Nonadherence With Thiopurine Immunomodulator and Mesalamine Medications in Children with Crohn Disease

Abstract

To assess the prevalence of adherence to prescribed medications in children with Crohn disease and to identify possible factors associated with nonadherence. This was a cross-sectional study of 51 pediatric patients with Crohn disease who were prescribed maintenance therapy with a thiopurine immunomodulator (6-mercaptopurine or azathioprine) and/or mesalamine during a 180-day period. Medication adherence rates were calculated from a validated formula using pharmacy records, and nonadherence was defined as a refill rate of <80% of the prescribed medication. Seventy-five percent of patients were prescribed thiopurine immunomodulators and 86% were prescribed mesalamine. The prevalence of nonadherence was 50% for the thiopurine immunomodulators and 66% for mesalamine. The mean number of emergency department visits for patients adherent to mesalamine was significantly greater than the nonadherent group (P < 0.0008). Having an emergency department visit increased the chances of a patient being adherent to mesalamine therapy by >9-fold (odds ratio, 9.6; 95% confidence interval, 1.87-52.17). The mean number of total health care visits was significantly greater for patients adherent to mesalamine (6.1 +/- 0.8) compared with those who were not adherent (3.0 +/- 0.4) (P < 0.001). These findings suggest that nonadherence to thiopurine immunomodulator or mesalamine therapy in pediatric patients with Crohn disease is common. Having a health care visit was associated with being adherent.