Temporal trend in hospitalization among patients with congenital heart disease in Denmark: a nationwide study

Abstract

Abstract Background The survival rate of patients with congenital heart disease (CHD) had increased over the last decades due to improved management. However, the increased survival rate may potentially impact the number of occurrences of late cardiac complications as well as non-cardiovascular diseases requiring hospitalization, and hence warrants further study on this area. Purpose To delineate the temporal trend in hospitalization rate and length of stay (LOS) among patients with major and minor CHD in Denmark from 1977 to 2018 and to investigate the causes of hospitalization. Methods A Danish nationwide, population-based registry study including patients with CHD diagnosis from 1977 to 2018. Patients were categorized as either major or minor CHD, and by age groups (<1, 1-4, 5-17, 18-39, 40-64, ≥65 years). Hospitalization rate was reported as incidence per 100 person-years. Results In this study, 23,386 patients were included with 121,653 hospital admissions. From 1977-1981 to 2012-2018, the overall all-cause hospitalization rate decreased for both major (51.7 [CI: 48.0 -55.7] to 32.8 [CI: 31.0 - 34.7]) and minor CHD patients (28.4 [CI: 26.0 - 31.0] to 22.6 [CI: 21.1 - 24.1]). Median LOS for major CHD decreased from 5 days (IQR: 2 – 11) to 2 days (IQR: 1 – 6), and for minor CHD from 4 days (IQR: 2 – 8) to 2 days (IQR: 1 – 5). However, the trends when looking at specific age groups were different from the trend of overall all-cause hospitalization rate. Figure 1 shows that hospitalization rate had increased significantly for <1-year-olds for major CHD, whereas an increased trend was observed for <1, 40-64 and ≥65 years-olds for minor CHD. In addition, the trends for specific age groups when looking at the most common causes were also different from the trend of all-cause hospitalization rate. For both major and minor CHD, Table 1 shows that the hospitalization rate for <1-year-olds due to respiratory diseases had increased over time, while the hospitalization rate for 40-64-year-olds due to arrythmia had also increased over time. For ≥65-year-olds, significant increase in hospitalization rate for arrythmia was only observed for minor CHD. Conclusion Lower hospitalization rate for major and minor CHD after 1 year old suggests that early intervention of CHD has improved their morbidity during childhood and early adulthood. However, the increased hospitalization rates among <1 year-olds and the elderly suggest that more focus are needed in preventing non-cardiovascular diseases and late cardiac complications for the respective age groups.Figure 1Table 1