Burden of Respiratory Syncytial Virus (RSV) in Children in Sweden (BRICS): A Retrospective Study in Sweden

May 13, 2024 updated by: Sanofi Pasteur, a Sanofi Company

Primary Objective:

-Estimate the hospital-associated healthcare resource use (HCRU), and associated costs, of RSV infection in children in comparison to the non-RSV control cohort (general population) and patients with rhinovirus infection.

Secondary Objectives:

  • Describe demographic and clinical patient characteristics of RSV infected children.
  • Estimate and compare the incidence of RSV infection and acute respiratory infections (ARIs) in children.
  • Estimate the mortality associated with RSV infection in children.
  • Estimate the social economic burden of RSV infection in children in relation to parents staying home from work to care for their sick child (VAB leave) in comparison to non-RSV control cohort (i.e. parents to children in the general population).

    • Estimate the net days with VAB leave and the compensation disbursed (temporary parental benefit) associated with RSV infection in children.
    • Estimate the indirect costs that can be attributed to VAB leave.
  • Examine the medium- and long-term complications associated with an RSV diagnosis in children in comparison to the non-RSV control chart (general population) and patients with rhinovirus infection.
  • Examine and describe risk factors associated with an RSV infection in children
  • Estimate the healthcare resource use (HCRU), and associated costs, of RSV infection in children, for a subset of patients where primary care data is available, in comparison to the non-RSV control cohort (general population).

Study Overview

Status

Completed

Conditions

Detailed Description

The overall study period will be between July 1st 2001 and to latest available date (likely June 30th 2022).

Patients will be identified for inclusion in the study population between July 1st 2006 and June 30th 2021.

Patients will be followed from time of inclusion until end of the study period or until death.

All patients will have an index date corresponding to the date of diagnosis of incident infection in primary and/or hospital care during the identification period. An incident infection is defined as the occurrence of infections more than 30 (>30) days apart. This implies that a patient can have more than one index date during the study period. Patients that are included in both the RSV cohort and the regional primary care RSV cohort may have two different index dates for the same incident infection, depending on the objective. This is if a patient is first treated in primary care and then hospitalized. The index date is defined differently for the two cohorts, as the first diagnosis in hospital care for the RSV cohort and first diagnosis in primary care OR hospital care for the regional primary care cohort. The non-RSV controls will have the same index date as their matched RSV patient.

The look-back period will be used to inform baseline characteristics as well as patients' medical and diagnosis history. All patients will have possible look-back from birth for information on the patient's hospital care history and from 2005 for information on the patient's prescribed drugs history. The individual look-back and follow-up will depend on the time of inclusion in the study population as well as age at inclusion.

Study Type

Observational

Enrollment (Actual)

1100000

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

No older than 5 years (Child)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The source population for this study will consist of all children (≤5 years of age) in Sweden with an RSV infection or any acute respiratory infection (ARI) between January 1rst 2001 and latest available date, identified from three sources:

  • Primary or secondary diagnosis in hospital care (National Patient Registry)
  • Primary or secondary diagnosis in primary care (regional databases)
  • Positive RSV laboratory test result (Regional laboratory data) The expected study sample is 38,000 unique pediatric patients with an RSV diagnosis, identified in the National Patient Register between 2001 and 2020. The expected RSV sample size, the non-RSV control population will consist of 80,000-160,000 individuals, matched 1:10. The expected number of ARI infections during the time period is estimated to around 1 million. This totals a study sample of between 1-1.1 million.

Description

Inclusion Criteria:

•Children (≤5 years of age) with an RSV infection or any acute respiratory infection (ARI) between July 1st 2001 and latest available date, identified in either hospital care, regional primary care or laboratory database.

Exclusion Criteria:

•There are no exclusion criteria for this study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Retrospective

Cohorts and Interventions

Group / Cohort
RSV cohort
Children (<5 years of age at diagnosis) with a diagnosis of RSV (ICD-10 code) in hospital care between July 1st 2006 and June 30th 2021
Regional primary care RSV cohort
Children (<5 year of age) with a diagnosis of RSV (ICD-10 code) in primary care identified in regional databases (Region Skåne, Region Halland and VGR) between July 1st 2006 and June 30th 2021
Regional laboratory RSV cohort
Children (<5 years of age) with a positive laboratory RSV test result (multiplex/rapid PCR, antigen, immunofluorescence or immunochromatography rapid test) in primary or hospital care, identified in regional laboratory databases (Region Skåne and Region Halland) between July 1st 2006 and June 30th 2021
Acute Respiratory Infections (ARI) cohort
Children (<5 of age) with a diagnosis of ARI (ICD-10 code,) in hospital care between July 1st 2006 and June 30th 2021
Regional ARI cohort
Children (<5 years of age) with a diagnosis of RSV (ICD-10 code, see Table 1) in primary care, identified in regional databases (Region Skåne, Region Halland and VGR)
Rhinovirus cohort
Children (<5 of age) with a diagnosis of rhinovirus (ICD-10 code,) in hospital care between July 1st 2006 and June 30th 2021
Human Metapneumovirus (HMPV) cohort
Children (<5 of age) with a diagnosis of HMPV (ICD-10 code,) in hospital care between July 1st 2006 and June 30th 2021
Parainfluenza cohort
Children (<5 of age) with a diagnosis of parainfluenza (ICD-10 code,) in hospital care between July 1st 2006 and June 30th 2021
Parent cohort
Parents to all children will be linked to the study population, which is possible through linkage between children and parents by their personal identifiers
Non-RSV control cohort
A non-RSV control population consisting of children (<5 years of age) will be extracted to estimate the burden compared to the general population

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Short-term healthcare: Number of specialist outpatient visits
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Number of RSV specialist outpatient hospital visits during follow-up
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Short-term healthcare: Number of hospitalizations
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Number of hospitalizations/stays related to RSV during follow-up
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Short-term healthcare: Length of hospitalizations
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
The length of hospitalizations/stays related to RSV during follow-up
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Short-term healthcare: Number of Intensive Care Unit (ICU) hospitalizations
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Number of ICU hospitalizations/stays related to RSV during follow-up
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Short-term healthcare: Length of ICU hospitalizations
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
The length of ICU hospitalizations/stays related to RSV during follow-up
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Short-term healthcare: Number of RSV-related medical/surgical procedures
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Number of RSV-related medical/surgical procedures during follow-up
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Short-term healthcare: Number of dispensed prescriptions of RSV-related medications
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Number of dispensed prescriptions of RSV-related medications during follow-up
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Short-term healthcare: The costs of direct medical (in- and outpatient care)
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Direct medical (in- and outpatient care) costs related to RSV infection
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Short-term healthcare: The costs of RSV-related medications
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
The costs of dispensed prescriptions of RSV-related medications based on pharmacy retail price
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Medium-term healthcare: Number of specialist outpatient visits
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Number of RSV specialist outpatient hospital visits during follow-up
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Medium-term healthcare: Number of hospitalizations
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Number of hospitalizations/stays related to RSV during follow up
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Medium-term healthcare: Length of hospitalizations
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
The length of hospitalizations/stays related to RSV during follow up
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Medium-term healthcare: Number of Intensive Care Unit (ICU) hospitalizations
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Number of ICU hospitalizations/stays related to RSV during follow-up
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Medium-term healthcare: Length of ICU hospitalizations
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
The length of ICU hospitalizations/stays related to RSV during follow-up
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Medium-term healthcare: Number of RSV-related medical/surgical procedures
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Number of RSV-related medical/surgical procedures during follow-up
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Medium-term healthcare: Number of dispensed prescriptions of RSV-related medications
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Number of dispensed prescriptions of RSV-related medications during follow-up
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Medium-term healthcare: The costs of direct medical (in- and outpatient care)
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Direct medical (in- and outpatient care) costs related to RSV infection
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Medium-term healthcare: The costs of RSV-related medications
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
The costs of dispensed prescriptions of RSV-related medications based on pharmacy retail price
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Patient characteristics
Time Frame: Analysis period: July 1st 2006 - June 30th 2021 Reporting period: at index date or during look-back period
Age at diagnosis, sex distribution, region of residence, birth weight, birth height, gestational age, mothers age at birth, high-risk conditions, parent's education, parent's income, household status
Analysis period: July 1st 2006 - June 30th 2021 Reporting period: at index date or during look-back period
Incidence of RSV/ARIs
Time Frame: Analysis period: July 1st 2006 - June 30th 2021 Reporting period: by respiratory years
Incidence of RSV/ARI per 100,000 population
Analysis period: July 1st 2006 - June 30th 2021 Reporting period: by respiratory years
Number of laboratory-confirmed RSV cases with RSV diagnosis
Time Frame: Analysis period: July 1st 2006 - June 30th 2021 Reporting period: at index date or during look-back period
Number of laboratory confirmed RSV cases with RSV diagnosis code (ICD-10)
Analysis period: July 1st 2006 - June 30th 2021 Reporting period: at index date or during look-back period
Number of laboratory-confirmed RSV cases with no RSV diagnosis
Time Frame: Analysis period: July 1st 2006 - June 30th 2021Reporting period: at index date or during look-back period
Number of laboratory confirmed RSV cases with no RSV diagnosis code (ICD-10)
Analysis period: July 1st 2006 - June 30th 2021Reporting period: at index date or during look-back period
Number of diagnosed RSV cases with no RSV laboratory tests conducted
Time Frame: Analysis period: July 1st 2006 - June 30th 2021 Reporting period: at index date or during look-back period
Number of diagnosed RSV cases (ICD-10) with no laboratory test conducted
Analysis period: July 1st 2006 - June 30th 2021 Reporting period: at index date or during look-back period
Mortality
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
All-cause 30-day death from index date
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 30 days from index date
Socioeconomic burden: Net days of VAB leave
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Net days of temporary parental leave (VAB) during follow-up period due to child with RSV diagnosis
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Socioeconomic burden: Net VAB leave benefit
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Net temporary parental leave (VAB) benefit during follow-up period due to child with RSV diagnosis
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Socioeconomic burden: Indirect costs of VAB leave due to RSV
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Productivity loss due to RSV-related temporary parental leave during follow-up period, calculated by human capital method and average wage
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: 12 months from (first) index date
Proportion of patients that develop respiratory complications (ICD-10 codes)
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: per year during 5 years from index date
Proportion of patients that develop respiratory complications (ICD-10 codes)
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: per year during 5 years from index date
Incidence of RSV per 1000 person-years
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: per year during 5 years from index date
Incidence of RSV per 1000 person-years in RSV, non-RSV control cohorts and rhinovirus cohorts
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: per year during 5 years from index date
Incidence rate ratios (IRR)
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: per year during 5 years from index date
Incidence rate ratios (IRR) in RSV, non-RSV control and rhinovirus cohorts
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: per year during 5 years from index date
Hazard ratios (HR)
Time Frame: Analysis period: July 1st 2006 - July 31st 2021 Reporting period: per year during 5 years from index date
Hazard ratios (HR) in RSV, non-RSV control and rhinovirus cohorts
Analysis period: July 1st 2006 - July 31st 2021 Reporting period: per year during 5 years from index date
Estimation of hazard ratio of each risk factor on being diagnosed with RSV
Time Frame: Analysis period: July 1st 2006 - July 31st 2021Reporting period: look back period
A Cox proportional hazards regression model will be used to estimate the hazard ratio of each risk factor on being diagnosed with RSV. Predictors for RSV diagnosis presented as hazard ratios, including premature birth, high-risk conditions, APGAR, seasonality, mother's age at birth, number of children in household, birth order, parent's education, parent's income, household status, maternal smoking, mother's BMI
Analysis period: July 1st 2006 - July 31st 2021Reporting period: look back period
Primary Care: Number of primary care contacts
Time Frame: Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Number of primary care contacts during follow-up period
Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Primary Care: Number of specialized outpatient care visits
Time Frame: Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Number of specialized outpatient care visits during follow-up period
Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Primary Care: Number of hospitalizations
Time Frame: Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Number of hospitalizations/stays related to RSV during follow-up
Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Primary Care: Length of hospitalizations
Time Frame: Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Length of hospitalizations/stays related to RSV during follow-up
Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Primary Care: Number of ICU hospitalizations
Time Frame: Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Number of ICU hospitalizations/stays related to RSV during follow-up
Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Primary Care: Length of ICU hospitalizations
Time Frame: Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Length of ICU hospitalizations/stays related to RSV during follow-up
Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Primary Care: Number of RSV-related medical/surgical procedures
Time Frame: Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Number of RSV-related medical/surgical procedures during follow-up
Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Primary Care: Number of dispensed prescriptions of RSV-related medications
Time Frame: Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Number of dispensed prescriptions of RSV-related medications during follow-up
Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Primary Care: The costs of direct medical (in- and outpatient care)
Time Frame: Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Direct medical (in- and outpatient care) costs related to RSV infection
Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
Primary Care: The costs of RSV-related medications
Time Frame: Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date
The costs of dispensed prescriptions of RSV-related medications based on pharmacy retail price
Analysis period: Date of first available data - July 31st 2021 Reporting period: 30 days from index date

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Collaborators

Investigators

  • Study Director: Clinical Sciences & Operations, Sanofi

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 1, 2006

Primary Completion (Actual)

April 19, 2024

Study Completion (Actual)

April 19, 2024

Study Registration Dates

First Submitted

October 28, 2022

First Submitted That Met QC Criteria

November 10, 2022

First Posted (Actual)

November 18, 2022

Study Record Updates

Last Update Posted (Actual)

May 14, 2024

Last Update Submitted That Met QC Criteria

May 13, 2024

Last Verified

May 1, 2024

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • RSV00046
  • U1111-1280-4878 (Registry Identifier: ICTRP)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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