OUP accepted manuscript

Epidemiology of Medically Attended Respiratory Syncytial Virus Lower Respiratory Tract Infection in Japanese Children, 2011-2017

BACKGROUND

The objective was to report critical respiratory syncytial virus (RSV)-related epidemiological and healthcare resource utilization measures among Japanese children stratified by gestational and chronological age groups.

METHODS

The JMDC (formerly the Japan Medical Data Center) was used to retrospectively identify infants with or without RSV infection (beginning between 1 February 2011 and 31 January 2016, with follow-up through 31 December 2017). The incidence of RSV medically attended lower respiratory tract infection (MALRI) was captured by flagging hospitalizations, outpatient, and emergency department/urgent care visits with an RSV diagnosis code during the season.

RESULTS

Of 113 529 infants and children identified, 17 022 (15%) had an RSV MALRI (14 590 during the season). The RSV MALRI and hospitalization rates in the first 5 months were 14.3/100 child-years (CY) and 6.0/100 CY, respectively (13.4/100 and 5.8/100 CY for full-term infants and 20/100 and 6.8/100 CY for late preterm infants, respectively). Among those with ≥1 type of MALRI event during the RSV season, >80% of children had it by 24 months of chronological age, although this observation differed by prematurity status. Sixty percent of healthcare resource utilization measures started in the outpatient setting.

CONCLUSIONS

This study emphasizes the RSV burden in young children and critically highlights the data needed to make decisions about new preventive strategies.

Healthcare Utilization Among Infants Covered by Medicaid and Newly Diagnosed With Respiratory Syncytial Virus

Background

Infants covered by Medicaid have higher respiratory syncytial virus (RSV) hospitalization rates than those with commercial insurance, but findings are limited to the inpatient setting. This birth cohort study describes healthcare encounters for RSV across all settings among infants covered by Medicaid and the Children's Health Insurance Program.

Methods

Medicaid claims for infants born and residing in Arizona (AZ), California (CA), Florida (FL), Michigan (MI), North Carolina (NC), New York (NY), and Texas (TX) were analyzed for first diagnosis of RSV in 2016-2018 using International Classification of Diseases, Tenth Revision codes. Encounters on the day of first diagnosis were examined by setting in 7 states and by setting and race in CA, FL, and NC.

Results

A total of 80 945 infants were diagnosed with RSV in 7 states in 2016-2018. The highest encounter rates for first RSV diagnosis were in the emergency department (ED) in 5 states (11.0-33.4 per 1000 in AZ, CA, FL, MI, and NY) and outpatient setting in 2 states (54.8 and 68.5 per 1000 in TX and NC). Significantly higher outpatient encounter rates were found in CA and NC for White infants compared to non-White infants. In NC, ED encounter rates were significantly higher for non-White infants than White infants, whereas in CA, the rates were comparable. In these 2 states, hospitalization rates were similar across groups. In FL, compared with White infants, non-White infants had significantly higher encounter rates in each setting on the day of first RSV diagnosis.

Conclusions

This is the first study to describe the burden of RSV by setting and race. Medicaid infants who are newly diagnosed with RSV have the highest burden in ED and outpatient settings.

Medical Costs of Respiratory Syncytial Virus-Associated Hospitalizations and Emergency Department Visits in Children Aged Younger Than 5 Years: Observational Findings from the New Vaccine Surveillance Network, 2016-2019

OBJECTIVE

To assess medical costs of hospitalizations and emergency department (ED) care associated with respiratory syncytial virus (RSV) disease in children enrolled in the New Vaccine Surveillance Network.

STUDY DESIGN

We used accounting and prospective surveillance data from 6 pediatric health systems to assess direct medical costs from laboratory-confirmed RSV-associated hospitalizations (n = 2007) and ED visits (n = 1267) from 2016 through 2019 among children aged <5 years. We grouped costs into categories relevant to clinical care and administrative billing practices. We examined RSV-associated medical costs by care setting using descriptive and bivariate analyses. We assessed associations between known RSV risk factors and hospitalization costs and length of stay using χ2 tests of association.

RESULTS

The median cost was $7100 (IQR $4006-$13 355) per hospitalized child and $503 (IQR $387-$930) per ED visit. Eighty percent (n = 2628) of our final sample were children aged younger than 2 years. Fewer weeks' gestational age was associated with greater median costs in hospitalized children (P < .001, ≥37 weeks of gestational age: $6840 [$3905-$12 450]; 29-36 weeks of gestational age: $7721 [$4362-$15 274]; <29 weeks of gestational age: $9131 [$4518-$19 924]). Infants born full term accounted for 70% of the total expenditures in our sample. Almost three quarters of the health care dollars spent originated in children younger than 12 months of age, the primary age group targeted by recommended RSV prophylactics.

CONCLUSIONS

Reducing the cost burden for RSV-associated medical care in young children will require prevention of RSV in all young children, not just high-risk infants. Newly available maternal vaccine and immunoprophylaxis products could substantially reduce RSV-associated medical costs.

Burden of disease of respiratory syncytial virus in infants, young children and pregnant women and people

Background

Passive immunization products for infants and pregnant women and people have sparked interest in understanding Canada's respiratory syncytial virus (RSV) burden. This rapid review examines RSV burden of disease in infants, young children and pregnant women and people.

Methods

Electronic databases were searched to identify studies and systematic reviews reporting data on outpatient visits, hospitalizations, intensive care unit admissions, deaths and preterm labour associated with RSV. We also contacted Canadian respiratory virus surveillance experts for additional data.

Results

Overall, 17 studies on infants and young children and 10 studies on pregnant women and people were included, in addition to primary surveillance data from one Canadian territory (Yukon). There were higher rates of medical utilization for infants than older children. Hospitalization rates were highest in infants under six months (more than 1% annually), with 5% needing intensive care unit admission, but mortality was low. Severe outcomes often occurred in healthy full-term infants and burden was higher than influenza. Respiratory syncytial virus attack rate was 10%-13% among pregnant women and people. Only one study found a higher hospitalization rate in pregnant women and people compared to non-pregnant women and people. Limited evidence was found on intensive care unit admission, death and preterm birth for pregnant women and people.

Conclusion

While risk of severe outcomes is larger in high-risk infants and children, healthcare burden is greatest in healthy term infants. The RSV severity for pregnant women and people appears to be similar to that for non-pregnant women and people.

Multi-faceted analysis and prediction for the outbreak of pediatric respiratory syncytial virus

OBJECTIVES

Respiratory syncytial virus (RSV) is a significant cause of pediatric hospitalizations. This article aims to utilize multisource data and leverage the tensor methods to uncover distinct RSV geographic clusters and develop an accurate RSV prediction model for future seasons.

MATERIALS AND METHODS

This study utilizes 5-year RSV data from sources, including medical claims, CDC surveillance data, and Google search trends. We conduct spatiotemporal tensor analysis and prediction for pediatric RSV in the United States by designing (i) a nonnegative tensor factorization model for pediatric RSV diseases and location clustering; (ii) and a recurrent neural network tensor regression model for county-level trend prediction using the disease and location features.

RESULTS

We identify a clustering hierarchy of pediatric diseases: Three common geographic clusters of RSV outbreaks were identified from independent sources, showing an annual RSV trend shifting across different US regions, from the South and Southeast regions to the Central and Northeast regions and then to the West and Northwest regions, while precipitation and temperature were found as correlative factors with the coefficient of determination R2≈0.5, respectively. Our regression model accurately predicted the 2022-2023 RSV season at the county level, achieving R2≈0.3 mean absolute error MAE < 0.4 and a Pearson correlation greater than 0.75, which significantly outperforms the baselines with P-values <.05.

CONCLUSION

Our proposed framework provides a thorough analysis of RSV disease in the United States, which enables healthcare providers to better prepare for potential outbreaks, anticipate increased demand for services and supplies, and save more lives with timely interventions.

Systematic Literature Review of Respiratory Syncytial Virus Laboratory Testing Practices and Incidence in United States Infants and Children <5 Years of Age

Background

Respiratory syncytial virus (RSV) can cause serious illness in those aged <5 years in the United States, but uncertainty remains around which populations receive RSV testing. We conducted a systematic literature review of RSV testing patterns in studies published from 2000 to 2021.

Methods

Studies of RSV, medically attended RSV lower respiratory tract infections (LRTIs), and bronchiolitis were identified using standard methodology. Outcomes were clinical decisions to test for RSV, testing frequency, and testing incidence proportions in inpatient (IP), emergency department (ED), outpatient (OP), and urgent care settings.

Results

Eighty good-/fair-quality studies, which reported data from the period 1988–2020, were identified. Twenty-seven described the clinical decision to test, which varied across and within settings. Two studies reported RSV testing frequency for multiple settings, with higher testing proportions in IP (n = 2, range: 83%–85%, 1996–2009) compared with ED (n = 1, 25%, 2006–2009) and OP (n = 2, 15%–25%, 1996–2009). Higher RSV testing incidence proportions were observed among LRTI infant populations in the ED (n = 1, 74%, 2007–2008) and OP (n = 2, 54%–69%, 1995–2008). Incidence proportions in LRTI populations were not consistently higher in the IP setting (n = 13). Across studies and time, there was heterogeneity in RSV testing patterns, which may reflect varying detection methods, populations, locations, time periods, and healthcare settings.

Conclusions

Not all infants and children with LRTI are tested for RSV, highlighting underestimation of RSV burden across all settings.

OUP accepted manuscript

Background

Respiratory syncytial virus (RSV) is the leading cause of hospitalizations in United States infants aged <1 year, but research has focused on select populations.

Methods

National (Nationwide) Inpatient Sample and National Emergency Department (ED) Sample data (2011–2019) were used to report RSV hospitalization (RSVH), bronchiolitis hospitalization (BH), and ED visit counts, percentage of total hospitalizations/visits, and rates per 1000 live births along with inpatient mortality, mechanical ventilation (MV), and total charges (2020 US dollars).

Results

Average annual RSVH and RSV ED visits were 56 927 (range, 43 845–66 155) and 131 999 (range, 89 809–177 680), respectively. RSVH rates remained constant over time (P = .5), whereas ED visit rates increased (P = .004). From 2011 through 2019, Medicaid infants had the highest average rates (RSVH: 22.3 [95% confidence interval {CI}, 21.5–23.1] per 1000; ED visits: 55.9 [95% CI, 52.4–59.4] per 1000) compared to infants with private or other/unknown insurance (RSVH: P < .0001; ED visits: P < .0001). From 2011 through 2019, for all races and ethnicities, Medicaid infants had higher average RSVH rates (up to 7 times) compared to infants with private or other/unknown insurance. RSVH mortality remained constant over time (P = .8), whereas MV use (2019: 13% of RSVH, P < .0001) and mean charge during hospitalization (2019: $21 513, P < .0001) increased. Bronchiolitis patterns were similar.

Conclusions

This study highlights the importance of ensuring access to RSV preventive measures for all infants.

OUP accepted manuscript

Background

This study describes leading causes of hospitalization, including respiratory syncytial virus (RSV), in United States infants (<1 year) from 2009 through 2019.

Methods

Within the National (Nationwide) Inpatient Sample (NIS) data, hospitalizations were determined by primary diagnosis using International Classification of Diseases, Ninth or Tenth Revision codes. RSV was defined as 079.6, 466.11, 480.1, B97.4, J12.1, J20.5, or J21.0. Bronchiolitis was defined as 466.19, J21.8, or J21.9. Leading causes overall and by sociodemographic variables were identified. The Kids’ Inpatient Database (KID) was used for confirmatory analyses.

Results

Acute bronchiolitis due to RSV (code 466.11 or J21.0) was the leading primary diagnosis, accounting for 9.6% (95% confidence interval [CI], 9.4%–9.9%) and 9.3% (95% CI, 9.0%–9.6%) of total infant hospitalizations from January 2009 through September 2015 and October 2015 through December 2019, respectively; it was the leading primary diagnosis in every year accounting for >10% of total infant hospitalizations from December through March, reaching >15% in January–February. From 2009 through 2011, acute bronchiolitis due to RSV was the leading primary diagnosis in every birth month. Acute bronchiolitis due to RSV was the leading cause among all races/ethnicities, except Asian/Pacific Islanders, and all insurance payer groups. KID analyses confirmed these results.

Conclusions

Acute bronchiolitis due to RSV is the leading cause of US infant hospitalizations.