BACKGROUND AND OBJECTIVES: Genetic testing is critical for optimal diagnosis and management of pediatric neurology patients, but access is challenging. We investigated whether social determinants of health (SDOH) were associated with genetic testing among pediatric neurology patients in a retrospective observational study. METHODS: Electronic health record data were extracted from pediatric outpatients (0-18 years) evaluated at a single tertiary care institution between July 2018 and January 2020. Genetic testing requests, insurance denials, and test completion rates were compared among non-Hispanic single-racial or multiracial Black (Black) vs non-Hispanic single-racial White (White) patients. SDOH and clinical variables including ethnoracial identity, insurance type, Area Deprivation Index, rural urban commuting area, sex, age, diagnoses, and number of neurology visits were evaluated to identify associations with chromosomal microarray (CMA), multigene panel (MGP), and exome/genome sequencing (ES/GS) test completion. RESULTS: Of 11,371 patients (mean age 9.25 years
46.1% female), 554 (4.9%) completed ≥1 genetic test in the study interval, with White patients nearly twice as likely to have completed ≥1 genetic test compared with Black patients (aOR 1.88, 95% CI 1.41-2.51). Outpatient pediatric neurology was the most common specialty through which testing was completed. Neurology provider request rates for genetic testing did not differ by patient ethnoracial identity, but insurance denial rates after neurology request were lower for White vs Black patients (relative rate ratio [RR] 0.44, 95% CI 0.27-0.73), and those with public insurance were less likely to complete genetic testing after it was requested through neurology (aOR 0.59, 95% CI 0.35-0.97). However, when considering individual genetic test types completed through any specialty, insurance type was significantly associated only with MGP completion (public vs private OR 0.56, 95% CI 0.40-0.77), not CMA or ES/GS. DISCUSSION: Marked ethnoracial disparities in genetic testing completion were identified despite equivalent rates of genetic testing requests by neurologists. While Black patients had higher rates of insurance denials, insurance type itself accounted for the disparity in MGP but not CMA or ES/GS completion. Other unmeasured barriers stemming from systemic racism likely affected genetic testing among Black patients.