Impact of medication non-adherence on survival after pediatric heart transplantation in the USA

Abstract

Background Medication non-adherence (NA) can result in life-threatening illness in children after solid-organ transplantation. Little is known about the incidence, risk factors and outcomes of NA in large numbers of pediatric heart transplant (HT) recipients. Methods Organ Procurement Transplant Network (OPTN) data were used to identify all children <18 years of age in the U.S.A. who underwent HT from October 1999 to January 2007. Cox proportional hazards analysis was used to identify risk factors for NA and the effect on graft survival. Results Of 2,070 pediatric heart transplants performed the median age at transplant was 6 years (interquartile range [IQR] 0 to 13 years); 40% had congenital heart disease (CHD), 7% were re-transplants, 42% were non-white and 43% had Medicaid insurance. Overall, 186 (9%) children had a report of NA at a median age of 15 years with more than two-thirds of NA episodes occurring after 12 years of age. Factors independently associated with NA were: adolescent age at transplant (hazard ratio [HR] 7.0, 95% confidence interval [CI] 4.1 to 12, compared with infants); black race (HR 2.3, 95% CI 1.7 to 3.3, compared with white); Medicaid insurance (HR 2.0, 95% CI 1.5 to 2.7, compared with non-Medicaid insurance); and ventilator or ventricular assist device (VAD) support at transplant. The risk of mortality conditional upon report of NA was 26% at 1 year and 33% at 2 years. Conclusions Medication NA is an important problem in pediatric HT recipients and is associated with high mortality. Adolescent age, black race, Medicaid insurance and invasive hemodynamic support at transplant were associated with NA, whereas time on the wait list and gender were not. Targeted interventions among at-risk populations may be warranted.