We briefly spoke about Primary non-adherence (PNA) as a subcategory from our previous blog “4 types of medication non-adherence”. For this blog, we will explore the formal definition of PNA, what factors contribute to PNA, and what we can do to reduce the likelihood of PNA from occurring.

What is Primary non-adherence?

Primary non-adherence is defined as a failure to start treatment because the prescribed medication is not picked up or received. In contrast, Secondary non-adherence (SNA) is defined as a failure to take medication as prescribed, a failure to refill the prescription or to discontinues the treatment. It’s important to differentiate and monitor these two types to better understand why medication therapy is not effective.

Roughly, about 1 in 3 patients are PNA1, but other studies suggest the numbers can vary depending on the medication class. 2,3  This is a serious issue for patient outcomes since they will not reap the benefits of treatment if they don’t even start. To quote the former US Surgeon General C. Everett Coop, “Drugs don’t work in patients who don’t take them.” 

What’s stopping them from picking up their prescription?

To most people, it seems trivial to visit a pharmacy to pick up a medication that is essential for our survival or improve our quality of life. However, the current literature suggests otherwise because of personal and environmental factors that make this process difficult. They are categorized into 5 contributing factors: patient, medication, health care provider, health care system, and socioeconomic factors4.

  • Patient factors. Patient profiles, such as age, sex, ethnicity, and health literacy, can affect the likelihood of the patient showing PNA. 
  • Medication factors. The number of medications, types of drugs, how to handle the medication, and the overall cost have shown to influence the likelihood of PNA. 
  • Health care provider factors. The patient-physician relationship and the patient’s perception of a physician’s qualifications have shown to influence the likelihood of PNA. 
  • Health care system factors. The types of technology, such as e-prescription, and hospital or clinic services, such as translators, have shown to influence the likelihood of PNA. 
  • Socioeconomic factors. Where the patient lives, access to pharmacies and transportation,  have shown to influence the likelihood of PNA. 

How can we reduce the likelihood of Primary non-adherence? 

Although PNAs have not been studied as extensively as SNAs, the literature has provided some studies to influence a positive outcome. One key relationship is between the patient and the health care provider. It’s been found that patient and health care provider factors play a key role in influencing patient decisions to start treatment.4 These positive patient-physician relationships can increase the likelihood to pick up medication by up to 33%.5

The literature has also found that patient health literacy, defined as ‘the degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions’,6 and how the physician educates the patient can improve medication adherence. 5

The development of e-prescription technologies has shown an improvement in medication adherence. Sending e-prescriptions that were transmitted directly to the pharmacy reduces the likelihood of PNA from occurring by up to 10% compared to giving the patient a printed copy. 7 

Lastly, interventions for polypharmacy has some positive outcomes for primary non-adherence.8  These interventions improved patient outcomes and decrease costs, especially for seniors. One such example of these interventions is drug reminder packaging.9 



1 Storm, A., Andersen, S. E., Benfeldt, E., & Serup, J. (2008, May 7). One in 3 prescriptions are never redeemed: Primary nonadherence in an outpatient clinic. Retrieved March 2020, from https://www.sciencedirect.com/science/article/abs/pii/S0190962208004234

2 Tamblyn, R., Eguale, T., Huang, A., Winslade, N., & Doran, P. (2014). The Incidence and Determinants of Primary Nonadherence With Prescribed Medication in Primary Care. Annals of Internal Medicine, 160(7), 441. doi: 10.7326/m13-1705 

3 Stockman, J. (2012). The Epidemiology of Prescriptions Abandoned at the Pharmacy. Yearbook of Pediatrics, 2012, 545–547. doi: 10.1016/j.yped.2011.06.015

4 Lee, S.-Q., Raamkumar, A. S., Li, J., Cao, Y., Witedwittayanusat, K., Chen, L., & Theng, Y.-L. (2018). Reasons for Primary Medication Nonadherence: A Systematic Review and Metric Analysis. Journal of Managed Care & Specialty Pharmacy, 24(8), 778–794. doi: 10.18553/jmcp.2018.24.8.778

5 Ngoh, L. N. (2009). Health literacy: A barrier to pharmacist–patient communication and medication adherence. Journal of the American Pharmacists Association, 49(5). doi: 10.1331/japha.2009.07075

6 Kerse, N., Buetow, S., Mainous, A. G., Young, G., Coster, G., & Arroll, B. (2004). Physician-patient relationship and medication compliance: a primary care investigation. Retrieved March 2020, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1466710/

7 Fischer, M. A., Choudhry, N. K., Brill, G., Avorn, J., Schneeweiss, S., Hutchins, D., … Shrank, W. H. (2011). Trouble Getting Started: Predictors of Primary Medication Nonadherence. The American Journal of Medicine, 124(11). doi: 10.1016/j.amjmed.2011.05.028

8 Kojima G, Bell C, Tamura B, et al. Reducing cost by reducing polypharmacy: the polypharmacy outcomes project. J Am Med Dir Assoc. 2012;13(9):818.e811–815.

9 Ascione, F. J., & Shimp, L. A. (1984). The Effectiveness of Four Education Strategies in the Elderly. Drug Intelligence & Clinical Pharmacy, 18(11), 926–931. doi: 10.1177/106002808401801121