The Impact of a History of Pre-maturity on Viral Respiratory Infections in Children Under 2 Years of Age: A Propensity Score-Matching Analysis of in-hospital Complications and Mortality

Introduction: A history of pre-maturity may be a risk factor for complications in patients under 24 months of age hospitalized for viral respiratory infections (VRIs). Objective: To identify the impact of a history of pre-maturity on in-hospital complications and mortality in patients under 24 months of age who were hospitalized for VRIs over a period of 5 years. Material and Methods: This was a propensity score-matched study. The database was compiled by physicians, electronically validated by engineers, and analyzed by statisticians. Patients diagnosed with VRIs (based on International Classification of Diseases [ICD-10]) codes B974, J12, J120–J129X, J168, J17, J171, J178, J20, J203–J209, J21, J210, J211, J218, J219, J22X, and J189) from 2013 to 2017 were enrolled in the study. The subjects were classified into two groups according to the absence or presence of a history of pre-maturity (P070, P072, P073). Patients with congenital heart disease (CHD) (Q20–Q26) were excluded. Length of hospital stay, in-hospital complications, surgical procedures, and mortality were analyzed. Statistical Analysis: Patients were matched according to age. For comparisons between groups, Student's t-tests and chi(2) tests were applied. A logistic regression model was constructed to identify factors related to in-hospital complications and mortality. Results: In total, 5,880 patients were eligible for inclusion in the analysis. The average patient age was 14.25 weeks. The presence of pre-maturity (coefficient = 1.16), male sex, bronchopulmonary dysplasia (BPD), in-hospital infectious complications (coefficient = 11.31), and invasive medical procedures (coefficient = 18.4) increased the number of days of hospitalization. Invasive medical procedures (OR = 6.13), a history of pre-maturity (OR = 2.54), and male sex (OR = 1.78) increased the risk for in-hospital complications. In-hospital infectious complications (OR = 84.2) and invasive medical procedures (OR = 58.4) were risk factors for mortality. Conclusions: A history of pre-maturity increased the length of hospital stay and the rate of in-hospital complications but did not increase mortality in patients under 24 months of age hospitalized for VRIs.