311 - Ten year genetic testing utilization and outcome trends within a large neonatal network

Poster Number: 311
Publication Number: 311.441

Marina Metzler, Nationwide Children's Hospital, Columbus, OH, United States; Austin A. Antoniou, Nationwide Children's Hospital, Columbus, OH, United States; Bimal P. Chaudhari, Nationwide Children's Hospital, Columbus, OH, United States

Background: Genetic diagnoses in the NICU have been associated with increased length of stay and cost. Diagnosing genetic diseases is challenging but has proven beneficial to NICU providers and families. With increasing availability of different testing modalities there have been aims to shorten time to diagnosis to provide treatments earlier as well as decreasing healthcare costs, but these trends have not been well described.  

Objective: To determine trends in genetic diagnosis timing and test type utilization in NICU patients. 

Design/Methods: We performed a retrospective study of all infants who were admitted to a Nationwide Children’s Hospital (NCH) Neonatal Network NICU from 2010 to 2020. Subjects were identified as having genetic testing if one more genetic tests including FISH, karyotype, microarray, single gene, gene panel, exome or genome was ordered. The dates of the first genetic test and last genetic test result were determined. Subjects were categorized into one of four mutually exclusive groups: no test, all tests and results during NICU admission, tests during NICU admission and last result outpatient, and all tests and results outpatient. Test diagnostic status was determined by medical record review.   

Results: Of the 22,212 patients admitted to NCH Neonatal Network NICUs in the study period, 1640 (7.4%) patients had one or more genetic tests (Table 1). Of the 1640 subjects with a genetic test, 294 (17.9%) received a genetic diagnosis (Table 2). Mean age at diagnosis trended down over time from 993.1 days to 92.6 days (p=0.00015; Figure 1). Long diagnostic odysseys became less common over time with the 95%ile for age at diagnosis falling from 3596.8 days to 365.4 days (p=6.4x10^-5; Figure 1).  Array was the most ordered genetic test in any given year (mean=145.5). There was a statistically significant increase in the use of exome/genome orders by birth year (p=0.0021). Most subjects had their testing started during the initial hospitalization (Nf1004, 61.2%). However, most received at least one result after discharge (Nf1031, 62.9%).   Conclusion(s): With advances in testing over time there is increased utilization of exome/genome sequencing in a single large neonatal network. Despite decreased time to diagnosis, most diagnoses are made after discharge. This may be due to the additional presentation of clinical and developmental features that warrant further testing, or it may reflect delays in diagnoses that can be made in the NICU. The extent to which these trends affect cost, improve outcomes and/or patient/family experience are not yet known.  
Table 1. Genetic testing and result timing
Table 2. Demographics