Critical congenital heart disease (CCHD) refers to a group of heart defects that cause serious, life-threatening symptoms in the neonatal period and requires timely surgical or catheter interventions. We tried to explore current status of CCHD burden and the effect of early diagnosis of CCHD to mortality using the Korean national health insurance (NHI) data.

We analyzed the national health insurance (NHI) data from 2014 to 2018. We identified CCHD patients using the diagnosis codes and intervention codes from the claim data and the prevalence, mortality and medical expenditure of CCHD were analyzed. We linked neonatal data with their mother’s medical claim data and developed retrospective cohort data set for analyzing the effect of early diagnosis to mortality and related outcomes of CCHD treatment.

The annual prevalence of neonatal CCHD in Korea was 0.144% percent. A total of 2,241 CCHD neonates, 1,546 (69.0%) underwent cardiac ultrasound within three days after birth, and mothers of 419 neonates had a record of prenatal fetal ultrasound (18.7%). In our comparison of neonates diagnosed with CCHD within three days of birth with those diagnosed with CCHD on or after day 4 of birth, the probability of early diagnosis increased for preterm infants and infants with low birth rate. Regarding mortality rate, most types of CCHD showed a significantly higher mortality rate in the early diagnosis group.

The reason for the high mortality rate despite a high early diagnosis rate pertains to the high percentage of patients with severe conditions that induce a serious heart rate within three days of birth. More than half of the neonates with CCHD were found to have not undergone a prenatal fetal ultrasound, rendering this an important policy target.