Beliefs regarding medication for chronic myeloid leukemia (CML) are strongly correlated with adherence to those medications, according to a study (abstract 9558) presented at the 2015 American Society of Clinical Oncology (ASCO) Annual Meeting held May 29 to June 2 in Chicago.
Tyrosine kinase inhibitors (TKIs) have dramatically changed outcomes with CML, but their use is generally considered lifelong. “Suboptimal adherence is common and adversely affects clinical outcomes and healthcare costs,” wrote study authors led by Joanne S. Buzaglo, PhD, of Cancer Support Community in Philadelphia, on their poster. “Patients with suboptimal adherence might under-recognize missed dose impact on response.”
The new study used data from the Cancer Experience Registry, a database of over 7,600 cancer survivors; it included nine disease-specific surveys, including one for CML. In this analysis, 393 CML patients who enrolled in the registry from October 2013 to July 2014 and answered a survey (81% response rate) were included. The median age of the participants was 59 years, most were female (68%) and white (90%).
The participants were asked to agree or disagree with two statements: “It is okay to miss a dose of my CML medicine every now and then,” and “I need to take every dose of CML medicine or it might not work.” They also reported missed TKI dose frequency.
Nineteen percent of the cohort reported missing a dose of oral CML medication at least once per month; 14% said they postponed filling prescriptions, and 10% said they skipped dosages of prescribed CML medication.
With regard to the first statement, 74% strongly agreed that it is okay to miss a dose every now and then; 34% agreed, 15% disagreed, and 6% strongly disagreed. Compared with the participants who either disagreed or strongly disagreed with the statement, those who agreed or strongly agreed were more likely to have reported missing doses monthly, with an odds ratio (OR) of 7.04 (95% confidence interval [CI], 3.65–13.57).
A similar result was seen with regard to the second statement. Thirty-two percent of participants strongly disagreed that they need to take every dose or it might not work, while 45% disagreed; 22% agreed with the statement, and 5% strongly agreed. Those who disagreed/strongly disagreed were significantly more likely to have reported missing doses at least once monthly than those who agreed/strongly agreed (OR = 5.36; 95% CI, 2.81–10.2).
The authors concluded that these patients’ beliefs regarding medication are strongly associated with suboptimal adherence. “The results suggest the need for multifaceted patient education that could have a positive impact on adherence and survival,” they wrote.