A Canadian study published today in the Annals of Internal Medicine suggests that about one third of new prescriptions (written by primary care physicians) are never filled. Over 15,000 patients were followed from 2006 to 2009. Prescription and patient characteristics were analyzed, though patients were not directly interviewed about their rationale for not filling their prescriptions.
In short, patients were less likely to fill a prescription if the treatment was expensive, but certain types of drug indications had consistently higher non-fill rates:
- Headache (51% not filled)
- Ischemic heart disease (51.3% not filled)
- Thyroid agents (49.4% not filled)
- Depression (36.8% not filled)
Overall, hormonal (especially Synthroid), ENT (especially Flonase), skin, and cardiovascular drugs (especially statins) had the highest non-fill rates.
As far as those prescriptions more likely to be filled, antibiotics (especially for urinary tract infections) ranked number one.
Trends towards prescription compliance were seen among older, healthier patients, and those who were switching medications within a class rather than starting an entirely new drug. Patients who received prescriptions from a doctor that they visited regularly (rather than a new provider) were also more likely to fill their prescriptions.
This study was not designed to elucidate the exact rationale behind prescription non-adherence, but I am willing to speculate about it. In my experience, patients are less likely to fill a prescription if a reasonable over-the-counter alternative is available (think headache or allergy relief). I also suspect that they are less likely to fill a prescription if they believe it won’t help them (skin cream) or isn’t treating a palpable symptom (statin therapy for dyslipidemia). Finally, patients are probably nervous about starting a medicine that could effect their metabolism or cognition (thyroid medication or anti-depressant) without a full explanation of the possible benefits and side effects.
I was surprised to see how compliant patients seem to be with antibiotic agents (at least, filling the initial prescriptions). Given the increasing rates of antibiotic resistance, this reinforces the need to limit prescriptions to those agents truly indicated, and to analyze bacterial sensitivities during the treatment process to optimize medical management.
My take home message from this study is that providers need to do a better job of explaining the reasoning behind new prescriptions (their necessity, consequences of non-compliance, and risk/benefit profiles) and reviewing the overall cost to the patient. If a cheaper, effective alternative is available (whether OTC or generic), we should consider prescribing it. Providers can likely improve medication compliance rates with a little patient education and price consciousness. Extra time should be spent with patients at higher risk for non-compliance due to their personal situation (age, degree of illness, income level) or if a specific drug with lower compliance rates is being introduced (Synthroid, statins, etc.) Regular follow up (especially with the same prescriber) to ensure that prescriptions are filled and taken as directed is also important.