Medication reminders and the missed dose

Prompting a person to take a medicine at the right time, recording whether they did, and handling the moment a dose is missed with a response that is proportionate to the medicine rather than a generic nag. The missed dose is the part that matters: it is where a reminder either helps, or becomes noise the person learns to dismiss.

Non-adherence is common and consequential: the World Health Organization's 2003 review of adherence to long-term therapies put average adherence among people with chronic conditions in developed countries at around 50 per cent. A reminder app cannot fix the reasons behind that (cost, side effects, complexity, disbelief) but it can remove forgetting from the list, and it can tell someone else when forgetting becomes a pattern.

Whether it does either depends on the design of the missed dose: what the app says, when, and to whom.

The right response to a missed dose depends on the drug. For some medicines the instruction is to take it as soon as remembered; for others it is to skip it and never to double up; for a few (anticoagulants, insulin, immunosuppressants) a missed dose is a clinical event a prescriber may want to know about. A generic “you missed your 8am dose” is therefore safe only if it makes no recommendation. A product that goes further needs the specific instruction for that medicine, from a source it can name, and a way to defer to the pharmacist or prescriber where the answer is not general.

Sharing adherence with a caregiver, which Medisafe describes through Medfriend, is useful and sensitive in equal measure: the person taking the medicine should control who is told and what. And because a reminder schedule is a de facto medication record, changes to it (a dose stopped, a time moved) deserve the same care as a prescription change.

A reminder that cannot be perceived is not a reminder. Notifications need more than one channel (sound, vibration and a persistent visual state) and a person should be able to set their own repeat and snooze intervals rather than accept a fixed one (WCAG 2.2 Timing Adjustable, 2.2.1).

Taking a dose is often done one-handed, in poor light, by someone whose dexterity or vision is affected by the condition being treated. The “taken” and “skip” controls need to be large (Target Size Minimum, 2.5.8), distinguishable by more than colour (Use of Color, 1.4.1) and forgiving of a wrong tap. Medicine names are long and easily confused; where the app shows several, the difference between them should be legible at a glance and read out correctly by a screen reader.

Two products in the library describe reminders on their public pages, and both position the reminder as a behaviour tool rather than a clock. Medisafe says its reminders “respond to patient behavior” and adapt to individual routines, and describes Medfriend, which shares adherence updates with family members and caregivers the person chooses. Huma describes a Medications widget that tracks dose, schedule and adherence, and a Reminders widget, as building blocks of the monitoring apps it configures for health systems.

Neither public page describes what the app says when a dose is missed: the instruction, if any, and whether it differs by medicine. That is the part of the pattern with the most clinical weight and the least public documentation, and the library will add examples of the missed-dose response itself as products document it.