ASH 2015: Researchers Identify Children Most at Risk of Overreporting Adherence to At-Home Chemotherapy Regimen
A study presented by Landier et al at the 57th American Society of Hematology (ASH) Annual Meeting examined the common problem of children in remission from acute lymphocytic leukemia (ALL) not adhering to their maintenance drug regimens, thus putting them at risk of relapse (Abstract 82).
6-mercaptopurine (6MP) is an oral chemotherapy drug often used to treat ALL, the most common blood cancer in children. While taking 6MP daily during maintenance therapy as prescribed by a doctor is critical to sustaining durable remissions, not all children take their medicine as directed.
Asking patients to self-report their intake of 6MP is convenient, inexpensive, and helps doctors understand if doses are being missed and interventions are needed. However, previous studies not related to oncology show that patients often report that they took their medicine even if they missed doses.
This study aimed to compare self-reported 6MP intake with electronic monitoring to identify predictors of overreporting of 6MP intake.
Study Findings
Participants included 416 children with ALL in their first remission who were prescribed oral 6MP. The patients’ ages ranged from 2 to 20 years old.
Treatment intake for each patient was measured electronically using a system that recorded each date and time the 6MP bottle was opened during a span of 4 months. At the end of each of the 4 months, the child or parent reported the number of days that 6MP had been taken during the preceding month.
Patients were then categorized as perfect reporters if the self-report matched the electronic report, overreporters if the self-report indicated more doses than the electronic report by 5 or more days per month for more than half of months of monitoring, or “others.”
Only 12% of patients were identified as perfect reporters; 23.6% were overreporters, and 64.4% were considered “others”.
Upon further analysis, researchers found that for each increasing year of age of the child, the risk of overreporting increased by 7%. Race was also a factor, as Hispanic children/parents were 2.4 times more likely to overreport, Asians were 3.1 times more likely to overreport, and African Americans were 5.3 times more likely to overreport when compared with non-Hispanic white children/parents. Children whose father did not attend college were 2.1 times more likely to overreport.
Finally, children who did not adhere to their 6MP regimen (ie, those whose adherence rate was less than 95% of prescribed doses) were 8.6 times more likely to overstate their monthly doses, when compared with children who adhered to prescribed 6MP. While 78.6% of overreporters were nonadherent, only one of 50 (2%) of the perfect reporters was nonadherent.
Researchers concluded that approximately 25% of children/parents overreport 6MP intake and that overreporting is more likely in patients who are nonadherent to 6MP, older, of a minority race, and from households with lower paternal education.
These findings suggest that subjective reporting of 6MP ingestion during maintenance therapy for childhood ALL should be used with caution.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
