Familiar over novel
Users bring habits from every other site and app they use. On a screen someone is reading while stressed or unwell, don't ask them to relearn a pattern they already know.
Adapted from Jakob's Law — lawsofux.com
Healthcare UX Principles
UX laws, applied to health interfaces.
General UX laws and healthcare-specific design principles, each with a real application - dosing screens, RPM alerts, clinician dashboards, consent flows.
Fewer choices, faster decisions
The time it takes to decide grows with the number and complexity of options. At a dosing or scheduling screen, show fewer choices at once, not more.
Adapted from Hick's Law — lawsofux.com
Chunk what you show at once
Working memory holds about seven items before it drops something. A multi-patient dashboard should group and chunk, not list everything flat.
Adapted from Miller's Law — lawsofux.com
Make the critical action easy to hit
The time to reach a target depends on its size and distance. A confirm-dose or call-for-help button needs to be large and close, especially for a hand that isn't steady.
Adapted from Fitts's Law — lawsofux.com
Reduce cognitive load first
Lowering the mental effort needed to use an interface is the single strongest lever in health UX — stronger than any individual pattern choice.
Cognitive Load — lawsofux.com
Answer within 400ms
Productivity holds up when a system responds fast enough that the user never waits on it. An RPM threshold alert that lags erodes trust in the reading itself.
Adapted from the Doherty Threshold — lawsofux.com
Accept messy input, send clean output
Be liberal in what a form accepts and strict in what it shows back. A date-of-birth or dosage field should tolerate the format a tired user actually types.
Adapted from Postel's Law — lawsofux.com
The last screen is what's remembered
People judge an experience by its most intense moment and how it ends, not its average. A consent flow or booking should end clearly and calmly, not trail off.
Adapted from the Peak-End Rule — lawsofux.com
Accessibility is the floor, not the goal
WCAG 2.2 AA is the minimum a health interface has to clear, not an aspiration. Status can't be colour alone; everything needs a keyboard path.
WCAG 2.2 AA
Plain language saves attention
A 2003 review estimated that 40–80% of what practitioners tell patients is forgotten straight away - a broad estimate, not a precise measurement. Write for someone who is unwell or scared, not for a textbook.
Kessels, J R Soc Med, 2003
Clinical and patient interfaces speak different languages
A clinician scanning ten patients needs density and speed. A patient looking at the same data needs interpretation, not a raw chart. Same numbers, two different designs.
Clinical vs patient interface design
Design for the edge, not the average
Low vision, tremor, low digital confidence, a second language — these aren't edge cases in health, they're a large share of who is using the screen. Design for them directly.
Inclusive / vulnerable-user design