Mobile “Thumb” Test: Can You Do the Top 5 Tasks One‑Handed?

On a busy morning, most patients will visit your GP or healthcare site on a phone, with one hand, often under stress. If they cannot complete the top 5 tasks with their thumb, in three taps or fewer, your site is failing both patients and accessibility standards.

This article explains how to use a simple mobile “thumb” test to assess your site, and what to change if it fails – with a focus on UK GP practices, NHS expectations, and WCAG compliance.

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What Is the Mobile “Thumb” Test?

The mobile “thumb” test is a practical way to judge whether your website truly works on a smartphone.

On a typical smartphone, using one hand and without zooming, can a patient:

• Tap big buttons and links without mis‑taps Read text easily
• Find “Directions” to the practice
• See an emergency or urgent notice
• Reach Prescriptions, Appointments, Test Results in 3 taps or fewer

If not, your site is very likely:

• Using an old or non‑responsive theme
• Failing mobile and accessibility best practice
• Increasing risk of complaints, drop‑offs, and potential non‑compliance with accessibility regulations

For UK practices, this is more than design preference – it’s core to NHS Digital guidance, the Public Sector Bodies (Websites and Mobile Applications) Accessibility Regulations 2018, the Equality Act 2010, and WCAG 2.1 AA.

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Why This Matters in UK Healthcare

Most healthcare journeys now start on mobile. Patients use phones to:

• Register with a GP
• Order repeat prescriptions
• Book or manage appointments
• Read test results
• Find urgent contact details or directions

For NHS and GP websites, poor mobile design can:

• Disproportionately disadvantage older adults, people with visual or motor impairments, and those with low digital literacy
• Lead to accessibility complaints and enforcement action under public sector accessibility regulations
• Increase phone calls and front‑desk pressure, because people give up online

Designing for thumbs is therefore part patient safety, part accessibility, and part operational efficiency.

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Minimum Tap Target Sizes: Make It Easy to Hit, Even Under Stress

On mobile, patients tap with fingers, not a mouse pointer. That means tap targets must be large, spaced, and forgiving.

Recommended tap target sizes

Industry and accessibility guidance typically recommends:

• At least 44 × 44 CSS pixels (around 9 mm × 9 mm) for buttons, links, and controls
• Enough spacing so users don’t accidentally tap the wrong thing
• Clear visual feedback (colour change, outline) when an element is tapped

For GP practices, prioritise large tap targets for:

Primary tasks

• Appointments
• Repeat prescriptions
• Test results
• Online consultation / triage tools
• Critical contact controls
• Call the practice
• NHS 111
• Directions / Map
• Emergency and out‑of‑hours information

Practical actions

• Ask your web provider to audit tap targets against WCAG 2.1 AA, especially:
  • Header menu items
  • Footer links
  • Form buttons
  • Patient platform links (e.g. NHS App, Patient Access)
  • Replace tiny text links (“click here”) with full‑width buttons
  • Avoid “button farms” with many small options in a row – group and prioritise instead

Case example

A Midlands GP practice reduced home‑page links and converted the top 4 patient tasks into large buttons (Appointments, Prescriptions, Test Results, Contact Us). After launch, staff noted a drop in “I can’t find…” calls and more successful online prescription requests from older patients.

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Sticky Essentials: Keep Critical Phone & Task Buttons Within Thumb Reach

On a mobile screen, the most valuable real estate is where the thumb naturally rests – usually the lower third of the screen. Critical actions should live there, and stay there.

What are “sticky essentials”?

“Sticky” elements are interface components that stay visible as the user scrolls, such as a fixed bottom bar.

For GP sites, a mobile‑friendly sticky bar might include:

• Call the practice Appointments
• Prescriptions Results / Online services
• Menu or More

This approach supports:

• One‑handed use, especially for people with limited reach or dexterity

• Faster access for patients in pain, distress, or urgency

• Compliance with WCAG principles of operability and low physical effort Feature: Sticky essentials

• Place key actions in a bottom sticky bar on mobile:

  • Phone
  • Appointments
  • Prescriptions
  • Results / Online services
  • Ensure:
    • Buttons are large and labelled with clear text
    • Icons are supported by text, not used alone
    • Colour contrast meets WCAG (e.g. no pale grey text on white)
    • They are accessible via keyboard and screen reader Common pitfalls

• Sticky “cookie banners” or chat widgets that cover key controls

• Tiny floating icons that are hard to tap and not screen‑reader friendly

• Only having key actions in a hidden hamburger menu

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Make “Directions” and Location One Tap

A patient trying to find your building while standing in the rain does not want to hunt through menus.

On mobile, Directions should be one tap from the home screen, ideally via:

• A clearly labelled “Directions” or “Find us” button
• Positioned above the fold (visible without scrolling)
• With a large tap area that opens:
  • A map with your location marked
  • A “View in Maps” / “Open in Google Maps / Apple Maps” style link

Feature: Directions

• One‑tap access from:

  • Home page
  • Contact page
  • Ensure:
    • Address is plain text, not embedded in an image
    • Map is accessible (alternative text for embedded maps, clear labels)
    • A route planning link is available
    • Parking, disabled access, and public transport details are easy to reach Patient scenario

• A visually impaired patient uses a screen reader and is running late for an appointment.

• On a good site:

  • A “Directions” button appears near the top.
  • The button label is read correctly by the screen reader.
  • One tap opens their mapping app.
  • On a poor site:
    • Directions sit inside a PDF leaflet or buried under “About”.
    • The screen reader cannot easily find or activate it.
    • The patient arrives late or misses the appointment.

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Emergency Notices and Urgent Information: Always Visible, Always Clear

Patients should never have to hunt for urgent or emergency guidance.

A mobile‑friendly, accessible GP site should:

• Display urgent messages and emergency guidance clearly at the top:
  • “Call 999 in a life‑threatening emergency”
  • “Use NHS 111 for urgent advice when the surgery is closed”
  • Temporary closures, phone outages, or service changes
  • Use:
    • Clear heading text
    • High contrast colours
    • No reliance on colour alone (important for colour‑blind users)

Practical actions

• Use a simple alert banner at the top of the page, not a rotating carousel
• Ensure the alert:
  • Works well on mobile
  • Is fully readable without zoom
  • Can be dismissed if it’s not critical, but is obvious if it is
  • Provide alternative options for people who cannot use the phone:
    • Online consultation
    • Relay or text alternatives where available

This supports both patient safety and legal duties to make services accessible.

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Key Tasks in Three Taps or Fewer

From the patient’s perspective, being able to complete core tasks quickly is the whole point of your site.

The three‑tap rule on mobile is:

• From home page, a patient should reach:

  • Prescriptions Appointments

• Results / Online services In no more than three taps, without needing to zoom or guess. Example of a good three‑tap flow

• Tap 1: Open practice website on mobile

• Tap 2: Tap “Appointments” button in the sticky bar or main hero area

• Tap 3: Tap “Book online via NHS App” or “Book via online portal”

What to avoid

• Long “Services A–Z” lists where key tasks are hidden amongst clinical content

• Multiple signposting layers (Home → Patients → Online services → Appointments → Book)

• Buttons that link to a generic portal with no explanation of what to do next Checklist: can patients complete top tasks quickly?

• Review your site on a standard smartphone:

How many taps to:

• Request a repeat prescription?
  • Book or cancel an appointment?
  • View test results?
• Can this be reduced?
• Ensure task labels are action‑oriented:
  • “Order repeat prescription” instead of “Medication”
  • “Book or manage appointments” instead of “Services”

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Avoid Carousels and Tiny Menus

Many older GP themes rely on image carousels, tiny top‑nav menus and small text links. On mobile, these are among the worst offenders for poor usability and accessibility.

Why carousels are a problem

Carousels (sliders) cause issues on mobile because:

• They often use small tap targets for navigation arrows or dots
• Content changes automatically, which can be problematic for:
  • People with cognitive impairments
  • Screen reader users
  • Important messages may be missed if they are on “slide 3”
  • They can interfere with keyboard navigation and screen‑reader focus

For NHS and GP sites, it is usually better to:

• Replace carousels with static panels or simple stacked cards
• Prioritise one clear message or primary task area at the top

Tiny menus and hamburger overload

A single small “hamburger” icon in the top corner is:

• Harder to reach with the thumb
• Easy to miss for users with low digital skills
• Problematic when the menu itself is crowded and deep

Practical improvements

• Use clear text buttons for the top 3–5 tasks directly on the home screen
• Ensure the main navigation:
  • Uses large, spaced items
  • Is logically grouped (e.g. “Online services”, “Practice information”)
  • Avoids long, nested sub‑menus on mobile
  • If you keep a hamburger menu:
    • Make the icon and label large
    • Add a text label “Menu”
    • Ensure the menu opens with focus in a way that works with screen readers

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The Patient POV vs “Looks Nice on Desktop”

A common issue in UK healthcare is that websites are commissioned and approved based on desktop designs, yet most real‑world use is on phones.

From the patient’s point of view:

• They often:
  • Are using the site on the move
  • Have limited time, low bandwidth, or poor signal
  • May be in pain, anxious, or caring for someone else
  • May have visual, cognitive, or motor impairments
  • They care about:
    • “How do I do X right now?”
    • “Where is the surgery?”
    • “What do I do if it’s urgent?”

From a “looks nice on desktop” perspective:

• Designers may prioritise:
  • Large hero images
  • Multiple promotional banners
  • Complex layouts that don’t scale down well
  • Decorative elements instead of functional ones

This gap leads to beautiful desktop sites that are frustrating on phones. Patient‑centred design principles for GP sites

Function over decoration

• Prioritise clarity, speed, and legibility over imagery
• Plain language Use headings like:
• “Book or manage appointments”
  • “Order repeat prescription”
  • “Get your test results”
• Real‑world testing Ask patients:
• “Can you do these 5 tasks with one hand on your phone?”

Test with:

• Older patients
  • People with long‑term conditions
  • Carers Simple case study

A London practice migrated from an old, image‑heavy theme to a task‑focused design:

• Carousels removed
• Top of the mobile home page now has:
  • “Appointments”, “Prescriptions”, “Results”, “Contact”, “Directions”
  • Sticky bottom bar repeats key actions

They reported:

• Fewer “How do I request my prescription?” calls
• Better feedback from the PPG, particularly from older patients
• Easier compliance with accessibility statements and audits

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Aligning With WCAG and UK Digital Accessibility Regulations

For NHS and GP sites, mobile “thumb” friendliness supports compliance with:

Public Sector Bodies (Websites and Mobile Applications) Accessibility Regulations 2018

• Equality Act 2010
• NHS commitments to digital inclusion and accessible information

Designing so that users can comfortably operate your site with one hand, without fine motor control, aligns with WCAG principles:

• Perceivable
• Text large enough and high contrast
• Content readable without zooming horizontally Operable
• Large tap targets
• No complex gestures required
• No reliance on time‑limited carousels
• Understandable
• Clear labels and navigation
• Consistent layouts and naming Robust
• Works with assistive technologies such as screen readers and magnifiers

Although WCAG does not only apply to mobile, implementing good thumb‑friendly practices helps meet many criteria, especially around target size, pointer gestures, and input modalities.

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How to Run a Quick Thumb Audit of Your Practice Website

You can perform a basic, practical test in under 15 minutes.

Step 1: Use a real phone

• Avoid only testing in browser dev tools
• Use:
  • iPhone and an Android device if possible
  • A standard size (not just large Pro/Max models)

Step 2: Try the top 5 tasks one‑handed

Without zooming, using your thumb only:

• Can you:
  • Tap main buttons without mis‑tapping?
  • Read headings and key text comfortably? Find and use:
• Directions
  • Emergency or urgent advice
  • Prescriptions
  • Appointments
  • Results / Online services In 3 taps or fewer?

Make notes of where you struggle. Step 3: Check accessibility basics

• Are link and button labels clear and descriptive?
• Does text have good contrast and reasonable size?
• Are there carousels, auto‑rotating banners, or pop‑ups getting in the way?
• Is any key information only present in:
  • Images without text alternatives?
  • PDFs that are hard to read on mobile?

Step 4: Involve patients and staff

Ask a small group:

• Patients (via PPG, clinic waiting room, or a small test group)
• Reception or care navigators (they know what patients struggle with)

Observe them using their own phones to complete key tasks. The goal is not perfection, but pattern recognition: where do they get stuck or frustrated?

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Key Takeaways

• If patients cannot complete the top 5 tasks with one hand in three taps, your site likely has outdated mobile patterns and accessibility risks.
• Minimum tap target sizes, clear spacing, and high contrast are essential for:
  • Patients with limited dexterity
  • People using the site under stress or in a hurry
  • Sticky essentials (phone and key tasks) anchored near the thumb greatly improve one‑handed use and patient experience.
  • “Directions” and emergency information must be one tap away, not buried in PDFs or long menus.
  • Avoid carousels and tiny menus that work on desktop but break real‑world mobile use.
  • Designing for the patient’s reality, not for desktop aesthetics, reduces call volumes, improves satisfaction, and supports compliance with WCAG and UK accessibility regulations.

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Conclusion and Next Steps

To move from “looks nice on desktop” to genuinely patient‑friendly and compliant, treat the mobile “thumb” test as a core requirement, not an optional extra. Immediate next steps

• Run a 15‑minute thumb audit on your current site

• List the top 5 patient tasks and count taps on mobile

• Identify:

  • Tiny tap targets
  • Hidden directions and emergency information
  • Carousels and complex menus Medium‑term actions

• Work with your website supplier to:

  • Implement large, thumb‑friendly buttons for key tasks
  • Add a mobile sticky bar with phone and core services
  • Make Directions and emergency notice areas prominent and tap‑friendly
  • Remove or replace carousels with static, accessible panels
  • Ensure your site is being tested against WCAG 2.1 AA and UK public sector accessibility regulations, including on mobile devices.

By designing for one‑handed, real‑life use, your GP or healthcare website will not only pass a “thumb” test – it will become a safer, more inclusive, and more efficient front door to your services.