Adherence to oral medications during maintenance therapy is essential for pediatric patients with acute lymphoblastic leukemia. Self-reported or electronic monitoring of adherence indicate suboptimal adherence, particularly among particular sociodemographic groups. This study used medication refill records to examine adherence among a national sample of pediatric patients with acute lymphoblastic leukemia. Patients in a national claims database, aged 0 to 21 years with a diagnosis of acute lymphoblastic leukemia and in the maintenance phase of treatment, were included. Medication possession ratios were used as measures of adherence. Overall adherence and adherence by sociodemographic groups were examined. Adherence rates were 85% for 6-mercaptopurine and 81% for methotrexate. Adherence was poorer among patients 12 years and older. Oral medication adherence rates were suboptimal and similar to or lower than previously documented rates using other methods of assessing adherence. Refill records offer a promising avenue for monitoring adherence. Additional work to identify groups most at-risk for poor adherence is needed. Nurses are well positioned to routinely monitor for medication adherence and to collaborate with the multidisciplinary team to address barriers to adherence.
Keywords: acute lymphoblastic leukemia; maintenance therapy; oral medication adherence; pediatric cancer; risk factors.