OBJECTIVES: Severe mucopolysaccharidosis (MPS) Type I (or Hurler syndrome) is a rare recessive genetic disorder caused by an enzyme deficiency which may be treated with hematopoietic stem cell transplant and/or enzyme replacement therapy. Without treatment, children experience significant, rapid physical and cognitive decline and premature death. The purpose of this study was to assess utilization and costs of outpatient healthcare services in the US using a retrospective claims database.

METHODS: The data source was Symphony Health Integrated Dataverse (IDV), a longitudinal database representing roughly 85% of the US population. All de-identified medical and pharmacy claims data from January 2012-June 2017 were included among patients <18 years of age with at least 12 continuous months of coverage and at least two target diagnosis codes (ICD-10 E76.01) within a 3-month period. Birth date was estimated using year of birth + July 1. Total paid amounts (by payer, patient, or both) on outpatient claims were adjusted to 2017 using 5% per annum to calculate cost per patient per month (PPPM).

RESULTS: A total of 310 patients were included in the analysis: mean age was 5.3 years (std=4.5), 66% were male, and patients resided among 45 states. A total of $135,531,809 was paid for outpatient healthcare services over 12,648 patient months for an average cost PPPM of $10,715. Outpatient PPPM costs were $385 for imaging; $633 for laboratory; and $1,565 for provider services. Other outpatient services and supplies such as medication infusions, surgical procedures, home services, and parenteral nutrition totaled $9,469 PPPM. Of the 310, 180 had 12+ months of continuous retail pharmacy claims. Total PPPM pharmacy costs were $3008.

CONCLUSIONS: This analysis demonstrates that children with severe MPS I incur substantial direct medical costs. Further studies are needed to quantify the burden of this rare disease in terms of direct and indirect costs of care.