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

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).