A higher prescription co-payment, especially among older women, is associated with both early discontinuation and incomplete use of adjuvant aromatase inhibitor therapy, a lifesaving therapy for women with hormone sensitive early-stage breast cancer.
Dawn L. Hershman, M.D., M.S., associate professor of medicine and epidemiology and co-director of the Breast Cancer Program at the Herbert Irving Comprehensive Cancer Center at Columbia University, presented detailed study results at the 33rd CTRC-AACR San Antonio Breast Cancer Symposium, held Dec. 8-12, 2010.
Previous research has identified several factors affecting patient compliance with use of adjuvant aromatase inhibitors, such as young and old age, severity of side effects and belief that the medication is useful.
Hershman and colleagues examined the impact of prescription co-payments on hormone therapy use. Working with the Medco Research Institute , a wholly-owned subsidiary of Medco Health Solutions Inc., anonymous patient information was used to target women older than 50 years who were prescribed aromatase inhibitors for early breast cancer.
?We looked at two different factors: women who discontinued use altogether or had no subsequent refills and those that did not refill their prescription on time or did not take the medication at least 80% of the time,? said Hershman.
Results showed that of the 8,110 women aged 50 to 65 years, 21.1 % stopped taking the medication and of those who properly continued with their regimen 10.3% did not take the medication as directed over the two-year period. Of the 14,050 women 65 years or older, almost 25% stopped taking the medication and of those who continued, 8.9% were non-adherent.
Co-payments were categorized as less than $30, between $30 and $89.99, and $90 or more. The 90-day co-payments ranged from $0 to $893.49.
In the 65 and older group, women were more likely to discontinue medication use if they fell in the co-payment categories above $30. However, it was not until the co-payment reached $90 or more that the less than 65 age group was more likely to discontinue use or not take it as prescribed.
Additionally, the study results showed that women whose prescriptions came from a primary care doctor or women who were prescribed many other medications were also more likely to stop taking the medications or not take them as prescribed.
?When we have highly effective medications available, we need to try to set limits on potential barriers to use like co-payments,? said Hershman. Based on these findings, ?future public policy efforts should be directed towards reducing financial constraints as a means of increasing the complete use of these medications.?