Clinical epidemiology and disease burden of bronchiolitis in hospitalized children in China: a national cross-sectional study

Abstract

Background: Bronchiolitis is a common acute lower respiratory tract infection (ALRTI) and the most frequent cause of hospitalization of infants and young children with ALRTI. Respiratory syncytial virus is the main pathogen that leads to severe bronchiolitis. The disease burden is relatively high. To date, few descriptions of the clinical epidemiology and disease burden of children hospitalized for bronchiolitis are available. This study reports the general clinical epidemiological characteristics and disease burden of bronchiolitis in hospitalized children in China.

Methods: This study included the face sheet of discharge medical records collected from 27 tertiary children's hospitals from January 2016 to December 2020 that were aggregated into the FUTang Update medical REcords (FUTURE) database. The sociodemographic variables, length of stay (LOS) and disease burden of children with bronchiolitis were analyzed and compared using appropriate statistical tests.

Results: In total, 42,928 children aged 0-3 years were hospitalized due to bronchiolitis from January 2016 to December 2020, accounting for 1.5% of the total number of hospitalized children of the same age in the database during the period and 5.31% of the hospitalizations for ALRTI. The male to female ratio was 2.01:1. Meanwhile, more boys than girls were observed in different regions, age groups, years, and residences. The 1-2 year age group had the greatest number of hospitalizations for bronchiolitis, while the 29 days-6 months group had the largest proportion of the total inpatients and inpatients with ALRTI in the same age group. In terms of region, the hospitalization rate of bronchiolitis was the highest in East China. Overall, the number of hospitalizations from 2017 to 2020 showed a decreasing trend from that in 2016. Seasonally, the peak hospitalizations for bronchiolitis occurred in winter. Hospitalization rates in North China in autumn and winter were higher than those in South China, while hospitalization rates in South China were higher in spring and summer. Approximately, half of the patients with bronchiolitis had no complications. Among the complications, myocardial injury, abnormal liver function and diarrhea were more common. The median LOS was 6 days [interquartile range (IQR) = 5-8], and the median hospitalization cost was 758 United States dollars (IQR = 601.96-1029.53).

Conclusions: Bronchiolitis is a common respiratory disease in infants and young children in China, and it accounts for a higher proportion of both total hospitalizations and hospitalizations due to ALRTI in children. Among them, children aged 29 days-2 years are the main hospitalized population, and the hospitalization rate of boys is significantly higher than that of girls. The peak season for bronchiolitis is winter. Bronchiolitis causes few complications and has a low mortality rate, but the burden of this disease is heavy.

Keywords: Bronchiolitis; Children; Clinical epidemiology; Disease burden; Respiratory syncytial virus.

Fig. 1

Sex ratios of children hospitalized with bronchiolitis. Sex ratios in different regions (a), age groups (b), years (c), and residences (d)

Fig. 2

Proportion of hospitalizations for bronchiolitis in different months

Fig. 3

The proportion of hospitalizations for bronchiolitis among the total number of hospitalizations in different age groups (a), regions (b), years (c) and months (d)

Fig. 4

Proportion of bronchiolitis hospitalizations to ALRTI hospitalizations in different age groups (a), regions (b), years (c) and months (d). ALRTI acute lower respiratory tract infection

Fig. 5

Number and proportion of children hospitalized with bronchiolitis from January 2016 to December 2020. M month, Y year

Fig. 6

Proportion of hospitalizations for bronchiolitis by month in southern and northern China

Fig. 7

Complications and comorbidities of bronchiolitis. Overview of complications in children hospitalized with bronchiolitis (a) and the distribution of bronchiolitis-related complications (b)

Fig. 8

Length of stay (LOS) and hospitalization expenses for a range of complications. LOS for different complications (a) and hospitalization expenses for different complications (b)