Specialty Pharmacy Improves Adherence to Imatinib | Page 3

Published Online: December 05, 2013
Jay Visaria, PhD, MPH; Rochelle Henderson, PhD, MPA; and Sharon Glave Frazee, PhD, MPH
During the follow-up period, patients in the specialty pharmacy group had greater odds of being adherent (a PDC of at least 90%) (unadjusted odds ratio [OR] = 1.87, 95% confi dence interval [CI], 1.36-2.58) compared with patients in the other pharmacy group. After adjusting for confounders, patients in the specialty pharmacy group were signifi cantly more likely to achieve optimum imatinib adherence (adjusted OR = 1.46, 95% CI, 1.02-2.09; Table 2). When we examined the second outcome, continuous PDC, we found that the unadjusted average PDC for imatinib was greater for the specialty pharmacy group than for patients in the other pharmacy group (75.78% vs 60.37%; P <.0001). After multivariate adjustment using ordinary least squares, controlling for known confounders, and setting all model coeffi cients to their mean values, the adjusted PDC for specialty pharmacy patients was 74.14% versus 63.34% in the other pharmacy group (P <.0001).


Our study found that patients who used a specialty pharmacy that provided refill reminders and comprehensive clinical care management programs to fill a majority of their imatinib prescriptions had a significantly higher likelihood of attaining optimum imatinib adherence compared with those using other dispensing channels for a majority of their 30-day adjusted imatinib prescriptions.

Adherence to imatinib has been associated with lower healthcare costs. A study of US commercially insured CML patients starting imatinib therapy found that those with medication possession ratios (MPRs) of 85% and above incurred $17,727 less in total healthcare costs over a 12-month follow-up period than patients with lower MPRs.8 Another study of CML patients found that a 10% using a retail pharmacy. In the same study, specialty pharmacy patients had 13% lower total healthcare costs (medical and pharmacy) compared with retail pharmacy patients over a 12-month follow-up period.16

Goals proposed by the National Comprehensive Cancer Network Task Force on Specialty Pharmacy include maximizing adherence, optimizing clinical outcomes, and improving economic outcomes.14 The specialty pharmacy investigated in this study offered patients a  number of interventions and programs to attain these goals. From the initiation of imatinib therapy, patients using the specialty pharmacy had access to oncology-trained nurses and pharmacists for disease and drug education and support. Planned, proactive interactions also allowed for detection of potential side effects, medication errors, and premature discontinuation of therapy. In addition, adherence monitoring and refi ll reminders affected the imatinib adherence of specialty pharmacy patients.

There are several limitations to this study, a number of which result from the exclusive use of pharmacy claims data for this analysis. Because integrated medical claims and patient chart data were unavailable, patients could not be selected or stratifi ed based on medical diagnosis or cancer stage. Disease severity could not be controlled for in the multivariate adjustment. The PDC calculation did not adjust for time spent in the inpatient setting among those patients who were admitted. A proxy to control for the impact of medication burden on adherence was created, but this proxy did not completely capture comorbidity burden. A possession-based measure of adherence was used as the study outcome, assuming that any imatinib possessed by the patient was taken as prescribed. Similar measures have been used in earlier studies.8,9 A 6-month preindex period was used to select imatinib patients starting a new course of therapy. It is possible that all study patients may not have been imatinib naïve at the time of the index imatinib claim in this study, which may have had an infl uence on imatinib adherence.

The findings from this study are generalizable only to commercially insured patients with PBM-administered pharmacy benefits. Additionally, some patients in the other pharmacy group may have obtained the majority of their medications from another specialty pharmacy. However, it has been reported that specialty pharmacies have a wide range of pharmacy delivery models and offer a variety of oncology care management interventions.14 Because the specific care model of each external specialty pharmacy or retail pharmacy could not be determined, all patients using one of these channels for a majority of their imatinib prescriptions were combined into a single comparator group. Patients in the other pharmacy group may have been provided with intensive and comprehensive oncology care through their pharmacy; thus, this analysis represents a conservative estimate of the impact of specialty pharmacy on imatinib adherence. Finally, this study may be biased because of the “healthy adherer” effect. Patients who generally espouse healthy behaviors may select specialty pharmacy over other channels to take advantage of the more intensive and disease-focused approach of this channel and may also be more motivated to be adherent to medications. It is possible that part of the superior adherence observed in specialty pharmacy may be explained by a greater proportion of healthy adherers using specialty pharmacy, rather than channel characteristics.


This study found that commercially insured patients using specialty pharmacy integrated with refi ll reminders and a comprehensive oncology care management program were 46% more likely to achieve optimum adherence to imatinib compared with patients who did not use the specialty pharmacy. With an increasing number of oral medications for cancer entering the marketplace,12 patient adherence is an increasingly important determinant of treatment success. Plan sponsors, payers, and patients may benefit from a pharmacy model used by the specialty pharmacy evaluated in this study for the dispensing and use of oral oncology medications.

Take-Away Points

  •  Adherence to imatinib has been associated with lower healthcare costs. With the annual cost of therapy reported to be $92,000 in 2012 and patientsstruggling to remain adherent to imatinib, payers are looking for ways to increase medication adherence, avoiding unnecessary/wasted healthcare costs.

  • This study found patients who used specialty pharmacy were 46% more likely to achieve optimum adherence to imatinib compared with patients who used other dispensing channels.

  • Specialty pharmacy interventions such as proactive oncology care management and refill reminders may help more patients achieve optimum adherence to imatinib.
Author Affiliations: From Express Scripts Holding Company (JV, RH, SGF), St. Louis, MO.

Funding Source: This study was funded by Express Scripts Holding Company.

Author Disclosures: The authors (JV, RH, SGF) report no relationship or financial interest with any entity that would pose a confl ict of interest with the subject matter of this article.

Authorship Information: Concept and design (JV, RH, SGF); acquisition of data (JV); analysis and interpretation of data; drafting of the manuscript (JV, RH, SGF); critical revision of the manuscript for important intellectual content (JV, EH, SGF); statistical analysis (JV); provision of study materials or patients (SGF); obtaining funding (SGF); administrative, technical, or logistic support (RH, SGF); and supervision (RH, SGF).

Address correspondence to: Jay Visaria, PhD, MPH, Express Scripts Holding Company, 4600 North Hanley Rd, MS: PTIC08, St. Louis, MO 63134. E-mail: jvisaria@express-scripts.com.
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