Trends in Congenital Heart Disease Hospitalizations: What Nearly 50 Years of Longitudinal Data and Segmented Regression Reveal

Background Understanding long‐term health care utilization patterns in congenital heart disease (CHD) is essential for optimizing care delivery. While previous studies often assume linear trends, such assumptions could provide flawed analysis if abrupt changes in treatment or care occur, causing nonlinearity in trends. This study aims to determine if and where significant nonlinearity exists in hospitalization trends within the CHD pediatric population. Methods Using national Swedish registers, we conducted a retrospective cohort study using segmented regression analysis of pediatric CHD health care utilization from infancy through adolescence, stratified by disease complexity. Breakpoints were identified to assess changes in trend over time, and subgroup analyses compared segmented and linear regression models. Results Segmented regression revealed distinct utilization patterns across age groups, with highest health care use in infancy followed by a progressive decline through childhood and adolescence. Contrary to prior research, utilization declined over time regardless of CHD complexity. Identified breakpoints within the general CHD pediatric population in 1978, 1985, 1992, and 2003 aligned with key developments in CHD care. Conclusions These findings challenge prevailing assumptions of increasing health care use over time among the pediatric CHD population. Given the identified breakpoints, caution is warranted when conducting comparative analyses that span these periods, as doing so may obscure meaningful shifts in underlying trends.