Bronchiolitis Hospitalization Rates Research Articles

A Systematic Literature Review of the Burden of Respiratory Syncytial Virus and Health Care Utilization Among United States Infants Younger Than 1 Year.

BackgroundThe burden and health care utilization (HCU) of respiratory syncytial virus (RSV) in US infants aged <1 year across health care settings are not well characterized.MethodsWe systematically reviewed studies of RSV and bronchiolitis published 2000–2021 (data years, 1979–2020). Outcomes included RSV hospitalization (RSVH)/bronchiolitis hospitalization rates, emergency department (ED)/outpatient (OP) visit rates, and intensive care unit (ICU) admissions or mechanical ventilation (MV) use among RSV-/bronchiolitis-hospitalized infants. Study quality was determined using standard tools.ResultsWe identified 141 good-/fair-quality studies. Five national studies reported annual average RSVH rates (range, 11.6 per 1000 per year among infants aged 6–11 months in 2006 to 50.1 per 1000 per year among infants aged 0–2 months in 1997). Two national studies provided RSVH rates by primary diagnosis for the entire study period (range, 22.0–22.7 per 1000 in 1997–1999 and 1997–2000, respectively). No national ED/OP data were available. Among 11 nonnational studies, RSVH rates varied due to differences in time, populations (eg, prematurity), and locations. One national study reported that RSVH infants with high-risk comorbidities had 5-times more MV use compared to non–high-risk infants in 1997-2012.ConclusionsSubstantial data variability was observed. Nationally representative studies are needed to elucidate RSV burden and HCU.

Essentials in saline pharmacology for nasal or respiratory hygiene in times of COVID-19

Purpose: Nasal irrigation or nebulizing aerosol of isotonic or hypertonic saline is a traditional method for respiratory or nasal care. A recent small study in outpatients with COVID-19 without acute respiratory distress syndrome suggests substantial symptom resolution. We therefore analyzed pharmacological/pharmacodynamic effects of isotonic or hypertonic saline, relevant to SARS- CoV-2 infection and respiratory care. Methods: Mixed search method. Results: Due to its wetting properties, saline achieves an improved spreading of alveolar lining fluid and has been shown to reduce bio-aerosols and viral load. Saline provides moisture to respiratory epithelia and gels mucus, promotes ciliary beating, and improves mucociliary clearance. Coronaviruses and SARS-CoV-2 damage ciliated epithelium in the nose and airways. Saline inhibits SARS- CoV-2 replication in Vero cells; possible interactions involve the viral ACE2-entry mechanism (chloride-dependent ACE2 configuration), furin and 3CLpro (inhibition by NaCl), and the sodium channel ENaC. Saline shifts myeloperoxidase activity in epithelial or phagocytic cells to produce hypochlorous acid. Clinically, nasal or respiratory airway care with saline reduces symptoms of seasonal coronaviruses and other common cold viruses. Its use as aerosol reduces hospitalization rates for bronchiolitis in children. Preliminary data suggest symptom reduction in symptomatic COVID-19 patients if saline is initiated within 48 h of symptom onset. Conclusions: Saline interacts at various levels relevant to nasal or respiratory hygiene (nasal irrigation, gargling or aerosol). If used from the onset of common cold symptoms, it may represent a useful add-on to first-line interventions for COVID-19. Formal evaluation in mild COVID-19 is desirable as to establish efficacy and optimal treatment regimens.

Risk factors for bronchiolitis hospitalization in infants: AFrench nationwide retrospective cohort study over four consecutive seasons (2009-2013).

ObjectivesLarge studies are needed to update risk factors of bronchiolitis hospitalization. We performed a nationwide analysis of hospitalization rates for bronchiolitis over four consecutive bronchiolitis seasons to identify underlying medical disorders at risk of bronchiolitis hospitalization and assess their frequency.MethodsData were retrieved from the French National Hospital Discharge database. Of all infants discharged alive from maternity wards from January 2008 to December 2013 in France (N = 3,884,791), we identified four consecutive cohorts at risk of bronchiolitis during the seasons of 2009–2010 to 2012–2013. The main outcome was bronchiolitis hospitalization during a season. Individual risk factors were collected.ResultsAmong infants, 6.0% were preterm and 2.0% had ≥1 chronic condition including 0.2% bronchopulmonary dysplasia (BPD) and 0.2% hemodynamically significant congenital heart disease (HS-CHD). Bronchiolitis hospitalization rates varied between seasons (min: 1.26% in 2010–2011; max: 1.48% in 2012–2013; p<0.001). Except omphalocele, the following conditions were associated with an increased risk for bronchiolitis hospitalization: solid organ (9.052; 95% CI, 4.664–17.567) and stem cell transplants (6.012; 95% CI, 3.441–10.503), muscular dystrophy (4.002; 95% CI, 3.1095–5.152), cardiomyopathy (3.407; 95% CI, 2.613–4.442), HS-CHD (3.404; 95% CI, 3.153–3.675), congenital lung disease and/or bronchial abnormalities, Down syndrome, congenital tracheoesophageal fistula, diaphragmatic hernia, pulmonary hypertension, chromosomal abnormalities other than Down syndrome, hemodynamically non-significant CHD, congenital abnormalities of nervous system, cystic fibrosis, cleft palate, cardiovascular disease occurring during perinatal period, and BPD.ConclusionBesides prematurity, BPD, and HS–CHD, eighteen underlying conditions were associated with a significant increased risk for bronchiolitis hospitalization in a nationwide population.

Solar radiation, air pollution, and bronchiolitis hospitalizations in Chile: An ecological study.

To evaluate trends and geographic distribution of infant bronchiolitis hospitalizations in Chile, a country with large variation in solar radiation (SR) and high rates of urban air pollution. We performed a nationwide ecological study of bronchiolitis hospitalizations from 2001 to 2014. We investigated the associations of regional SR (a proxy of vitamin D status) and regional fine particulate matter (PM2.5) air pollution with bronchiolitis hospitalizations. We also evaluated the role of sociodemographic factors, including regional poverty, education, indigenous population, and rurality rates. During the study period, 119 479 infants were hospitalized for bronchiolitis in Chile; 59% were boys. The mean bronchiolitis hospitalization rate increased from 29 to 41 per 1000 infants per year (P = .02). There was an inverse correlation between regional SR and incidence of hospital admissions for bronchiolitis (r = -0.52, P = .049), accounting for 27% of these hospitalizations. There was also a significant direct correlation between regional ambient PM2.5 and bronchiolitis hospitalizations (R = 0.68, P = .006), accounting for 42% of the variation in admission rate. High firewood and/or coal residential use for heating, high regional poverty, lower years of education, and high rurality rates were also significantly correlated with bronchiolitis hospitalization rates. None of the environmental or sociodemographic factors evaluated were correlated with regional case fatality rates or length of stay at the hospital. This ecological study revealed significant associations between regional SR, air pollution, and sociodemographic factors with infant bronchiolitis hospitalizations in Chile, suggesting that these factors play a major role in the incidence and severity of respiratory infections in early childhood.

National Bronchiolitis Hospitalization Rates Among Preterm and Full Term Infants: 2010–2015

BackgroundThe 2014 American Academy of Pediatrics (AAP) policy statement on respiratory syncytial virus immunoprophylaxis (RSV IP) recommended against its use in infants 29–34 weeks gestational age (wGA) without chronic lung disease or bronchopulmonary dysplasia (CLD/BPD) or congenital heart disease (CHD). This study examined the impact of these changes by evaluating RSV IP use and bronchiolitis hospitalization rates among full-term (FT) and preterm (PT) infants 29–34 wGA in the 2014–15 RSV season relative to previous seasons.MethodsInfants born 7/1/2009 to 6/30/2015 were identified in the MarketScan Multistate Medicaid (MED) and Commercial (COM) databases; DRG and ICD-9-CM codes were used to select FT and PT infants without CLD/BPD or CHD. Outpatient RSV IP use was identified by drug and administration codes. Bronchiolitis hospitalizations were identified by diagnosis codes (466.11 and 466.19) during the RSV season (Nov–Mar) and summarized by chronologic age (CA). Hospitalization rates were calculated per 100 infant-seasons, and statistical significance was tested using generalized linear regression models with Poisson error, log link, and log offset for exposure time.Results1.1 mil MED and 1.0 mil COM births were identified; 5.2% MED and 4.8% COM infants were born at 29–34 wGA. RSV IP use decreased among MED and COM infants 29–34 wGA (P < .01) in 2014–15 compared with 2013–14. Bronchiolitis hospitalization rates increased for MED and COM infants 29–34 wGA in 2014–15 compared with 2013–14 (rate ratios <3 months CA: MED 1.45, P = .009 and COM 2.1, P = .004; 3–6 months CA: MED 1.35, P = .023 and COM 1.7, P = .053), whereas the rates for FT infants remained the same (rate ratios 0.94–1.08, P > .05). Absolute increases were greatest for infants 29–30 wGA and <3 months CA (MED +10.0 and COM +8.3 per 100 infant-seasons). Similar trends were observed when 2014–15 was compared with the combined 2010–14 RSV seasons.ConclusionIn the 2014–15 RSV season, there was an increase in bronchiolitis hospitalization rates among PT infants born at 29–34 wGA when <3 months and 3–6 months CA, but no increase among FT infants. Trends were consistent in the MED and COM populations and are associated with the change to AAP policy.FundingAstraZenecaDisclosures L. R. Krilov, AstraZeneca/MedImmune: Consultant, Research grant and Research support; J. Fergie, MedImmune: Speaker’s Bureau, Research grant and Research support; M. Goldstein, AstraZeneca/MedImmune: Consultant, Research grant and Research support; K. K. McLaurin, AstraZeneca: Employee, Salary; S. Wade, Truven Health Analytics: Consultant, Consulting fee; D. Diakun, Truven Health Analytics: Employee, Salary; A. Kong, Truven Health Analytics: Employee, Salary

Trends in Respiratory Syncytial Virus and Bronchiolitis Hospitalization Rates in High-Risk Infants in a United States Nationally Representative Database, 1997-2012.

BackgroundRespiratory syncytial virus (RSV) causes significant pediatric morbidity and is the most common cause of bronchiolitis. Bronchiolitis hospitalizations declined among US infants from 2000‒2009; however, rates in infants at high risk for RSV have not been described. This study examined RSV and unspecified bronchiolitis (UB) hospitalization rates from 1997‒2012 among US high-risk infants.MethodsThe Kids’ Inpatient Database (KID) infant annual RSV (ICD-9 079.6, 466.11, 480.1) and UB (ICD-9 466.19, 466.1) hospitalization rates were estimated using weighted counts. Denominators were based on birth hospitalizations with conditions associated with high-risk for RSV: chronic perinatal respiratory disease (chronic lung disease [CLD]); congenital airway anomalies (CAA); congenital heart disease (CHD); Down syndrome (DS); and other genetic, metabolic, musculoskeletal, and immunodeficiency conditions. Preterm infants could not be identified. Hospitalizations were characterized by mechanical ventilation, inpatient mortality, length of stay, and total cost (2015$). Poisson and linear regression were used to test statistical significance of trends.ResultsRSV and UB hospitalization rates were substantially elevated for infants with higher-risk CHD, CLD, CAA and DS without CHD compared with all infants. RSV rates declined by 47.0% in CLD and 49.7% in higher-risk CHD infants; no other declines in high-risk groups were observed. UB rates increased in all high-risk groups except for a 22.5% decrease among higher-risk CHD. Among high-risk infants, mechanical ventilation increased through 2012 to 20.4% and 13.5% of RSV and UB hospitalizations; geometric mean cost increased to $31,742 and $25,962, respectively, and RSV mortality declined to 0.9%.ConclusionsAmong high-risk infants between 1997 and 2012, RSV hospitalization rates declined among CLD and higher-risk CHD infants, coincident with widespread RSV immunoprophylaxis use in these populations. UB hospitalization rates increased in all high-risk groups except higher-risk CHD, suggesting improvement in the health status of higher-risk CHD infants, potentially due to enhanced surgical interventions. Mechanical ventilation use and RSV and UB hospitalization costs increased while RSV mortality declined.

Clarifying Costs and Benefits of Respiratory Syncytial Virus Immunoprophylaxis

In response to recent studies demonstrating that palivizumab use in moderate preterm infants may decrease subsequent wheezing, Meissner and Kimberlin1 discuss costs associated with palivizumab but make multiple statements that may not be consistent with the best available evidence.The stated hospitalization cost of $8530 (2009$) is not representative of respiratory syncytial virus (RSV) hospitalizations among palivizumab-eligible infants; it is the average cost of bronchiolitis hospitalizations among US children <2 years.2 Using the same source, the Kids’ Inpatient Database, the average RSV hospitalization (International Classification of Diseases, Ninth Revision, Clinical Modification 079.6, 466.11, 480.1) cost for all infants was $14 832 (2009$). Among high-risk infants, costs of RSV hospitalization and associated care through 12 months of age range from $20 160 to $39 399 (2010$).3The authors also state the number needed to treat (NNT) with palivizumab to prevent 1 RSV hospitalization for most infants ranges from 19 to 170. In the Canadian Pediatric Society’s RSV prevention position statement, high-quality NNT estimates range from 12 to 23 depending on the population. Lower quality estimates from studies of health care utilization databases, such as those referenced by the authors, often yield higher NNTs due to underdiagnosis of RSV and limited use of RSV-specific codes.Meissner and Kimberlin1 state that RSV hospitalizations are becoming less common among children eligible for palivizumab, citing a 17% decrease in bronchiolitis hospitalization rates from 2000 to 2009 among US children <2 years.2 However, Hasegawa et al2 also found a 34% increase in children with high-risk conditions from 2000 to 2009. According to a personal communication with Dr Hasegawa, the hospitalization rate among children at high risk rose by 29%. This increase despite palivizumab use is not surprising given that most children at high risk do not receive palivizumab and use has declined since 2006.Concerning the cost of palivizumab, the authors state that rebates may modify the cost, but the cost presented does not incorporate rebates. Federally mandated rebates for Medicaid recipients and discounts for 340B-eligible organizations have resulted in ∼40% reduction in palivizumab cost for ∼60% of palivizumab recipients, as described in a recent publication3 and a Centers for Disease Control and Prevention analysis at the June 23, 2010, Advisory Committee on Immunization Practices.Finally, the authors state that mortality reduction cannot be included in palivizumab analyses because it has not been demonstrated in randomized trials. However, mortality reductions are commonly included in cost-effectiveness studies even without statistically significant differences in randomized trials. Two examples include an economic evaluation of pediatric influenza vaccination conducted by the Centers for Disease Control and Prevention and investigators from Harvard University, as well as the UK Health Technology Assessment of palivizumab.4 There is no evidence to support the authors’ statement that “adverse long-term outcomes such as death are not prevented by passive immunotherapy.”Cost-effectiveness analyses of palivizumab should consider all downstream costs and savings and use the best available evidence. As the authors state, quality of life and other factors must be considered. Calculating cost per quality-adjusted life-year gained is the recommended approach to understand the benefits of an intervention relative to costs and enables comparison with other health interventions.5

Hospitalizations for respiratory syncytial virus bronchiolitis in preterm infants at &lt;33 weeks gestation without bronchopulmonary dysplasia: the CASTOR study

This study was conducted during the 2008-2009 respiratory syncytial virus (RSV) season in France to compare hospitalization rates for bronchiolitis (RSV-confirmed and all types) between very preterm infants (<33 weeks' gestational age, WGA) without bronchopulmonary dysplasia and full-term infants (39-41 WGA) matched for date of birth, gender and birth location, and to evaluate the country-specific risk factors for bronchiolitis hospitalization. Data on hospitalizations were collected both retrospectively and prospectively for 498 matched infants (249 per group) aged <6 months at the beginning of the RSV season. Compared to full-term infants, preterm infants had a fourfold [95% confidence interval (CI) 1·36-11·80] and a sevenfold (95% CI 2·79-17·57) higher risk of being hospitalized for bronchiolitis, RSV-confirmed and all types, respectively. Prematurity was the only factor that significantly increased the risk of being hospitalized for bronchiolitis. The risk of multiple hospitalizations for bronchiolitis in the same infant significantly increased with male gender and the presence of siblings aged ⩾2 years.

Severe Bronchiolitis and Respiratory Syncytial Virus Among Young Children in Hawaii

Lower respiratory tract infections are a leading cause of hospitalization and mortality among children worldwide. Our objective was to describe the incidence and epidemiology of severe bronchiolitis, respiratory syncytial virus (RSV), and pneumonia among children in Hawaii. Retrospective analysis of the patient-linked hospital discharge data associated with bronchiolitis, RSV, and pneumonia among Hawaii residents younger than 5 years of age during 1997 through 2004 using the Hawaii State Inpatient Database. During 1997 through 2004, the average annual incidence rates for bronchiolitis, RSV, and pneumonia were 3.8, 2.7, and 6.8 per 1000 children younger than 5 years, respectively. The incidence of each condition was higher for infants younger than 1 year (15.1, 9.8, and 15.9 per 1000 infants, respectively) than the incidence for children 1-4 years of age, and higher for boys compared with girls. The incidence of each condition was highest among Native Hawaiian and other Pacific Islander children compared with children of other race groups living in Hawaii. Most hospitalizations occurred during the months of October through February. Estimated median hospital charges were $4806 (bronchiolitis), $5465 (RSV) and $5240 (pneumonia), with overall average annual charges of $11.5 million. The incidence and hospitalization rates for bronchiolitis, RSV, and pneumonia among children younger than 5 years of age in Hawaii were low; the corresponding hospitalization rates were lower than those for the general U.S. population. However, the hospitalization rates for each condition among Hawaiian and other Pacific Islander children were much higher than those for other race groups or for the U.S. population.

A Case–Crossover Study of Wintertime Ambient Air Pollution and Infant Bronchiolitis

We examined the association of infant bronchiolitis with acute exposure to ambient air pollutants.DesignWe employed a time-stratified case–crossover method and based the exposure windows on a priori, biologically based hypotheses.ParticipantsWe evaluated effects in 19,901 infants in the South Coast Air Basin of California in 1995–2000 with a hospital discharge record for bronchiolitis in the first year of life (International Classification of Diseases, 9th Revision, CM466.1).Evaluations/MeasurementsStudy subjects’ ZIP code was linked to ambient air pollution monitors to derive exposures. We estimated the risk of bronchiolitis hospitalization associated with increases in wintertime ambient air pollutants using conditional logistic regression.ResultsWe observed no increased risk after acute exposure to particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5), carbon monoxide, or nitrogen dioxide. PM2.5 exposure models suggested a 26–41% increased risk in the most premature infants born at gestational ages between 25 and 29 weeks; however, these findings were based on very small numbers.ConclusionsWe found little support for a link between acute increases in ambient air pollution and infant bronchiolitis except modestly increased risk for PM2.5 exposure among infants born very prematurely. In these infants, the periods of viral acquisition and incubation concurred with the time of increased risk.Relevance to Professional PracticeWe present novel data for the infant period and the key respiratory disease of infancy, bronchiolitis. Incompletely explained trends in rising bronchiolitis hospitalization rates and increasing number of infants born prematurely underscore the importance of evaluating the impact of ambient air pollution in this age group in other populations and studies.

Socioeconomic environmental factors and hospitalization for acute bronchiolitis during infancy

Bronchiolitis is a major cause of hospitalization during infancy. The aim of this study was to evaluate the influence of socioeconomic factors on the hospitalization of infants with bronchiolitis. All infants below 1 y of age living in the city of Malmö, Sweden, and hospitalized at the University Hospital, Malmö, owing to bronchiolitis during the years 1998 and 1999 were identified. The bronchiolitis hospitalization rates (BHRs) were determined for the infants living in each of the 10 different administrative residential areas of Malmö and correlated with socio‐economic factors (percentage of immigrants, per capita income, unemployment rate and households receiving social benefit) in the respective residential areas. The severity of the disease on admission and during hospital care was assessed by comparing oxygen saturation, days with supplemental oxygen and length of stay. BHR varied more than fourfold between the 10 residential areas. BHR varied significantly with per capita income and the percentage of immigrants. Infants living in the area with the highest social burden were hospitalized almost twice as often as those from the rest of the city, but the severity of disease was similar. Conclusion: The association between socioeconomic factors and hospitalization indicates that these factors may have a significant influence on the hospitalization rate in bronchiolitis during infancy.

Bronchiolitis-associated hospitalizations among US children, 1980-1996.

Respiratory syncytial virus (RSV) causes more lower respiratory tract infections, often manifested as bronchiolitis, among young children than any other pathogen. Few national estimates exist of the hospitalizations attributable to RSV, and recent advances in prophylaxis warrant an update of these estimates. To describe rates of bronchiolitis-associated hospitalizations and to estimate current hospitalizations associated with RSV infection. Descriptive analysis of US National Hospital Discharge Survey data from 1980 through 1996. Children younger than 5 years who were hospitalized in short-stay, non-federal hospitals for bronchiolitis. Bronchiolitis-associated hospitalization rates by age and year. During the 17-year study period, an estimated 1.65 million hospitalizations for bronchiolitis occurred among children younger than 5 years, accounting for 7.0 million inpatient days. Fifty-seven percent of these hospitalizations occurred among children younger than 6 months and 81 % among those younger than 1 year. Among children younger than 1 year, annual bronchiolitis hospitalization rates increased 2.4-fold, from 12.9 per 1000 in 1980 to 31.2 per 1000 in 1996. During 1988-1996, infant hospitalization rates for bronchiolitis increased significantly (P for trend <.001), while hospitalization rates for lower respiratory tract diseases excluding bronchiolitis did not vary significantly (P for trend = .20). The proportion of hospitalizations for lower respiratory tract illnesses among children younger than 1 year associated with bronchiolitis increased from 22.2% in 1980 to 47.4% in 1996; among total hospitalizations, this proportion increased from 5.4% to 16.4%. Averaging bronchiolitis hospitalizations during 1994-1996 and assuming that RSV was the etiologic agent in 50% to 80% of November through April hospitalizations, an estimated 51, 240 to 81, 985 annual bronchiolitis hospitalizations among children younger than 1 year were related to RSV infection. During 1980-1996, rates of hospitalization of infants with bronchiolitis increased substantially, as did the proportion of total and lower respiratory tract hospitalizations associated with bronchiolitis. Annual bronchiolitis hospitalizations associated with RSV infection among infants may be greater than previous estimates for RSV bronchiolitis and pneumonia hospitalizations combined.