Medication adherence is how consistently you take your medication exactly as prescribed: the right dose, at the right times, and for the full length of time your prescriber intended. It is usually expressed as a percentage, the share of your scheduled doses you actually took over a period.

For example, if you were scheduled for 60 doses in a month and took 54 of them, your adherence is 90 percent.

This is general information, not medical advice.

How is medication adherence measured?

Adherence is the number of doses taken divided by the number of doses scheduled, over a set period, turned into a percentage. As-needed (PRN) medications are normally excluded, because they have no fixed schedule to measure against.

A common reference point clinicians use is 80 percent or higher, often treated as the rough line for a regimen working as intended, though the right target depends on your condition and your prescriber.

Adherence vs compliance vs persistence

These related terms are easy to confuse:

  • Adherence is taking medication as agreed with your prescriber. The word emphasises a shared plan rather than just following orders.
  • Compliance is an older term meaning the same thing, but it implies the patient simply obeys instructions. Adherence is now preferred.
  • Persistence is how long you keep taking a medication before stopping, measured in time rather than as a percentage.

Why does medication adherence matter?

Medications can only work if they reach a consistent level in your body, which depends on taking them as prescribed. Low adherence is linked to worse outcomes and avoidable complications for many conditions. For a fuller explanation, see why medication adherence matters.

How can I improve my adherence?

The most effective steps are practical: reminders with follow-ups, attaching each dose to an existing daily habit, using dose windows so a slightly late dose still counts, and tracking your patterns so you can see where you slip and fix it.

Frequently asked questions

What is a good medication adherence rate?

For most chronic medications, 80 percent or higher is the common reference point for a regimen working as intended, but the right target depends on your specific condition and what your prescriber advises.

Is medication adherence the same as compliance?

They mean roughly the same thing, but adherence is the preferred modern term because it reflects a shared plan between patient and prescriber, rather than simply obeying instructions.

Are as-needed medications counted in adherence?

No. As-needed (PRN) medications have no fixed schedule, so they are normally excluded from an adherence rate, which only measures scheduled doses.

Cadence is a free medication reminder app for iPhone that tracks your adherence automatically. It is not medical software and does not provide medical advice. Cadence Pro is $9.99 as a one-time purchase.