Who Cares for Medicaid-Enrolled Children With Chronic Conditions?

DISCUSSION

This study provides the first data regarding rates of relevant subspecialist use by Medicaid-insured children with a range of chronic conditions. These children with chronic health conditions use generalist care much more commonly than relevant subspecialist care. Although no clear guidelines or standards of care define appropriate numbers of relevant subspecialist visits for children with chronic conditions, most of these children had no identified relevant subspecialty visit in the study year. Among the conditions studied, only children who were enrolled in SSI and had spina bifida, seizure disorder, and congenital heart disease and children who were not enrolled in SSI and had seizure disorder, congenital heart disease, and cerebral palsy had a >50% likelihood of any relevant subspecialty visit in 1 year. These rates do not include use of developmental pediatricians, and they likely would increase if we included developmental pediatricians. Children with the most common chronic conditions generally had lowest rates of subspecialist use, perhaps reflecting primary care providers' comfort and knowledge in the care of these children. The notable exception to this pattern was children with mental retardation, who had relatively high rates of use of any relevant subspecialist among children without SSI. In general, younger children were more likely to use any relevant subspecialists and relevant pediatric subspecialists, likely reflecting greater difficulties in assessing many of these conditions and their complications in younger children. In general, children who had chronic conditions and lived in urban areas had higher rates of relevant pediatric subspecialist use than children who lived in nonurban areas. This finding supports the hypothesis that supply influences utilization; there is greater availability of pediatric subspecialists and children's hospitals in urban areas. Similarly, case mix as measured by the ACG score was associated with greater subspecialist use (any relevant subspecialist and relevant pediatric subspecialist), suggesting that subspecialists are used more when the illness burden is greater.

The much higher use of generalist services (in comparison with subspecialty services) in this study suggests that most of these children have access to primary care (although our data provide no information on the content, scope, or quality of that care). Thus, concerns that these chronic conditions may shunt children into subspecialty settings to the detriment of their receipt of primary care seem unsupported by our data. Indeed, this study suggests that these children and their families use primary care providers for most of their health care needs, including those that arise from their chronic condition.

We had expected to find higher rates of relevant subspecialty utilization for these children with complex chronic conditions, especially the less common conditions, although, admittedly, no clear standards for such use exist. Given the increasingly rapid growth of new technologies for many of these conditions, primary care physicians may face difficulties in keeping up with advances in the care for less common conditions and therefore may rely increasingly on subspecialty care for advice and consultation. Some of these conditions may not merit yearly or more frequent subspecialist visits (eg, asthma, cerebral palsy), and others may have periods of much stability (eg, congenital heart disease). For example, an older child with spina bifida may have no ongoing renal or new orthopedic problems and therefore have less need for regular subspecialty services. Nonetheless, other conditions for which frequent changes in status and technology occur (eg, hemophilia, AIDS) might indicate a need for subspecialist consultation. When we examined a sample with 2 full years of claims data, however, rates of subspecialty use rose only marginally. A limitation of the data is that informal consultations or telephone discussions between primary care providers and subspecialists do not lead to claims and were not identified in this study.

These findings cannot be generalized to children with private insurance or children who lack health insurance, both of whom may experience different rates of subspecialty use. The Medicaid population includes large numbers of children with moderate and severe chronic conditions. Children with Medicaid coverage may experience particular difficulty with access to subspecialty services, given limited resources and barriers to care from lack of transportation or cultural or language differences and the potential unwillingness of subspecialty providers to accept Medicaid patients.

The data presented here have several limitations that relate to the use of claims data to describe patterns of subspecialty use. First, the identification of chronic conditions reflects the diagnoses listed by physicians and recorded into the Medicaid database. Physicians may use an acute illness code when they see a child with a chronic condition, leading to underidentification of children. This problem, however, should have affected generalists more than subspecialists. Alternatively, we may identify children as having a condition that they do not actually have, because the child has erroneous codes or rule-out codes. We attempted to limit the impact of this type of error by using more stringent identification criteria when rule-out diagnoses were most likely. Because children with SSI must prove that they have a substantial disability to enroll in the program, these children should have at least 1 chronic condition or disability, although it may not be 1 of the 11 study conditions. Overidentification of children could help explain the low rates of visits to relevant subspecialists. Second, the identification of subspecialists as pediatric required a merge of Medicaid information to AMA subspecialty information. This strategy likely underidentifies subspecialists as pediatric. It also requires that the AMA correctly designate subspecialty status. Providers change their designation from specialists to generalists and the reverse at low rates,¹⁹ likely improving accurate designation, yet providers may spend time practicing in areas other than their reported subspecialty.^20,,21 Identification of a provider's subspecialty type is sensitive to whether all AMA subspecialty fields are used to identify subspecialists.²⁰ We used both the primary and secondary provider codes to capture all possible subspecialists. When we were not able to identify subspecialists (eg, developmental pediatricians), we underestimated rates of use. Third, the results presented here represent only children who are enrolled in Medicaid fee-for-service programs, because we excluded those with health maintenance organization or private insurance. Finally, children's hospitals and other organized pediatric services in general hospitals (usually academic health centers) provide a large amount of subspecialty care for children with chronic conditions. These institutions typically are found in cities with relatively few pediatric subspecialists in community settings (in distinction to adult subspecialists). These tertiary care institutions may have had inadequate systems in place for billing Medicaid for their services, and their services may be underrepresented in our data, thereby reducing the apparent use of subspecialty (and especially pediatric subspecialty services) by study children. In addition, for the cases for which we identified subspecialty status on the basis of procedure codes, we may have underidentified subspecialist visits.

These data provide a baseline of use of subspecialists before sizable use of managed care for Medicaid-enrolled children, for whom access to subspecialists and pediatric subspecialists may be more limited.²² For this population, shifts to managed care and the associated requirements that children have a generalist primary care physician may not change care patterns as much as expected.