Nowadays, home use medical devices are now widely used in patients’ homes, enabling them to treat and care for themselves. The use of haemodialysis is increasing with rising incidences of kidney disease. There is a common theme in kidney disease treatment research that home haemodialysis devices (HHDDs) are the current treatment of choice for End-stage Kidney Disease (ESKD), and will increasingly be so in the future to meet the growing demands for renal services.
HHDDs are different from other home use medical devices in several ways. Firstly, compared to other types of home-use medical devices, programmable medical devices are more difficult to use at home. They are interactive and require patients to program settings when they are used, which places a higher demand on patients. And secondly, programmable devices are more difficult to design to be patient-friendly, due to their complexity. The main programmable home use medical devices being used in the UK were identified as being HHDDs and ambulatory infusion pumps. HHDDs themselves are used to filter a patient's blood to remove excess water and waste products when the kidneys are damaged, dysfunctional, or missing. Users of HHDDs typically need to program the dialysis duration and the volume of fluid to be removed from the patient. It includes other interactive features such as alarms, which prompt the user to react to certain events. Therefore, this is a nascent field and there will clearly be some unique issues associated with patients using HHDDs.
1. Non-user-friendly design
Although patients have relative autonomy from hospitals when using HHDDs, none of this equipment is perceived as truly user-friendly. In particular, the current design of HHDDs is not suited for the home and does not meet the diverse and changing needs of different patients’ age groups or conditions. There are complications which occur during the procedures. Complications typically arise in complex procedures “both related to the patient, e.g. self-cannulation, and related to the use of the programme, e.g. programming the treatment on the machine and setting up the circuit” (Rajkomar, 2014). They also occur during procedure operations in pre-use and post-use, such as checking water quality and disinfecting drainage lines. What is more, during the use procedures, interface issues are the main “complications”. Interface in this context can be defined as the components or features of the HHDD that allow interaction or communication with the patient. HHDDs are cognitively complex, in some cases, as “even though the machine coordinates resources and attempts to tell the patient what the problem is, the machine’s message is not always understandable to the patient or does not adequately guide the patient on the course of action” (Rajkomar, 2014). In other words, current interfaces provide a poor indication of how to operate HHDDs. Another example of poor interface design is when re-lining the circuit during the wash-back phase, HHDDs cannot tell whether the patient connected the ends correctly or not. If patients connect it incorrectly, they may suffer a fatality.
A number of people dialysing at home were asked to put forward their recommendations to improve the interface offered by their current HHDDs (Farrington et al., 2011). Suggestions for an improved interface included: reduced display complexity, and an increased capacity for interaction with users (Farrington et al., 2011). Due to the procedures of HHDDs being complicated for patients, it is important that interface design ensures that it can use safely and effectively. The poor interface design of equipment can not only cause patients harm but can also impose significant constraints on patients and carers: for example, by limiting their activities and mobility.
2. Ignoring the of disabilities
Patients may have various disabilities (e.g. physical, perceptual, cognitive disabilities), and impairments (e.g. limited vision, impaired tactility and hearing loss), they may find it difficult to use HHDDs. This requires HHDDs to be designed to engage patients, especially older patients who have limited capabilities. However, in fact, the current interface design of HHDDs is far from meeting the requirements needed in a real environment.
One example of this is the use of HHDDs. Some patients have trouble reaching their devices comfortably from their position on beds or chairs. Also, patients find the physical buttons and clamps of their machines hard to press. An example from the FDA explains how an HHDD had a lack of consideration for a patient’s limited physical capabilities. “A patient doing home nocturnal dialysis was found by her husband, unresponsive. She was disconnected from the dialysis machine, and her tubing was in a closed circuit filled with saline. There was a syringe attached to one of her lines, but the other line was open, and the patient had lost a significant amount of blood. It appeared that she had been unable to clamp her catheter by herself. The patient died due to blood loss” (FDA, 2010). Likewise, even if patients have prior experience using devices, they may still have difficulty in doing fiddly tasks such as manipulating syringes and supplies, e.g., some patients may accidentally inject air into their dialysis circuit while injecting a drug into it with a syringe. Additionally, older patients who have limited ability, as with cognitive issues, cannot use devices like HHDDs safely and effectively. They may forget one, or more than one steps of the operation when using the device, for example forgetting to use the anticoagulant, which prevents them from finishing all the steps correctly.
Furthermore, in some cases, during the procedures, some older patients rely on visual and auditory elements of their physical environment to help them perform certain steps or deal with some situations. An example of a physical element is the visibility of the blood’s colour. From the patient interviews in Rajkomar’s (2014) dissertation: “Once the unusual blackish colour of the blood indicated to Gina that something was wrong, and she found out later that the anticoagulant that she had used was from a defective batch. This suggests that, though it could possibly be better for the patient not to see their blood during treatment, e.g. by having opaque lines, the visibility of the blood can let the patient know of certain problems” (Rajkomar, 2104). It should be retained for the design of HHDDs, but in the HHDD current market, there are still many HHDDs using opaque lines.
Another related point, reported by Allcock et al. (2012), is the importance of having clear colour-coding for the different ends of the dialysis circuit. The blue and red caps can help distinguish between the arterial and venous ends. Some HHDDs only have very small parts of the caps which are coloured, making it harder to distinguish between the two lines; this may cause a fatal incident that happened because a patient wrongly connected the ends of the circuit during the wash-back phase. These issues highlight the requirements to design HHDDs with consideration for patients’ limited capabilities. Failure to meet these requirements may lead to fatal accidents (Allcock et al., 2012; and Rajkomar, 2014).
3. Poor alarm system design
Thirdly, although incidents in which patients are harmed are currently infrequent, poor interface design can increase the likelihood of incidents occurring, in particular, the alarm system design. The observed problems with alarm systems included delayed, or no response, to alert events, or the alarm was not audible in all areas of patient’s environment. Other issues are difficulties in programming the alarm, where patients set it to inactive, or set it incorrectly. For example, a patient sometimes needs to switch to a different acid concentrate; however, when a different acid concentrate is used than the HHDD is programmed for the machine will alarm. The patient then has to reset the alarm a couple of times and only then can they proceed. Incidents with HHDDs have already occurred and coupled with the increase in patients requiring HHDDs in the near future, makes the improvement of the safety and usability of devices an urgent priority. It follows that the alarm system needs to be designed with the requirements of safety and user-friendliness in mind, as well as with an understanding of how the alarm system of HHDDs are actually used by patients in practice.
4. Low self-efficacy
Finally, patients, especially older patients, tend to have lower self-efficacy to administer HHD therapy. Self-efficacy in this context can be defined as the estimation of one’s capacity to engage in behaviours that contribute to desired health outcomes. Compared with other groups of people, older people tend to have lower self-efficacy, often due to lack of experience, which in turn leads to feelings of anxiety. For HHDDs, older patients do not believe they can learn to use them, and they lack confidence that they have sufficient expertise and emotional fortitude to use HHDDs. For example, patients repeatedly described the difficulty of having to learn how to operate an HHDD in conjunction with the added fears of self-cannulation. Almost all participants indicated they had a fear of needles. Additionally, patients also expressed fear and anxiety of a life-threatening event associated with HHDDs. In particular, patients who had experienced prior medical emergencies articulated potential problems with the adoption of HHDDs. Research has shown that up to 30 percent of patients with kidney disease suffer from clinical depression such as low energy, lack of appetite, lack of interest in social activities, and changes in sleep habits.
Therefore, when patients use HHDDs, an increased level of usage comfort and reduced anxiety and fear for patients should be provided. As the Life Options Rehabilitation Program found, positive attitudes and comfortable treatments regarding HHDDs can extend a patients’ life span. What is more, a user-friendly interface could strengthen patients’ confidence and positive emotions during their treatments. Patients should never feel intimidated by HHDDs.
5. Limited support for addressing these complications
Although there are a considerable number of design issues when patients interact with HHDDs, there are few published studies and little information readily available for designers, manufacturers and researchers.
Firstly, many surveys and studies are limited to gathering views on HHDDs, and some publications are limited to addressing interaction problems. What is more, most published analyses are on adoption barriers to HHDDs in the UK and have been limited by examining factors in isolation. Some qualitative studies of HHDDs are not systematic, and surveys lack consistent data as well as consensus. In addition, when studying home healthcare, researchers have described a lack of well-developed methodologies. It is apparent that there are significant methodological challenges when conducting rigorous research investigations in this area. Moreover, most designers are unfamiliar with the operation procedures of HHDDs when they design the devices. They typically have a limited understanding and contact with patients, especially older patients, which is the greatest inhibitor for designing effective, friendly, and safe HHDDs. Likewise, design approaches can assist designers to understand the interaction between HHDDs and patients. But there is limited information to support designers in developing a suitable approach.
Allcock, K., Jagannathan, B., Hood, C. J., and Marshall, M. R. (2012) Exsanguination of a home haemodialysis patient as a result of misconnected blood-lines during the wash back procedure: a case report. BMC nephrology, 13(28)
Farrington, K., and Greenwood, R. (2011) Home haemodialysis: trends in technology. NDT plus, 4(3), 23-24.
FDA (2010) Medical Device Home Use Initiative [Internet. Accessed April, 2010.] Available from: https://www.fda.gov/downloads/UCM209056.pdf.
Rajkomar, A. (2014) Augmenting Distributed Cognition Analysis For Home Haemodialysis: From a System of Representations To Systems of Activity-Centric Interactions. Unpublished PhD thesis. UCL: University College London