Correspondence between objective and subjective reports of adherence among adolescents with acute lymphoblastic leukemia

This study examined the relation between self-reported oral medication adherence and bioassay adherence indicators among adolescents with acute lymphoblastic leukemia (ALL). Fifty-one adolescents with ALL, who were prescribed 6-mercaptopurine (6MP), were recruited. Adherence was assessed via 6MP metabolites at Days 28, 56, and 112 and adolescent report at Days 56 and 112. Forty-five percent of adolescents reported missing a dose of 6MP, and 53% had bioassay results indicative of nonadherence. Adolescents with lower self-reported adherence were 3.5 times more likely to have low levels of 6MP metabolites. Both self-report and bioassay data confirm the prevalence of 6MP nonadherence among adolescents with ALL.