Factors affecting length of stay according to bronchopulmonary dysplasia severity: a nationwide cohort study in Korea

Abstract

Background: Longer hospitalizations for preterm infants with bronchopulmonary dysplasia (BPD) delay developmental outcomes, increase the risk for hospital-acquired complications, and exert a substantial socioeconomic burden. This study aimed to identify factors associated with an extended length of stay (LOS) at different levels of severity of BPD.

Methods: A cohort study was conducted using the Korean Neonatal Network registry of very low birth weight infants with BPD between 2013 and 2017 through retrospective analysis.

Results: A total of 4263 infants were diagnosed with BPD. For mild BPD, infants requiring surgical treatment for patent ductus arteriosus needed a longer LOS [e^{adjusted β coefficients (adj β)} 1.041; 95% confidence interval (CI): 0.01-0.08] and hydrocephalus (e^{adj β} 1.094; 95% CI 0.01-0.17). In moderate BPD, infants administered steroids or with intraventricular hemorrhage required a longer LOS (e^{adj β} 1.041; 95% CI 0.00-0.07 and e^{adj β} 1.271; 95% CI 0.11-0.38, respectively). In severe BPD, infants with comorbidities required a longer LOS: pulmonary hypertension (e^{adj β} 1.174; 95% CI 0.09-0.23), administrated steroid for BPD (e^{adj β} 1.116; 95% CI 0.07-0.14), sepsis (e^{adj β} 1.062; 95% CI 0.01-0.11), patent ductus arteriosus requiring surgical ligation (e^{adj β} 1.041; 95% CI 0.00-0.08), and intraventricular hemorrhage (e^{adj β} 1.016; 95% CI 0.05-0.26). Additionally, the higher the clinical risk index score, the longer the LOS needed for infants in all groups.

Conclusions: The factors affecting LOS differed according to the severity of BPD. Individualized approaches to reducing LOS may be devised using knowledge of the various risk factors affecting LOS by BPD severity.

Keywords: Bronchopulmonary dysplasia; Length of stay; Very low birth weight.

Fig. 1

Flow chart of study population. This presents a flowchart of the inclusion and exclusion criteria of our study. Analyzed data [n = 4263; mild bronchopulmonary dysplasia (BPD) = 2132, moderate BPD = 887, and severe BPD = 1244] were obtained from the Korean Neonatal Network (KNN) Database, 2013–2017. GA gestational age, NICU neonatal intensive care unit, PICU pediatric intensive care unit

Fig. 2

Length of stay according to BPD severity. The length of stay increases with bronchopulmonary dysplasia (BPD) severities: 75.1 ± 21.3 days in the mild BPD group, 84.2 ± 25.5 days in the moderate BPD group, and 111.6 ± 40.3 days in the severe BPD group. ^*P < 0.001