Medical Resource Utilization of Outpatient Care for Children with Neurofibromatosis Type 1

Background: Neurofibromatosis Type 1 (NF1) is an autosomal dominant syndrome with manifestations affecting the central nervous system, musculoskeletal system, peripheral nervous system, and cognitive/behavioral functions. Many of these manifestations persist throughout life and require medical/surgical interventions. The resource utilization and economic burden of caring for children with NF1 is unknown. Prior research has inherent selection bias and does not accurately reflect the incidence/resource utilization of morbidities. In order to identify which disease manifestations are in the most need of improved clinical algorithms and novel therapeutics, the frequency/type of resources utilized (i.e., diagnostic imaging and specialty visits) must be determined. The current study sought to identify which manifestations of NF1 utilize the most healthcare resources and to validate the accuracy of using International Classification of Diseases, Ninth Revision (ICD-9) diagnostic codes to identify patients with NF1. Methods: The electronic health record at The Children\u27s Hospital of Philadelphia was queried to identify patients seen between January 2011-December 2015 with the ICD-9 code 237.71. Subjects were excluded if the clinical/genetic diagnosis could not be confirmed. For eligible subjects, the frequency of disease manifestations, MRI scans, and specialty visits over the five-year study period were recorded. The positive predictive value (PPV) of identifying subjects using the ICD-9 code was calculated. Results: Nine-hundred-eleven subjects with NF1 were included (ages 0.7-69.5 years, median = 12.9; 51% female). Fifty-four patients could not be confirmed and were excluded. The most common manifestations were cognitive/behavioral (42%), CNS abnormalities (37%), plexiform neurofibromas (32%), MSK (21%) and other (19%). A total of 13,643 outpatient provider visits occurred with Ophthalmology (18%) and Oncology (23%) being the most frequent. Subjects underwent a total of 4,527 MRI scans, 63% required sedation. Brain MRIs were the most common (N = 2,161). Treatment with prescription medications occurred in 13% of subjects for cognitive/behavioral disorders. The 237.71 ICD-9 code accurately identified subjects with a confirmed diagnosis of NF1 (PPV = 94.4%) if the code was present once in the subject’s chart. The PPV increased to 98.2% if at least two subject visits were coded. Conclusions: To our knowledge, this is the first study to describe medical resource utilization, based on disease manifestation, in children with NF1. CNS manifestations required the highest frequency of MRI acquisitions and specialty visits. The ICD-9 code 237.71 accurately identified subjects with NF1