing such as labs, imaging, or various procedures. In the setting where the interaction is limited by video, audio, or a textual presentation, it simply means that we are unable to remove some items off the differential when compared to those we may have comfortably removed when seeing the patient in person, or a different setting.
In this mindset, the goal to assess the telehealth technology from a clinical perspective is to identify what information this technology allows one to collect, and more importantly, what are the limitations of that information, and how will that affect the differential diagnosis. An easy example using some extremes is to consider the resolution of a photograph or video. The lower the resolution, the less detail an image can portray. At a very low resolution, a provider may easily be able to determine gross findings like the patient is missing their leg below the knee and easily support a request for a referral to a prosthetic lab but, at that same resolution, have difficulty in determining the characteristics of a rash enough to justify a request to prescribe a medication. In such a situation, the ability to work through a differential may or may not be impacted by the resolution of the image depending on the presentation of the clinical situation.
As technology and devices dedicated to remote assessment improve, the clinical provider may also consider including this technology for the in-person exam and office setting. This is no different than what clinicians do when showing a patient their x-ray and explaining the findings. With telehealth technology, one can easily show the ear drum, a red throat, or retinal finding, all of which in the past, haven’t been easy to share with the patient.
Clinical Assessment Considerations
Historically, video technology used in healthcare was referenced as “video conferencing” much like it is used in the business world to support a meeting or conference where numerous individuals participate. This makes sense because for all practical purposes, it was often the exact same equipment. While there are situations in healthcare where more than two individuals are participating, most of the conversations in healthcare with a patient are between two people – the patient and their provider. As some practices may only be interested in solutions that allow a two-person interaction, or in a few cases, the addition of a third or fourth party for interpreter services or to include a remote family member, the term video chat is included as are technologies that are primarily focused on these types of communications between only a few participants.
Regardless of whether the equipment is referred to as video conferencing, video chat, or some other name, there are a few variables that will be important to be aware of for a clinician who is interested in working through a diagnostic process over video.
Resolution and size of screen
This issue really depends on the clinical situation that you are engaged in. In the ATA published guidelines, for tele-mental health use, the suggestion states that “transmission speed shall be the minimum necessary to allow the smooth and natural communication pace necessary for clinical encounters” – which is quite subjective and really depends on what the clinician wants to accomplish. The ATA’s guidelines for tele-dermatology state that the technology shall have a minimum of 4CIF (704×480) pixels or higher. As one can see, the barrier is set quite low and it should be noted that high-quality care has been provided for decades at these resolutions.
With the rapid adoption of cell phones, the situation has been created where there are very small screens that have very high resolution. Typically, large hospital systems purchase monitors in bulk and are usually 17” monitors with a typical resolution of 1280 x 1024. These days it is much more confusing as the mobile device you are carrying in your pocket may have a higher resolution than the monitor on your desk. At the end of the day, the final decision rests with the clinician to determine if the technology is sufficient for the presented clinical case
Color accuracy
Color is one of those things we don’t usually think about too much but for clinical services like dermatology, infectious disease, wound care and others, color can significantly affect the diagnosis or impact the perception of the severity of the condition. Most of us have probably not calibrated our monitors for color accuracy and few possess the equipment to do so. Most current phones are quite good at representing accurate colors, However, older phones such as those released around 2012 and earlier were significantly deficient in their ability to display accurate colors, due to the limitations of the screens and the technology at the time.
One solution is to make sure you have a way to calibrate the colors from images and video. The easiest way is to ask that the person taking the picture to place an object with known colors in the picture. There are several software products on the market that provide color correction solutions.
Having the patients photographed or presented on video in an appropriate light is a critical and inexpensive first step for capturing accurate and consistent color. Most light fixtures can have their bulbs replaced with a “sunlight” or “true color” bulb, which refers to a bulb with a light that is in the 5500 Kelvin temperature range.
Frame rate
Frame rate shouldn’t be much of a problem unless you are trying to do video on a lower bandwidth application. Of course, if your clinical situation is assessing a movement disorder, then frame rate may be a significant factor. If your set up has access to a bandwidth of 384 Kbps and you are using a typical H.264 or VP9 codec, then to experience 30 frames per second you are probably limited to a resolution of CIF. The math is straight forward as an HD 720p image (1280×720 pixels) carries 24 bits of color/intensity data that refreshes at 30 frames per second. These settings would generate about 664 Mbps of data. The codec compresses this down to about 2-3 Mbps so it can be sent over the network. Higher resolutions quickly increase the amount of data being sent for each frame. Again, the clinician will need to make the determination whether the frame rate is impeding their ability to remove something from the differential diagnosis or not and plan .
Audio clarity
Audio is probably the most important factor and is often under invested in, or over looked altogether. Audio quality has a significant affect in the perception of the quality of the experience and impacts the users experience much more than video. It is pretty obvious that both the clinical provider and the patient should be able to clearly understand each other when talking; this is often harder to accomplish in a video exam environment. Most microphones for traditional room video conferencing capture a lot of background noise so one option is to consider a lapel microphone or a desktop directional microphone if you are going to be providing services from a specific location or .
Clinical exam rooms are rather standard in design and made for keeping things clean and free of germs. This means lots of hard surfaces, which sound bounces off quite well. This can lead to echoing or feedback at times. If possible, having sound absorbing materials on the wall or in the corners of the room can help to reduce the feedback and echo issues.
Asynchronous video
If the clinic schedule or workflow doesn’t allow for 2-way video to be used, asynchronous video has been shown to be an effective way to gather information. Dr. Peter Yellowlees, a psychiatrist at UC-Davis in California, uses asynchronous video in his practice. In this setting, the history and physical exam obtained at the remote site is recorded and sent to Dr. Yellowlees. At his discretion he then evaluates the content and replies with his impression and any issues that need to be clarified or further explored. Much like the asynchronous experience in chat or messaging applications that are quite common on mobile devices, this approach to patient care can overcome numerous obstacles when a live 2-way communication is not possible for technical or coordination .
While effective, this approach is considered novel and has not be adopted by many of the health insurance companies or Medicare for compensation, so adoption of asynchronous service is most attractive for capitated markets or those services funded outside of the insurance market.