Human factors in your hands: Usability for more than just regulatory compliance
The world of medical devices has been combining user experience and the understanding of patient capability since the advent of IEC 62366, and the US Food and Drug Administration (FDA) ‘Draft guidance on applying Human Factors and Usability Engineering to optimize Medical Device design’. These have moved development on from purely solving the engineering problem towards resolving use errors and designing with the end user in mind.
Recently both the FDA and the European Medicines Agency (EMA) released guidance that promoted a more user-centred approach to pharmaceutical development. The FDA ‘Draft guideline on patient-focused drug development’ and the EMA ‘Reflection on pharmaceutical development of medicines for use in the older population’ suggest that regulatory bodies see the next step in drug delivery as considering the patient from the early stages of formulating new medicinal products.
For most patients the simplest way to take a medicine is an oral tablet. However, there is an increasing trend away from small molecules towards large molecule peptides and proteins with an overall move towards the delivery of Biologics. Their sensitivity to the ‘first-pass effect’ of the human liver limits delivery routes, with parenteral (injection-based) administration taking the bulk of the market share. Couple this with a preference for self or caregiver administration away from a hospital environment and an increased drive towards patient-related outcomes. It then becomes clear that a product that can reach the intended site of action with the correct dose at the right frequency cannot be achieved without serious consideration of the intended user and recipient.
In the devices’ world the process around determining if the user can operate the device safely and effectively is well established. Firstly, consideration is given to their capabilities, such as their manual dexterity and grip strength. For example, whether a Rheumatoid Arthritis patient has the finger or hand dexterity to press a button to deliver their medicine with an auto-injector. This is documented within the Use Specification for the device. Then usability studies conducted throughout a device’s development (i.e. Formative evaluations) where real people simulate use, allow knowledge of how people approach a device to be fed into the design process so it can be as intuitive as possible. Lastly usability validation or summative studies test the device with a representative population of users to confirm that the final version and its labelling can be used safely and effectively.
Historically, pharmaceutical products that don’t have a device element have not needed to consider the end user to the same extent, and the focus has been on developing a stable formulation. As an example, an older patient suffering from dysphagia (difficulty or discomfort in swallowing), where solid tablets may stick in the throat or may just be too big, may have several options. These may include water dissolvable tablets or powders, capsules that can be opened to allow sprinkling of contents over food or tablets that can be broken in half for easier distribution. At first glance, these provide different solutions for dealing with the difficulties. However, different formulations may result in an increased cost to the patient (cf. the cost of solid tablet paracetamol vs dispersible paracetamol in the UK) or even need a different way of administration of a tablet that, on the surface seems identical. (for example comparing a water dissolvable tablet with one that dissolves on the tongue). Patient information leaflets and instructions are not always read or understood, especially with repeat prescriptions of what may seem to be the same medicine. This may result in the patient taking their medicine in the wrong way with the potential for varying results. So the best option for the user may in fact be a completely different presentation that makes differences obvious.
Underlying this is the evolution of drug delivery technologies with new capabilities such as 3D printed medicines and custom-made solutions for individual user needs. Patients are becoming more informed about their treatment and these resources can also play a part in the reduction of user error and improving patient outcomes.
Whilst every problem is not necessarily solvable through the patient-centred-design of the formulation, factoring it into the development process at an early stage should allow for potential shortfalls to be addressed with an appropriate management strategy.
To learn more about how human factors usability engineering can benefit healthcare product development, watch our webinar with Louise Place (Head of Regulatory Affairs) and Lucy Sheldon (Human-Centred Design Consultant).