Respiratory syncytial virus (RSV) is a common virus that causes infections of the lungs and respiratory tract, leading to a substantial burden on healthcare systems worldwide. Around 90% of all infants are infected with RSV before the age of 2 years and more than 50% are infected twice before the age of 1 year, with most infants manifesting a mild condition manageable at home; however, a small but significant proportion of these infants need hospitalisation. There are infants known to be at higher risk of severe manifestation of the RSV infection, namely those with chronic lung disease, congenital heart disease, neuromuscular disorders, immunodeficiencies, and preterm birth. Infants born during the RSV season (October to March in England) are also thought to have higher risk of severe manifestation. Without a specific treatment for RSV infection, prevention is the key to reduce the burden of RSV infection.
With the main goal of informing decision makers on the best prevention strategy, this project will estimate secondary care health care resource utilisation (HCRU), and associated primary care HCRU, of RSV admissions in hospitalised infants under 2 years of age. HCRU will be quantified prior to and following the admission, and compared with an appropriate comparator cohort, considering infants born in and before RSV season.
This retrospective cohort study will include a birth cohort of all infants all infants born between 01/03/2015 and 28/02/2017 within the CPRD-HES linked dataset. Infants will be followed until the age of 24 months for the identification of a hospital admission of interest, which includes RSV-specific-coded admissions (cohort 1), bronchiolitis-coded admissions (cohort 2) and any respiratory tract infection (RTI)-coded admissions (cohort 3).
As primary objectives, key patient and clinical characteristics will be described and primary and secondary health care resource utilisation (HCRU) and associated costs will be estimated in the 3 case cohorts and compared with the respective comparator cohort (all included infants who did not have any hospital admission of interest according to the respective case cohort definition). HCRU will be assessed in the month prior to and in the 10-<24 months after the first hospital admission of interest. For infants with no admission of interest, an equivalent period will be estimated.
As secondary objectives, the patient pathway will be described, including chronological mapping of a) primary and secondary care elective and non-elective consultations, and b) treatment pathway, including procedures, in the 3 case cohorts.
To overcome the infrequent use of RSV-specific codes and to have a more comprehensive approach, additional exploratory objectives are defined. The first is to define a complementary RSV-predicted case cohort based on a published algorithm, and answer all primary and secondary objectives for this cohort. The second is to estimate the total national burden of RSV-associated General Practitioner (GP) consultations, and total national burden of RSV-associated hospitalisations in hospitalised cases only using multiple linear regression modelling, by in/before season birth for infants aged <24 months.
This study focuses on descriptive analyses of patient demographics and clinical characteristics, HCRU, patient pathways, and on model estimation of the total national RSV burden. As such, all of the characteristics described can be considered study outcomes, namely:
Age at first admission; birth month; birth in RSV season; sex; birth weight; birth length; BMI; index of multiple deprivation; region; ethnicity; comorbidities (Chronic Lung Disease; Congenital heart disease; Prematurity; Neurological disorders; Immunodeficiency); high-risk status; calendar week of admission of interest; concomitant medications; procedures; providers; intensive care unit (ICU) usage; number of GP consultations; cost of GP consultations; number of inpatient hospitalisations; number of outpatient visits; number of Accident & Emergency (A&E) visits; total cost of secondary care visits; total cost of primary and secondary care visits; hospital length of stay; mortality.
Caroline O'Leary - Chief Investigator - IQVIA Ltd ( UK )
Maria João Fonseca - Corresponding Applicant - IQVIA Ltd ( UK )
Fiona Ingleby - Collaborator - IQVIA Ltd ( UK )
Jessica Lundbom - Collaborator - IQVIA Ltd ( UK )
Lawrence Farrell - Collaborator - IQVIA Ltd ( UK )
Lorena Cirneanu - Collaborator - IQVIA Ltd ( UK )
Rachel Reeves - Collaborator - IQVIA Ltd ( UK )
Fiona Ingleby - Collaborator - IQVIA Ltd ( UK )
Florence Brellier - Collaborator - IQVIA Ltd ( UK )
Harveen Ubhi - Collaborator - IQVIA Ltd ( UK )
Jessica Lundbom - Collaborator - IQVIA Ltd ( UK )
HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;Patient Level Index of Multiple Deprivation