Home testing is not new.

Pregnancy tests are a great example of a mass-based home testing kit that has adapted for ease of use and is so ubiquitous it probably isn’t seen as a home diagnostic. My guess is that most women in the Western world have used a home pregnancy test with the hope of a positive or negative result at least once in their adult life. Pregnancy tests have, of course, come a long way since when they were first available in the 1970s, both in terms of speed of results, reduction of steps and clear information to the user. You can read an interesting history of pregnancy tests here and there is a great recreation of using a home pregnancy test in the 1980s in the Netflix series Glow:

Ruth’s test in the Glow series probably took about 20 to 30 minutes compared with 2 minutes for a modern test and there are now no complex steps or mixing. “Just” pee (of course accuracy is needed) on a stick and wait. The potential for error is now in the interpretation of the results. In the film Juno, the main character re-did her pregnancy test over and over claiming that they must be “defective” or the “plus sign looked more like a division sign”. I know from personal experience that I had to double check what the different symbols meant. Is plus good or bad? It depends what you want the outcome to be of course.

I was obviously not the only one who was getting confused or lacking in confidence of the results. Marketers latched on and now many pregnancy tests have the code printed on the outside and of course you can a get a digital pregnancy test that will tell you whether you are pregnant by displaying the words “pregnant” or “not pregnant” on digital display to avoid any confusion.

Working in a technology consultancy I learnt that the internal workings of the digital pregnancy tests were the same. The digital ones just used the electronics to interpret the results of a normal test kit rather than doing the actual test. The BBC also a wrote about this in 2020 here. So when I was potentially pregnant with my second child I bought the cheapest pregnancy test strips you can get, which just comprise of a paper strip with no plastic housing. There was no single use battery and electronics and extra plastic and an overall smaller package. Of course it did require me to have the confidence that something so simple would give me the same results as the fancy test that cost over 10 times as much, which I had because I knew people who had worked in that industry. And it did require a bit more reading of the instructions, which I did because I was invested in getting the right results based on my decision to choose that type of test. But given the overall “cheapness” of the packaging and rarity in supermarkets or pharmacies I’m probably one of the few people who go down that route.

I was reminded of this experience in considering the waste for the lateral flow tests. The pregnancy test falls into a consumer-based choice where customers are enticed by “quicker”, “easier” etc. But at what cost? Both to the consumer and the environment. As more tests are sent to home users these are questions, we need to consider carefully whether they are in response to a global pandemic or for mass screening. Meaning there is even greater need to consider how design both of a home test kit and the instructions can make the end user feel confident about the results but also minimise waste and avoid unnecessary packaging.

If you want to learn more about developing and testing good instructions for use see our services here.

References

https://history.nih.gov/display/history/Pregnancy+Test+Timeline
https://inspiredusability.com/2021/08/10/lateral-flow-testing-for-covid-19-a-positive-human-factors-experience/
https://www.bbc.co.uk/news/technology-54025997
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Lateral flow tests are becoming part of the new normal in the ongoing COVID-19 pandemic. I first got access to the tests as a parent of 2 primary school children but they are now becoming common for all adults in workplaces throughout the UK. While there is debate at the effectiveness of lateral flow testing, as someone who works in the medical device industry, I’ll take any opportunity to experience using new medical developments first-hand.

Opening the first box of lateral flow tests reminded me of one of my first Human Factors projects as a consultant in 2008. I was running a usability study in which users had to perform a home-based glucose tolerance test. The users had to prick their finger with a lancet, place the blood drop onto a sensor, drink a glucose drink, wait a period, then take a second blood sample, place it on a sensor and then finally send the samples back to a lab for analysis. The system was paper-based and it quickly became clear through user testing, how important all the different parts of the device were. We spent time (and blood) trying to figure out which was the most intuitive lancet for naïve users, and quickly found out that many lancets were not obvious to use. We also had to figure out how everything would be packaged together, so that users would have easy access to all parts of the test when they received it in the post.

Testing home kits was challenging

One of the biggest challenges of usability testing the home kits was communicating to users where and how to place their blood since this had to be very precise. There were numerous iterations of the overall design and instructions and many formative studies were conducted before we felt confident that we had a design that would work in real-life. For me, it was a lesson of how subtle changes to the design can have a big impact on usability and how user testing is imperative to help make decisions about these changes.

Eliminating risk is crucial

Medical device development follows a risk-based approach to ensure the design is safe to use. Standards such as IEC 62366-1: 2015, ISO 14971: 2019, FDA Applying Human Factors and Usability Engineering to Medical Devices: 2016 and MHRA Guidance on applying Human Factors to medical devices: 2021 follow the process shown below.

The FDA describes the best ways to eliminate risk in order of preference as follows:

1. Inherent safety by design – For example:
• Use specific connectors that cannot be connected to the wrong component.
• Remove features that can be mistakenly selected or eliminate an interaction when it could lead to use error.
• Improve the detectability or readability of controls, labels, and displays.
• Automate device functions that are prone to use error when users perform the task manually.

2. Protective measures in the medical device itself or in the manufacturing process – For example:
• Incorporate safety mechanisms such as physical safety guards, shielded elements, or software or hardware interlocks.
• Include warning screens to advise the user of essential conditions that should exist prior to proceeding with device use, such as specific data entry.
• Use alerts for hazardous conditions, such as a “low battery” alert when an unexpected loss of the device’s operation could cause harm or death.
• Use device technologies that require less maintenance or are “maintenance free.”

3. Information for safety – For example:
• Provide written information, such as warning or caution statements in the user manual that highlight and clearly discuss the use-related hazard.
• Train users to avoid the use error.

As you will have noticed in the FDA Human Factors guidance, information for safety is often seen as the third or least preferred option. But in cases such as a home diagnostic, the instructions for use (IFU) becomes integral to the design and therefore is not simply a separate control measure but part of the design itself and requires rigorous testing and consideration of Human Factors.

A well written and designed Instructions for Use

I’ve seen a lot of poor Instructions for Use (IFUs) and Quick Reference Guides (QRGs) accompanying home kits over the years, both as a consumer and a Human Factors consultant, and I’m pleased to say that the NHS COVID-19 lateral flow test is not one of those.

Some of the key design elements of the instructions are:
• Information is broken down into steps which are easy to digest and presented under clear section headings
• Good font size and use of white space
• Concise sentences written in plain English
• Line drawings which clearly represent the test kit
• Appropriately sized booklet which is easy to handle
• Alternative ways to view the instructions are available – including watching a video or easy read and large print guides.

Inspired Usability can help with the design, usability testing or expert review of instructions for use and quick reference guides. For more information, see our website.

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The response to this was, “Isn’t that a bit idealist?” I was no Greta Thunberg, so I probably just looked blank and that ended the interview. My feelings were piqued and on leaving, a response then formed in my head, “If I can’t be idealist when I’m 18, when can I?”. Needless to say, I didn’t get the scholarship.

I don’t know the intention behind the question the middle-aged white man posed to a young woman keen to start a career in engineering. Maybe he wanted me to show more fight and conviction in my choice of career, or maybe he had become disillusioned with his own work. I’ll never know, but I’m very glad that that comment didn’t deter me from working in the medical field. I have spent around 16 years working on products linked to healthcare. First as an engineer/designer and then as a human factors professional specialising in medical devices. And while I can get frustrated at red tape or feel that progress is slow, I am always glad that I have chosen to work in this field. I can’t claim to have made any major discoveries, but I do like to think that my input has been overall for good.

For example, since the pandemic started, Inspired Usability has provided input into guidance on usability testing of Rapidly Manufactured Ventilator Systems for Chartered Institute of Ergonomics and Human Factors, provided final human factors submission guidance for a novel device for cancer detection, worked on the human factors activities for new drug products that include a new cancer treatment and biosimilars for pediatric and adult patients and conducted human factors studies providing advice on 4 new drug delivery platforms that are not yet on the market with a range of benefits to end users (as well as adapting to working under Covid-19 restrictions).

On Sunday, I was reminded of the man in the interviews and his comment when I sat in the Yorkshire Showground Pavilion after receiving my first Covid-19 vaccine and waiting for 15 minutes to pass by before going home. I felt humbled by all the other people who had chosen to work in a field that can truly make a difference. I felt humbled by the fact that over 100,000 people had sat in that same waiting area before me. Because there are so many amazing feats of medicine, science, engineering, human factors, logistics and more that brought me to that waiting room. Of course, there were people who had the foresight to start planning on how to make a vaccine in record time when needed and the massive ramp-up in production and logistics but there was also all the work that went into the very running of the vaccination centres around the country.

My own customer journey was an amazing piece of human factors, from booking my slot on my phone based on my date-of-birth and postcode, driving up to the Showground with precision way marking, parking guided by expertly choreographed volunteers, hand sanitising, double identification and check-lists and finally the warm smile of a proud volunteer pointing out the golden balloons with the numbers 100,000.