Recent decades have seen the steady growth of clinical diagnostic tests that can be used at home, at pharmacies or general practitioner (GP) practices (St John and Price, 2014). From home pregnancy tests to Fitbits and smart watches, the analytical chemistry and analysis technology has been miniaturised and automated, allowing an increasing range of tests to be taken outside laboratories and hospitals, and brought into the community. Following the roll-out of regular home and workplace testing for COVID-19 during the pandemic, an initial dramatic scale-up of centralised testing was followed by widely publicised mass-testing. Following early pilots exploring the accuracy of rapid lateral flow tests (LFTs), the UK Government purchased and distributed tests into the community before publication (BMJ, 2021: 374 n1637). Educational testing was prioritised (in higher education from November 2020 and in schools from January 2021) and subsequently, rapid tests for home use were distributed freely; for example, from most community pharmacies by April 2021 (gov.uk, 2021).¹ To accompany the tests, different kinds of instructions explained to people how to carry out an LFT. These tests usually involve taking a sample from your nose and/or mouth, using a swab. The swab is then mixed with a solution and drops are put into a special device. The results are available in ten to 30 minutes depending on the kind of test. Instructions for these tests range from booklets that accompany National Health Service (NHS) and government testing kits, to videos, animations and posters produced by people of all ages from many different backgrounds and with different experiences. During the pandemic, many people learned how to carry out a test – and became proficient and confident about carrying it out accurately. In the near term, more use of lateral flow tests for community infections such as influenza can be expected. Many community testing services were established during the pandemic for remote monitoring, especially for managing long-term conditions. Many of these have been retained beyond the pandemic, as patients and clinicians alike prefer point-of-care testing to a return to slow and inconvenient hospital clinic visits. As more community testing takes place with new point-of-care tests, more and better instructions will be needed to ensure the tests are carried out safely and accurately.

This chapter intervenes in this landscape, through a study of the design and usability of instructions for point-of-use COVID-19 lateral flow rapid tests. At its heart is an argument that such tests don’t simply need better instructions, but that we need a richer, more nuanced account of what is meant by ‘good instructions’ in the first place. We start by outlining the differences between ‘instructions for use’ and ‘point-of-use’ instructions and draw from existing design research to argue the benefits of simple instructions for point-of-use. After explaining our approach and summarising our methods, the focus turns to our exploration of design features to create effective point-of-use instructions. Although focused on current lateral flow rapid tests for COVID-19, the findings are applicable to any community-based testing technology and medical condition. In particular, we describe the development of a toolkit to support the creation of point-of-use instructions, taking account of views from diagnostic industry members to inform an understanding of how instructions are produced currently and what guidance might be helpful. The chapter outlines unresolved tensions between the needs of final users and the constraints posed by needing to meet regulations within timeframes. The benefits of user-friendly point-of-use instructions can be leveraged not only in home tests, but also in community testing settings, to be used by healthcare professionals as well as patients.

Why are instructions so critical for community diagnostic testing?

What makes these instructions for point-of-care diagnostic tests especially critical is the big jump between laboratory testing versus out-of-laboratory alternatives that adds significant pressure to the quality of these instructions (Figure 3.1). Laboratory testing is supervised and controlled by teams of highly trained staff, with a range of quality control and certification processes in place, and many laboratory tests have regular calibration or checking processes to ensure that tests are operated correctly. The operation of such tests is less dependent on the clarity of instructions, and many more layers are in place to ensure results are accurate and the testing process is safe and effective. In contrast, home or community-based tests rely on non-trained users, often without any checking or training. This places great pressure on the quality of instructions to substitute for expert supervision.

Figure 3.1Laboratory testing versus point-of-care testing

Procedural instructions for diagnostic tests: an overview

All diagnostic tests have to include ‘instructions for use’ (IFUs), produced in line with a regulatory framework of principles that includes general guidance about the structure of information and its visual organisation (IEEE, IEC and ISO, 2019). This guidance for setting out instructions aligns with good practice, but tends to be applied with little consideration of the needs of final users, and the information is often embedded in a leaflet that contains other regulatory information (aimed at laboratories, expert users, or information required for liability reasons). Upon inspection, the graphic presentation of information and the different kinds of information contained in some IFUs suggest their role as documents for risk control and liability management, rather than vehicles of clear information designed to improve user experience. Figure 3.2 shows a typical IFU annotated to indicate the parts that challenge ease of use for lay first-time users. Cherne et al. (2020), who examined how healthcare professionals, patients and lay caregivers engaged with IFUs, included ‘design elements’ in their review. They found that bulleted lists, pictures and logical organisation engaged users, whereas too much text, small type and lack of clear structure to the information were thought to be off-putting. These observations support an established view that good information design can help by making sure that information is clearly structured and understood so that it can be acted upon (Dickinson and Gallina, 2017; Tong et al., 2014; Walker, 2017; Waller and VandenBerg, 2017).

Figure 3.2COVID-19 self-test

Our research investigated the design and ease of use of instructions for carrying out COVID-19 LFTs at the point of use. Unlike the mandatory IFUs specified by regulations, point-of-use instructions take account of the needs of intended users and are designed to be easy to read and follow. Design features that reduce the effort of readers include ensuring that there are clearly identified sections and procedural steps, the action steps are explained through words and pictures, and the text is easy to read. This is affirmed by observations from Atchison et al. (2020) who, in relation to instructions for COVID-19 tests, found that diagrams with clear visual cueing and simple language helped lay users, and Kierkegaard et al. (2021), who reviewed the quality of information supporting LFTs, and suggested that more attention should be paid to the information needs of lay users and context of use.

There is already considerable knowledge about how people use and interpret instructions, the types of information they need and best practice for the visual organisation of text and image.² We reviewed and applied this work as appropriate to explore the graphic presentation of parts of the test where mistakes were made and that then affected test accuracy and validity.

Information design approach and methods

The project, Information Design for Diagnostics: Ensuring Confidence and Accuracy for Home Sampling and Home Testing, combined information design research and practice with bioscience research. The project team included partners in the diagnostic testing industry and public health. The bioscientists brought understanding of the chemistry and working of the tests and, importantly, had a vision for the future relevance of community-based diagnostic testing. Information design research, in relation to health communication, as Walker has noted elsewhere (2019: 2), contributes by:

• considering the selection and presentation of the information provider’s message in relation to the purposes, skills, experience, preferences and circumstances of the intended users;
• co-designing with information providers and intended users in the development of prototype solutions;
• finding out whether protypes in development or completed documents work for their intended audience and circumstances of use through qualitative and quantitative methods;
• offering creative solutions to the visual organisation of information through the treatment of the text and the design.³

We followed a process well established within information design of Discovery–Transforming–Making (Waller and VandenBerg, 2017), consisting of exploring the problem and identifying areas where the visual organisation of text and images may present difficulties for readers, developing a range of solutions, and, through evaluation, narrowing down to prototypes. Our project used a ‘rapid design decision-making’ process to identify and explore the design features that improve instructions for members of the public. Evidence from user research and existing best practice informed the design of a prototype for point-of-use instructions for a COVID-19 lateral flow test. Working with members of the in-vitro diagnostic testing industry, we applied our prototype to see how our approach could be transferred to other kinds of tests. Semi-structured interviews were conducted to gather industry members’ views of the importance of instructions for use, and to better understand the applications of a design toolkit. These stages of the projects are covered in the following sections.

Prototype development: rapid design decision-making

In a previous study with low-cost 3-D printed home-testing kits, bioscience members of the research team had found that when they carried out tests with users to check ease of use, instructions for using the kit they provided needed improvement (Needs et al., 2020). They identified the parts of the test that needed to be carried out correctly to ensure accurate test results. For the purposes of this project, we were therefore able to narrow down the variables we could realistically evaluate given our time constraints. Areas that appeared to cause problems were procedural steps that included actions such as ‘squeeze’ and ‘rotate’, that are difficult to describe in words and pictures; putting the correct number of drops in the test device; and interpreting the results. This work informed the focus of the design approach, which used a range of techniques to enable rapid design decision-making. This comprised a review and distillation of existing research, stakeholder engagement and application of tacit information design knowledge (as two members of the research team were practising designers) (Figure 3.3).

Figure 3.3Overview of techniques to enable decision-making in the design process (Walker et al., 2022)

The rapid design decision-making has been explained elsewhere (Walker et al., 2022), but exploration of illustration approaches to represent the action steps is summarised below.⁴

Stakeholder engagement: exploring illustration approaches

‘Rotate’ and ‘squeeze’ are important and relevant actions in diagnostic LFTs, so as part of our prototype development, we asked our user panel⁵ for feedback about different versions showing the use of arrows to denote actions: ‘rotate the swab’ and ‘squeeze the tube’. As part of our iterative design exploration, we invited some members of the panel to explain the meaning of a set of diagrams, and to tell us their preference between alternative approaches. Fourteen people participated (seven women and seven men), who were between 27 and 81 years old. Data were collected using an online questionnaire distributed by email.

• ‘Rotate the swab’. Four versions were designed to indicate ‘rotate the swab’ in the liquid in the tube (Figure 3.4). The feedback affirmed that all the options conveyed a ‘rotation’ action overall. However, some participants noted that A and B could be interpreted as ‘up and down’ or ‘back and forth’, and that D had an added focus on multiple rotations. The multidimensional arrows C and D were preferred over A and B to represent an action in a three-dimensional space. A further set of diagrams was produced showing the use of a ghosted shape to represent movement, in addition to an arrow (Figure 3.5). Thirteen out of fourteen people preferred a diagram showing the swab in ghosted form. This suggested that using a ghosted shape was effective to explain how to move the swab when no hands were depicted.

Figure 3.4Different versions to indicate the action ‘rotate the swab’

Figure 3.5Examples B and C show versions of ‘rotate the swab’ using a ghosted shape

• ‘Squeeze the tube’. A further set of diagrams showed four versions of arrows to denote ‘squeeze the tube’. There was a clear preference for B, which seemed to be the best for indicating movement (Figure 3.6). It suggests that ‘squeeze’ is best depicted by vertical gaps in the stem of the arrow rather than changing its shape.

Figure 3.6Different versions to indicate ‘squeeze the tube’

Another factor in the representation of actions is whether it is clearer with no hands, one hand or two hands shown. A set of diagrams was designed to show the actions ‘rotate the swab’ and ‘squeeze the tube’ showing no hands, one hand or two hands (Figure 3.7). There was a clear preference for the use of two hands, suggesting that this is an effective way to embody the action and provide useful information for viewers. This follows existing research on the design of instructional diagrams (Szlichcinski, 1984). As one participant commented: ‘The use of hands combined with arrows leaves absolutely no doubt about the intended message’. However, including one or two hands limits the scale at which the tube can be shown, which may make it less easy for users to interpret.

Figure 3.7Different versions of the actions ‘rotate the swab’ and ‘remove the swab while squeezing the tube’ showing the actions with no hand, one or two hands

Informal feedback from our user panel and information design good practice were used to make a prototype of new COVID-19 LFT instructions, shown in Figure 3.8. The action steps are explained through words and pictures, the text is easy to read and colour is used consistently. The sections of the test are clearly identified:

• Set-up information to explain good practice in getting ready to do the test:
  • Items contained in the test kit. This has an inventory function, prompting users to check they have a complete test kit, and helping them to identify each item in advance of using them.
  • Actions to be done before starting the test.
  • An overview of the procedure or a summary of the main goals.
• Instructions for carrying out the test:
  • A step-by-step explanation of actions necessary to complete the test. Includes feedback information so that users can monitor and check their progress.
• Results and what to do next:
  • A clear explanation of what the test results mean and actions to be taken.

Figure 3.8Prototype point-of-use instructions for COVID-19 lateral flow tests, developed using evidence from the research project and established knowledge in the design of instructional texts. Annotations refer to use of colour in the prototype (shown here in greyscale).

The articulation of these principles as shown in Figure 3.8 reflects good information design practice and takes account of the views of our user panel. This panel comprised people with good command of English and with no identified learning needs. For people with specific learning needs, visual impairment or particular language requirements, more work would be needed to ensure that the language used, typography and images took account of this (Hartley, 1994; Leat et al., 2016; NHS England, 2018; Peters et al., 2016; Terras et al., 2021).

Applying the research findings to new circumstances of use and products

We wanted to see how the design of prototype instructions for point-of-use COVID-19 tests could be applied to other kinds of test. We worked with Roche Diagnostics Ltd and the Health Innnovation Agency North West Coast (AHSN) to apply our design approach to a set of documents explaining how to use a test for viral flu.⁶ Roche and AHSN identified the Standard Operating Procedure (SOP) and Internal Quality Control (IQC) as key texts that needed improvement. The SOP and IQC would be used by health professionals in GP surgeries, outlining the steps they need to follow when administering tests for viral flu so that each patient is treated in a consistent manner, and including instructions for carrying out the test. We agreed to produce user-friendly instructions for a viral flu lateral flow test to form part of a procedural handbook, and a ‘quick guide’ version that could be positioned, for example, on a wall for easy reference. In applying our approach, we:

• reviewed the manufacturers’ regulatory instructions for use to identify the main steps relevant to the Standard Operating Procedure;
• carried out the test to understand the main actions and how to perform them;
• identified the kit components and made drawings in the chosen style;
• drafted wording;
• and set out text and images using the format in our previously-made prototype.

The mode of work was collaborative and iterative: the design team shared successive draft versions with the team at AHSN and Roche Diagnostics. In response, AHSN and Roche team members who were also healthcare workers gave feedback on the structure of the information, the wording and the images. The final version of the SOP is shown in Figure 3.9.⁷ The annotations indicate the key things that health professionals carrying out the procedure need to know. These were used as sub-headings, highlighted in orange bands in the document, while the action steps for carrying out the instructions, in this case of lower precedence, are less visually prominent in light blue.

Figure 3.9Application of the approach to an SOP (Standard Operating Procedure) to operate a lateral flow test for influenza

We also produced a ‘Quick Guide’ version, shown in Figure 3.10, using the same graphic conventions as in the full SOP version, but with edited text and illustrations to include just the key elements. The same approach was applied to the IQC, a procedure that GP surgeries receiving testing kits need to carry out for each box of tests (Figure 3.11).

Figure 3.10SOP Quick Guide, with edited text and illustrations to include the key elements

Figure 3.11Internal Quality Control (IQC), using the same conventions, including horizontal bands to separate the component parts. To distinguish it from the SOP and Quick Guide, a different colour is used for the key steps

The application of our initial prototype demonstrated it could be used effectively as a design template, but while our prototype was most directly applicable to the SOP, variations were required to produce the Quick Guide and the IQC. The underlying principles for organising the information and main components provided a strong starting point; for example, using colour to signal subsets of documents, compressing and simplifying the procedural steps in the Quick Guide, engagement with experts to understand the stages of the protocol and draft simple text and messages accordingly.

A toolkit for making point-of-use instructions

The application of the approach to proposed diagnostic tests for viral flu affirmed our intention to support manufacturers and distributors of tests and service providers to make testing easier and safer. Manufacturers of diagnostic tests are required to follow a regulatory framework for instructions for use. These are detailed and follow British and European principles and general requirements, and tests often include such regulation-required instructions as a pack insert. Previous engagement with manufacturers (by bioscience members of our team) had indicated that traditional Instructions for Use were not seen as easy to use, and there was an appetite for instructions fixed to the principles and guidance of the regulatory framework but made with the needs of users in mind.

We set out to produce an evidence-based practical guide for manufacturers in the form of a toolkit, aimed at diagnostic companies who want to commission point-of-use instructions, and at design professionals who are unfamiliar with the design of procedural instructional text. Similar to instructions for use aimed at the general public, the design guidance needed to be delivered in a way that was quick to search through, easy to understand and simple to apply. We developed an initial draft of the toolkit, to use in semi-structured interviews with regulation implementers and test delivery service providers. The aim was to gauge industry views about the focus and relevance of our approach.

Five professionals in point-of-care diagnostics were contacted through professional networks. All were working in the UK, developing and/or providing service delivery of different types of tests, including lateral flow tests. Semi-structured interviews were conducted online to understand whether they and their companies recognised the importance of point-of-use instructions, and to explore what guidance they would find helpful.⁸ The interview was structured in two stages:

• Initial questions aimed to establish their views about the role of user instructions (‘How much attention does your organisation/you pay to instructions for diagnostic tests [for home use]?’, ‘Do you review the instructions that come with the test [i.e., the manufacturers’ instructions for use] before distribution? Why?’ ‘Can you explain what you’re looking for?’ ‘What do you do if the instructions look unacceptable?’).
• Then, interviewees were shown sample pages of the draft toolkit, and asked about the perceived usefulness of such an approach (‘We are producing a set of guidelines – a toolkit – to explain how to produce Point of Use instructions. This is an example. How would something like this work for you? What is missing? What do you like about this and why?’)

Due to the small number of interviews, the responses were transcribed and recurrent views were summarised. It is not assumed that these views represent all manufacturers and service providers. However, the contributions of interviewees inform our understanding of competing requirements that affect the way in which crucial user information is communicated to non-expert audiences that operate the tests.

Suitability of IFUs for lay users – When discussing the suitability of IFUs for lay users, there was widespread recognition of the difference in purpose and audience between IFUs and point-of-use instructions, and that IFUs are not designed to be first and foremost easy to use. There was general understanding that instructions for expert and non-expert users have different requirements, and that information that would satisfy the regulator would not necessarily satisfy the non-expert final user. One interviewee commented: ‘There are plenty of regulatory requirements which I don’t think add value to the end user, but are required from a legal standpoint, definitely.’

Initial reactions to toolkit approach – When shown draft sample pages from the toolkit, interviewees’ comments suggested that the content was relevant and could be used by members of the industry looking to produce user-friendly instructions: ‘it provides a really good framework from which to start’; ‘it’s really valuable work’ and ‘I am absolutely certain that what you’ve done is useful’. The sample pages included recommendations about plain language, short text and clear diagrams, which the interviewees agreed with and highlighted as important points to get across. Perhaps unsurprisingly, interviewees supported the use of illustrations to assist with explanation and remarked that long text is likely to dissuade readers from engaging. They pointed out that clear diagrams are important to make the instructions inclusive; for example, for people with different reading and cognitive abilities, and for speakers of English as a second language.

Important aspects to include – When asked for further aspects to cover in the toolkit, two interviewees pointed out that point-of-use instructions should communicate the implications of possible errors for the final user. There was a sense that, in addition to showing the correct actions, good instructions should be clear about key actions, the implications of not doing them and include warnings and troubleshooting. Two participants commented: ‘You’re not telling people just what to do, you’re trying to avoid key errors as well’, and ‘sometimes, the people who design [these tests] give very little information about the impact of not doing something’.

The resulting feedback has been incorporated into a toolkit comprising three main sections, which provide guidance on engaging with intended users, treating content and structure and using illustrations and text in point-of-use instructions (Figure 3.12). The purpose of the toolkit is to:

• encourage test manufacturers and suppliers to consider point-of-use when creating instructional documentation for their tests;
• support manufacturers and distributors of tests in the preparation of point-of-use instructions to suit specific audiences and circumstances of use;
• and implement user-centred design research and practice in producing instructional documentation for users.

The recommendations are supplemented by references to existing research, examples of how the guidance has been applied to non-COVID instructions and examples of good practice in procedural instructions (Walker, Bravo and Edwards, 2022).

Figure 3.12Pages of the toolkit ‘User-friendly point-of-use instructions for home use diagnostic tests: guidance and tools’. Each page in the toolkit summarises key issues and provides captioned or annotated illustrations to explain the key points

Research-informed guidelines such as the toolkit can raise the profile of point-of-use instructions and support the creation of user-friendly instructions. However, guidelines are, by nature, non-prescriptive and hence open to interpretation.⁹ Even if design guidelines are followed to create point-of-use instructions, some form of testing with end users is required to assess whether the resulting document meets the users’ needs. While end users have been involved throughout our project, we have not yet taken full account of specific user requirements, including the needs of final users of instructions for whom English is not a first language, older people and people who are partially sighted. Engagement with such groups would most likely result in different prototype solutions, perhaps with text in two languages and captioned images; or with adjusted typography. The underlying principles in the toolkit would be relevant in helping the design decision-making in relation to such user groups.

Concluding remarks

Our investigation into the design of procedural instructions for diagnostic tests has identified the critical importance of these instructions, noted some barriers and complexities and delivered a framework for future community test products. Our work has not only affirmed the need for and value of instructions at point-of-use, but also provides insight into why these are especially important for community testing.

When our project started, COVID-19 home testing was becoming part of everyday life, and instructions for carrying out tests were being produced by professionals, by lay people and in a number of formats. While such instructions enabled people to carry out tests effectively at point-of-use, research into the effectiveness of COVID-19 rapid tests drew attention to parts of the test that were especially vulnerable to procedural errors, and that could result in invalid results. Our research investigated how to represent some of the actions – such as rotate a swab and squeeze out a specified number of drops – that people found difficult in the context of carrying out an LFT at home. The resulting prototype for instructions drew on this research and applied established information design good practice.

Our research-informed guidance for producing point-of-use instructions – in the form of a toolkit – aims to help diagnostic test manufacturers and service providers produce user-friendly instructions. The key messages in the toolkit are: work with users and get their feedback about draft versions; keep key messages straightforward and clear; and use images to help explain procedures. This toolkit exemplifies what is ‘good design’ for user-friendly procedural instructions.

The time is right for such guidance, not least because of a likely increase in the use of home- or community-use diagnostic testing kits going forward. For some respiratory infections, such as COVID-19 or influenza, antiviral drugs can significantly reduce disease severity, and home treatment is possible as these are administered orally. Crucially, treatment is only effective if the correct drug is administered soon after symptoms start. Lateral flow tests from saliva or swabs have therefore great potential to target antiviral drugs specifically to vulnerable patients.

The project did not focus on ways to change regulation on IFUs. Our approach was to explore ways to meet the needs of patients by producing documents targeted at specific audiences. For example, in applying our approach to the SOP for viral flu, the decision was made early on not to interfere with the traditional SOP (containing regulatory information) and, instead, produce visually informative documents that could be used at point-of-use, and inserted into the larger documentation for reference. However, an increase in point-of-care testing will need to go hand-in-hand with instructions made with final users in mind. Our conversations with members of the industry suggest that clashing requirements of regulation and final users are acknowledged, but time constraints in manufacturing and approval processes mean that meeting the regulations is prioritised over clear patient- or user-facing communication. Collaborative work between graphic communication designers and designers of medical devices may be a way forward to align products to the needs of regulators and patients.