Age-Related Iron Chelation Utilization and Healthcare Costs in Patients with Sickle Cell Disease (SCD)
Authors: Blinder Morey A. , Vekeman Francis , Trahey Alex , Sasane Medha , Paley Carole S. , Duh Mei Sheng 
Published: October 2019

Abstract
Abstract 338

Background:
For patients (pts) with SCD receiving regular blood transfusions (tf), iron chelation therapy (ICT) alleviates complications associated with iron overload. Pediatric pts tend to receive comprehensive care, including blood tf to avoid SCD-related complication and, as necessary, ICT. However, as pts transition to adult care, follow up is less constant and discrepancies are seen in care management. The aim of this study is to evaluate tf patterns, utilization of ICT among chronically transfused pts, and healthcare costs in pediatric and adult pts with a focus on the transitioning period from pediatric to adult care.

Methods:
State Medicaid data from the FL (1998–2009), NJ (1996–2009), MO (1997–2010), IA (1998–2010), and KS (2001–2009) were used for this study. Pts with ≥2 SCD diagnoses (ICD-9 282.6x) and ≥1 tf following the 2nd SCD diagnosis were included. Pts were followed for as long as they were enrolled in Medicaid. Pts were considered chronically transfused from the time of their 8th tf. Each tf event was defined as a unique day when ≥1 procedure code for packed RBCs, whole blood, or exchange tf was recorded. Quarterly rate of tf was calculated among all SCD pts and proportion of pts receiving ICT was calculated among pts who received ≥8 tf. Quarterly healthcare costs, stratified by outpatient (OP) and inpatient (IP) services and prescription drug (Rx) costs were calculated. Regression analyses were conducted to identify the main drivers of healthcare costs among pts with ≥8 tf. Covariates included, among others, transition age (<18 vs ≥18 yrs), SCD complications (pain, infection, stroke, cardiomyopathy, renal disease, and Moyamoya disease), current and previous tf, prescription of hydroxyurea, relevant comorbidities, and resources utilization.

Results:
3,208 pts were included (FL: 1,550, NJ: 992, MO: 489, KS: 121, IA: 56) in the study. Each pt was observed for an average (SD) of 6.0 (3.1) yrs. 917 pts received ≥8 tf during their observation period. The proportion of pts with ≥8 tf increased from 4% at 2 yrs of age to approximately 24% at 16 yrs old (Fig 1). The proportion of pts with ≥8 tf remained relatively stable around 20% thereafter, in contrast with the overall rate of tf which decreased after age 16. The proportion of chelated pts increased from 4% at 2 yrs of age to a maximum of 50% at age 13 (Fig 1). The proportion of chelated pts then decreased steadily during the following 10 yrs to reach 10% at age 23 and oscillated around that level thereafter. Healthcare costs increased from ages 5 to 19 for all SCD pts ($3,907 to $10,317 per pt-quarter) and those with ≥8 tf ($4,500 to $15,078 per pt-quarter), and remained high through adulthood. Pts with ≥8 tf had greater healthcare costs than the overall SCD population at all ages. Despite the higher Rx costs, pts receiving ICT incurred statistically significantly lower IP costs than chronically transfused pts receiving no ICT, resulting in no statistically significant cost difference (unadjusted cost difference, Rx: $2,285, p<.001; OP: $851, p=.156; IP: -$2,584, p<.001; total: $552, p=.493 [Table 1]; adjusted cost difference, Rx: $2,746, p<.001; OP: -$813, p=.036; IP: -$936, p<.001; total: $61, p=.098). Regression analyses also revealed that SCD complications was the main driver of healthcare costs among pts with ≥8 tf (incremental cost increase: $3,955; p<.001).

Conclusions:
Pts transitioning to adult care received less tf and ICT when chronically transfused, and had higher healthcare costs than pediatric pts. While other age-related factors are likely to impact SCD treatment patterns and healthcare resource utilization, the marked decrease in tf and proportion of chelated pts and increase in healthcare costs during the transition from pediatric to adult care suggest that tf and ICT are markers for lower healthcare costs in SCD patients.

Disclosures:
Blinder: Novartis: Honoraria. Vekeman:Analysis Group: Analysis Group has received research grant from Novartis pharmeceuticals, Employment. Trahey:Analysis Group: Analysis group received research grant from Novartis Pharmaceuticals, Employment. Sasane:Novartis Pharmaceuticals: Employment. Paley:Novartis Pharmaceuticals: Employment. Duh:Analysis Group: Analysis group received research grant from Novartis Pharmaceuticals, Employment.