Abstract 149: Utilization and Costs of Hospitalization among Adolescents and Young Adults with Congenital Heart Disease in California

Abstract

Background: Congenital heart disease (CHD) often requires intensive surgeries and care, especially in the early years of a CHD patient. However, it is not well understood how their health care utilization and costs vary as CHD patients transition into young adulthood. Objective: We aim to identify the utilization patterns of hospitalization by age among CHD patients 10-29 years old and to measure the associated costs as compared with the general population in California. Methods: We utilized the California State Inpatient Database (SID) and the Healthcare Cost and Utilization Project (HCUP) Cost-to-Charge Ratio Files 2005-2009. By merging the two datasets, we obtained data on about 97% of all hospital discharge records in California including principal and secondary diagnoses, principal and secondary procedures, admission and discharge status, basic patient demographics, total charges, imputed total costs, and length of stay (LOS). Hospital discharges of CHD patients were identified by one or more principal or secondary ICD-9 diagnosis codes of 745.xx, 746.xx, or 747.xx. Utilization and cost patterns were compared to the general population by 5-year age groups (10-14, 15-19, 20-24, and 25-29). We then conducted a multivariate linear regression with the CHD population to understand how age and other factors influence costs of hospitalization per stay. Results: The average hospitalization costs per stay among CHD patients remain 2-3 times as high as that of the general population across all age groups ($21-31k vs. $7k-12k). However, the total hospitalization costs of the CHD population monotonically decrease as patients with CHD age into adulthood: in 2005-2009, the total costs were $75m in the 10-14 group, $74m in the 15-19 group, $50m in the 20-24 group and $48m in the 25-29 group, which represented 3.8%, 1.7%, 0.8%, 0.7% of the total costs in the general population of the respective age group. The decline in total costs by age among the CHD population manifested in both decreasing numbers of hospitalizations and lower costs per stay. Other observed trends include increasing fraction of admissions from the emergency department (ED), decreasing fraction of surgery-related hospitalizations, and shorter LOS as CHD population age into adulthood. Regression results within the CHD population 10-29 years old (n=9680) suggest that costs per stay were positively associated with LOS (+$2674, p<.001) and were negatively associated with being 25-29 years old (-$3240, p<.001), being female (-$1935, p<.001), having no surgeries (-$16758, p<.001) or other procedures performed ($21396, p<.001), and being admitted from the ED (-$3638, p<.001). Conclusion: The CHD population incurs lower hospitalization costs as they age into young adulthood.