A great device is only as good as its instructions for use!
We often get involved in studies at the validation stage of the verification process. At this stage, it becomes more difficult for manufacturers to amend the design of a medical device and the value of doing a formative study is put into question from a financial point of view. However, it is easy to overlook one user interface that could have a significant impact on the safe, efficient, and effective use of a medical device. And interestingly, for most devices this also tends to be the easiest and cheapest interface to change. Off course, we are talking about instructions for use (IFU) or for more complicated devices, the user manual.
Even when a lot of effort has gone into the design of an IFU with the information and tasks are well laid out, organised and accompanied by explanatory graphics, the information and corresponding user behaviour can still be unexpected. These phenomena have been seen time and again in our usability studies. Also, differences within and between user groups have an impact on how the information is interpreted and the actions that follow. The question then is, how can we identify and rectify this?
Pre-summative and formative usability studies highlight which aspects of an IFU should be changed to make it easier for users to understand how to interact with the device. Often patterns emerge that can be traced back to specific tasks or a series of tasks in the IFU that were not clearly understood or that required an explanation to motivate the user to act on them. Investigating the root causes of use errors, difficulties and close calls shed a light on how and why the information was understood differently by the user.
Understanding why specific instructions were not clear or interpreted differently, means that these instructions could be reframed to make them more accessible for a larger group of users. Also, where the design of a user interface cannot be changed, the IFU could help to mitigate against use errors by identifying these and providing instructions that support safe use.
As a relatively cheap and easy interface to change, pre-summative and formative studies on IFUs could reduce use errors. Even though IFUs cannot be a sticky plaster for bad device designs, they form an integral part of how the user interacts with the device. To enhance their usability and to reduce otherwise avoidable use errors, they require exploration before the validation process.
