To quantify the use of adult-trained medical subspecialists by children and to determine the association between geographic access to pediatric subspecialty care and the use of adult-trained subspecialists. Children with limited access to pediatric subspecialty care may seek care from adult-trained subspecialists, but data on this practice are limited.

We identified children aged <16 years in 2007-2012 Pennsylvania Medicaid claims. We categorized outpatient visits to 9 selected medical subspecialties as either pediatric or adult-trained subspecialty visits. We used multinomial logistic regression to examine the adjusted association between travel times to pediatric referral centers and use of pediatric vs adult-trained medical subspecialists for children with and without complex chronic conditions (CCCs).

Among 1.1 million children, 8% visited the examined medical subspecialists, with 10% of these children using adult-trained medical subspecialists. Compared with children with a ≤30-minute travel time to a pediatric referral center, children with a >90-minute travel time were more likely to use adult-trained subspecialists (without CCCs: relative risk ratio [RRR], 1.94, 95% CI, 1.79-2.11; with CCCs: RRR, 2.33; 95% CI, 2.10-2.59) and less likely to use pediatric subspecialists (without CCCs: RRR, 0.66; 95% CI, 0.63-0.68; with CCCs: RRR, 0.76, 95% CI, 0.73-0.79).

Among medical subspecialty fields with pediatric and adult-trained subspecialists, adult-trained subspecialists provided 10% of care to children overall and 18% of care to children living >90 minutes from pediatric referral centers. Future studies should examine consequences of adult-trained medical subspecialist use on pediatric health outcomes and identify strategies to increase access to pediatric subspecialists.