How Does Pharmacy Synchronization Help Endocrine Therapy Adherence?

A new study published in Cancer shows that synchronization of medication refills can increase adherence to endocrine therapy for breast cancer, suggesting a relatively simple way to improve outcomes for a large number of patients.

“As more oral oncologic agents have become available, it has become clear that many patients skip pills or stop taking them before the planned course has been completed,” wrote study authors led by Joan M. Neuner, MD, MPH, of the Medical College of Wisconsin in Milwaukee. “One-third to one-half of patients prescribed adjuvant endocrine therapy (AET) with tamoxifen or an aromatase inhibitor either discontinue early or skip a substantial number of pills.”

One possible explanation for this is poor synchronization of medication fills, meaning that patients are required to pick up various prescriptions from a pharmacy on multiple days. The researchers examined whether such synchronization may be associated with AET adherence in a cohort of 3,212 women with breast cancer identified using the Surveillance, Epidemiology, and End Result-Medicare claims-linked cancer registry.

Synchronization was calculated based on a 3-month prescription record dating from the first endocrine therapy fill. It was based on the number of pharmacy visits and the number of unique filled medications. The group was stratified based on the number of unique medications (2-4 medications, 5-8, and more than 8); the mean number of medications was seven, and the mean number of pharmacy visits in the 3-month window was 8.6.

There were four medication-adjusted synchronization quartiles. Compared to the lowest quartile (meaning, that with the poorest synchronization of medication refills), the third quartile and the highest quartile (best synchronization) were significantly more likely to be adherent to AET. For the third quartile, the odds ratio was 1.30 (99% CI, 1.05–1.60); for the fourth quartile, the OR was 1.49 (99% CI, 1.19–1.87).

Other factors associated with adherence included race other than white or black, and the presence of one or more comorbidities. Residents of smaller cities were also less likely to be adherent than those in large cities.

A multivariate analysis showed that an increase in synchronization from the lowest to the highest groups resulted in an increase in the proportion of patients that were adherent, from 68.9% to 76.6%.

“Our results provide evidence that, even with the motivation of preventing a cancer recurrence, modifiable health delivery factors remain a barrier to appropriate medication use,” the authors wrote. “With the growth in oral anti-oncologic agents, interventions that simplify patients’ experiences are needed to foster optimal cancer outcomes.”

In an accompanying editorial, Christopher R. Manz, MD, wrote that the retrospective nature of the study means it cannot be stated definitively that synchronization causes the better adherence. “Patients who have better synchronization may differ from patients with poor synchronization in ways that are not captured in the data,” he wrote. “For instance, a woman who is proactive about picking up several refills during a single pharmacy visit may also be more likely to diligently take her endocrine therapy.”

Still, he noted that the data, along with other studies on pharmacy synchronization, suggest that simple interventions, especially targeting patients with low baseline adherence, could improve that adherence and thus outcomes.

“Much more work is needed to further explore the problem of adherence in oncology and to identify interventions to improve adherence and cancer outcomes,” Manz wrote, “whether by better managing toxicities, reducing financial stress, or simply making patients’ lives easier by synchronizing refills.”