Patient safety and interactive medical
devices: Realigning work as imagined
and work as done
Abstract
- Introduction
- Usability in practice
- Aligning device design and use
a) Significant issues can arise if medical devices are designed for ' work as imaged' when this is misaligned with 'work as done'
b) Current regulation involves a series of pre-market checks relating to device usability, but this assumes that devices are always used under the conditions and for the purpose intended (ie work as imagined)
a) Human factors take a broad approach to improving the performance of systems of people, processes, products and policies
b) We aim to raise awareness of another significant aspect of human factors that has received less attention in health care: the design and use of interactive medical devices
c) In this article, we highlight the importance of going beyond evaluation of usability to ensuring that device design and use are aligned, so that systems are fit for purpose in practice
USABILITY: BETWEEN USER ERROR AND DEVICE ERROR
I) When an incident involves a device, it is most commonly categorized as either user error or device error. The cause of an incident is normally classed as a device error if there is some fault in hardware or software. If the device performed as designed then user error is assumed: the problem must be something to do with training, inattention, incompetence or failure to read instructions
this simple attribution as either user error or device error fails to raise questions about the suitability of the design itself, and whether design and use are misaligned
usability and fitness for purpose lie in the interaction between the user, the device and the context of use
ii) However, usability engineering as part of pre-market approval is necessary but not sufficient for ensuring fitness for purpose in practice
a) Eg 1: the use of infusion devices- operation takes 8 key presses- such a mismatch between local practices and the design (or configuration) of the medical device may not be inherently error-prone, but it adds to staff workload in an already stressful environment and draws attention away from the core task of patient care.
b) Eg 2: Another kind of difficulty emerges in the "unremarkable errors" which are little, every-day errors that clinicians barely regard as errors because they are minor and are quickly recovered from. They draw attention away from other aspects of clinical work
c) one important way in which poor fit becomes apparent is identifying workarounds in use
d) Workarounds typically arise because, in the here-and-now of work, they offer a timely solution to delivering care, and they are overcoming some mismatch between the design and the needs of use
e) Sometimes, devices are used for purposes for which they were never designed.
f) When devices are appropriated for uses for which they were not designed, this introduces vulnerabilities into the system.
g) Consideration needs to be given to whether the tasks that need to be done can be achieved safely using the available tools.
h) workarounds often become normalized in clinical practice, despite the fact that many of them introduce vulnerabilities into the system by eroding safety mechanisms (e.g. increasing the risk of patient misidentification or confusability of devices, or circumventing safety checks that were designed to catch errors).
i) The most effective way of identifying these practices is through observation by an ‘outsider’ for whom these practices are not taken-for-granted knowledge and who is experienced in studying clinical work and people’s interactions with technology.
a) There is a need to review actual clinical practice and the fitness for purpose of devices in supporting that practice, as a form of post-market evaluation. 15 This would be typical in other industries: for example using a safety management system and safety case documentation.
b) The quality of fit can be improved through careful selection of devices to match needs, or by working closely with clinical teams to ensure that practices evolve to match the assumptions embodied within design;
c) The purchasing process for medical technology represents one opportunity for optimising this fit, by taking account of human factors for equipment and of current clinical practices so as to reduce risk.
d) Further decisions are made about how devices are configured and the protocols for clinical use.
e) Fitness should also be monitored as contexts and needs change.
f) In summary, human factors has an important role to play in device design and use, and usability testing as part of pre-market approval is necessary but not sufficient.
g) Improved safety requires coadaption of technology, i.e. continual refinement and
eview, likely to involve those using equipment as well as those supplying it
h) Usability and fitness for purpose should be a focus during procurement, configuration, deployment and use; patient safety can be improved through regular review of needs, practices and designs to ensure that device design and use is aligned with clinical practice.