The Association of High-Quality Hospital Use on Health Care Outcomes for Pediatric Congenital Heart Defects in a Universal Health Care System

Introduction: Congenital heart disease (CHD) has an incidence of 0.8% to 1.2% worldwide, making it the most common birth defect. Researchers have compared high-volume to low-volume hospitals and found significant hospital-level variation in major complications, health resource utilization, and mortality after CHD surgery. In addition, researchers found critical CHD patients at low-volume/non-teaching facilities to be associated with higher odds of inpatient mortality when compared to CHD patients at high-volume/teaching hospitals (odds ratio 1.76). We examined the effects of high-quality hospital (HQH) use on health care outcomes and health care costs in pediatric CHD care using an instrumental variable (IV) approach.

Materials and methods: Using nationwide representative claim data from the United States Military Health System from 2016 to 2020, TRICARE beneficiaries with a diagnosis of CHD were tabulated based on relevant ICD-10 (International Classification of Diseases, 10th revision) codes. We examined the relationships between annual readmissions, annual emergency room (ER) use, and mortality and HQH use. We applied both the naive linear probability model (LPM), controlling for the observed patient and hospital characteristics, and the two-stage least squares (2SLS) model, accounting for the unobserved confounding factors. The differential distance between the patient and the closest HQH at the index date and the patient and nearest non-HQH was used as the IV. This protocol was approved by the Institutional Review Board at the University of Maryland, College Park (Approval Number: 1576246-2).

Results: The naive LPM indicated that HQH use was associated with a higher probability of annual readmissions (marginal effect, 18%; 95% CI, 0.12 to 0.23). The naive LPM indicated that HQH use was associated with a higher probability of mortality (marginal effect, 2.2%; 95% CI, 0.01 to 0.03). Using the differential distance of closest HQH and non-HQH, we identified a significant association between HQH use and annual ER use (marginal effect, -14%; 95% CI, -0.24 to -0.03).

Conclusions: After controlling for patient-level and facility-level covariates and adjusting for endogeneity, (1) HQH use did not increase the probability of more than one admission post 1-year CHD diagnosis, (2) HQH use lowered the probability of annual ER use post 1-year CHD diagnosis, and (3) HQH use did not increase the probability of mortality post 1-year CHD diagnosis. Patients who may have benefited from utilizing HQH for CHD care did not, alluding to potential barriers to access, such as health insurance restrictions or lack of patient awareness. Although we used hospital quality rating for congenital cardiac surgery as reported by the Society of Thoracic Surgeons, the contributing data span a 4-year period and may not reflect real-time changes in center performance. Since this study focused on inpatient care within the first-year post-initial CHD diagnosis, it may not reflect the full range of health system utilization. It is necessary for clinicians and patient advocacy groups to collaborate with policymakers to promote the development of an overarching HQH designation authority for CHD care. Such establishment will facilitate access to HQH for military beneficiary populations suffering from CHD.