Top reasons patients don’t adhere to treatment

By Linda M. Richmond
Published April 9, 2021

Key Takeaways

A physician’s treatment only works as well as a patient follows it. While this statement may seem obvious, medication nonadherence is a major issue in the United States. According to government data, about one in five new prescriptions are never filled, and among those filled, half are not taken according to doctors’ orders for timing, dosage, frequency, and duration.

Consider these examples:

  • Statin medications reduce cardiovascular events for those at risk, but many patients are not taking them. A study in Medical Decision Making found that only half of patients (48%) prescribed statins are still taking their prescribed dose after one year, and only a quarter (27%) are adherent after 10 years. 

  • One in four pregnant women with asthma who are prescribed inhaled corticosteroids doesn’t use them—this is despite potentially serious consequences for mother and baby, according to an analysis in the Journal of Allergy and Clinical Immunology in Practice

  • Among patients with major psychiatric disorders (bipolar, schizophrenia, or depressive disorder), half don’t take their psychotropic medications as prescribed, despite the risk of relapse, according to a meta-analysis in Systemic Reviews.

Poor medication adherence can result in faulty therapeutic decisions, such as physician escalation of therapies when clinical metrics are not achieved, according to the CDC. It also results in greater hospitalization and emergency department rates, higher mortality, and worse patient outcomes.

Recent research sheds light on the top reasons patients don’t take their meds.

The fear factor

Fear is listed first among the top reasons patients don’t take their medications, according to the AMA, and recent literature seems to bear this out. A new study in Preventive Medicine Reports, of patients who don’t fill their statin prescription, reveals that more than half (56%) are strongly or somewhat worried about the possibility of statin dependence or addiction. Furthermore, a majority of participants preferred trying natural remedies or dietary supplements prior to beginning a statin regimen (72%-77%).

The authors recommended addressing patient attitudes, beliefs, and willingness to start medication, and offering educational materials at the initial appointment to manage a chronic condition.

Side effects: Real, imagined, and ‘nocebo’

According to the AMA, patients' fears of potential side effects based on their own experience or that of friends or family members play a role in medication nonadherence.

While some drugs have worse potential side effects than others, how the physician talks to the patient also plays a role in whether or not they experience side effects. Why is that? Research shows that patients who receive highly detailed disclosures of possible side effects may experience more of them. This has been dubbed the “nocebo,” or the opposite of the placebo response.

For example, in a study of aspirin for the treatment of unstable angina, one group of patients received an outline of possible gastrointestinal (GI) side effects whereas the other did not. Patients who received the side effect list were a whopping six times more likely to withdraw from treatment due to minor subjective GI symptoms, compared to those who didn’t receive the list, according to a study in The American Journal of Bioethics.

Minimizing the nocebo effect involves “taking into account the possible side effects, the person being treated, and the disease involved to tailor the information provided about medication side effects to provide the most transparency with the least potential harm,” the authors wrote. 

High costs

It’s no surprise that cost is a top driver of patient nonadherence, with the US list price of prescription drugs soaring 33% since 2014, according to a recent report by drug discounter GoodRx. In fact, this rise outpaces the average growth in hourly earnings by more than 50% during the same time period. Compounding this issue is the fact that more than one in 10 Americans were uninsured as of 2019. Experts say this number has likely grown since the start of the pandemic.

It’s not always uninsured or marginally insured patients who struggle the most with affording their medications: Despite coverage by a Medicare Part D drug plan, nearly half of participants in one new study (49%) had cost-related nonadherence (CRN). Another 14% of participants reported “persistent” CRN, lasting 9 months or longer, according to the report in JAMA Network. One reason? Medicare drug insurance programs require high out-of-pocket payments for nonpreferred or nonformulary drugs. 

Unfortunately, patients who cannot afford their medications may be reluctant to self-identify. “To overcome this, check that the drug you’re prescribing is on the patient’s insurance formulary. Selecting and prescribing a medication known to be on the discount list can decrease the cost regardless of insurance,” notes the AMA. 

Complexity and confusion

Having multiple prescriptions to fill and complex dosing regimens is another driver of medication noncompliance, particularly among the elderly. One study, published in BMC Geriatrics, found that more than half (56%) of patients could not identify the purpose of at least one of their medications. Only two-thirds knew their correct dosage regimen.  

Taking the time to assess patients’ knowledge of their disease and understanding of their medication regimen can go a long way. Participants with a higher level of knowledge about their medications’ therapeutic purpose and dosage regimen were seven times more likely to adhere to their prescribed frequency and dose, according to the study. Researchers also found that those with a less complex regimen were twice as likely to adhere to their medication regimen.


Depression is a known risk factor for medication adherence. In fact, one meta-analysis in JAMA Network involving 30 years of research data found that depressed patients are three times more likely to have poor medication adherence and poor health behavior.  

“For patients who are beginning their courses of treatment for chronic disease, screening for depression might prove to be a useful identifier of possible future noncompliance and might suggest closer monitoring and assistance to achieve adherence,” the authors wrote. Researchers found no link, however, between patient anxiety and medication nonadherence.

Bottom line

Physicians play a key role when it comes to patient adherence. Taking the time to ask questions about patient concerns and ensuring they understand the reasons for taking medications can go a long way.

Dr. Angela DeMichele, professor of medicine and epidemiology, at the University of Pennsylvania, shared her thoughts on patient adherence in an exclusive interview with MDlinx. Learn more about how you can help your patients overcome this hurdle to treatment here.  

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