Medication Adherence in Australia: Why 51% of Us Struggle

Roughly half of people living with a chronic condition in Australia do not take their medication exactly as prescribed. That's not a fringe problem — it's the norm for a huge share of long-term medication users, and it carries a real cost to both individual health outcomes and the health system. This isn't unique to Australia; non-adherence is recognised internationally as one of the largest, most under-addressed gaps in chronic disease management — but the local numbers are worth understanding on their own terms.

What the research shows

• An estimated 50% of Australians living with a chronic disease do not adhere to their prescribed medication regimen (Pharmacy Guild of Australia).
• For three common, prevalent conditions alone — hypertension, dyslipidaemia and depression — medication non-adherence was estimated to cost the Australian health system $10.4 billion per year, equivalent to around $517 per adult (Patient Preference and Adherence, 2019). This figure covers only those three conditions — the true total across all chronic disease is higher.
• A pharmacist-led adherence intervention reduced non-adherence costs by approximately $95 per adult in the study group, pointing to real, measurable savings when adherence support is in place.
• Around 5.6% of Australians delay or skip GP-prescribed medicines for financial reasons in a given year, rising to roughly 9.5% among people with poor or fair self-reported health — cost-related non-adherence is concentrated among people who are already managing the most complex health needs.

Why adherence breaks down

Non-adherence is rarely a single cause, and treating it as a simple forgetfulness problem misses most of what the research describes. The contributing factors generally fall into a few overlapping categories:

• Cost. Even with PBS subsidies, the cumulative cost of multiple regular medications adds up — and is the documented reason a meaningful share of Australians delay or skip doses.
• Regimen complexity. The more medications, dosing times, and special instructions (with food, on an empty stomach, twice daily) a person has to track, the more opportunities there are for a dose to be missed.
• Side effects. When a medication causes an unpleasant side effect, stopping or skipping doses without telling a prescriber is common — and is one of the most preventable causes of non-adherence, since dose or medication adjustments are often available.
• Forgetting. Especially for medications without an immediate, noticeable effect (blood pressure medication is a classic example), it's easy for a dose to slip from a routine that isn't reinforced by any felt symptom.
• Health literacy and belief. Some non-adherence stems from uncertainty about why a medication matters, or a personal belief that it's no longer needed — both of which respond well to a conversation with a pharmacist or doctor, more than a reminder alone.

Who is most affected

Non-adherence isn't evenly distributed. It's more common among people managing multiple chronic conditions at once (polypharmacy), among people with lower self-reported health status, and among people facing cost-related barriers to care. Adherence to cardiovascular medication, in particular, tends to drop sharply in the first year after starting a new prescription — the period where habit formation matters most and where reminder-based support has the clearest opportunity to help.

What's been shown to help

Pharmacist-led medication reviews, simplified dosing schedules, and consistent reminder systems are among the interventions associated with measurable improvements in adherence. Digital tools that combine reminders with adherence tracking can support this by making it easier to spot a slipping pattern early, rather than only after a missed appointment or a health setback — which is the gap apps like PillWise are designed to close. Read more in our guide to reminder strategies that actually work, and on the interaction-risk side of complex regimens in our drug interactions guide.

Frequently asked questions

What percentage of Australians don't take their medication as prescribed?

An estimated 50% of Australians living with a chronic disease do not adhere to their prescribed medication regimen, according to the Pharmacy Guild of Australia.

How much does medication non-adherence cost Australia?

For three common conditions alone — hypertension, dyslipidaemia and depression — medication non-adherence was estimated to cost the Australian health system $10.4 billion per year, around $517 per adult, according to a 2019 study in Patient Preference and Adherence. The true total across all chronic disease is higher.

Why don't people take their medication as prescribed?

Cost, complex multi-drug regimens, side effects, and simply forgetting amid a busy routine are the most commonly cited reasons. Around 5.6% of Australians delay or skip GP-prescribed medicines for financial reasons in a given year.