title: Estimates and determinants of economic impacts from influenza-like illnesses caused by respiratory viruses in Australian children attending childcare: a cohort study.
abstract: BACKGROUND
  Influenza and other respiratory infections cause excess winter morbidity in children. This study assessed the economic impact of influenza-like illness (ILI) on families with children attending childcare using a societal perspective.
  
  
  METHODS
  We conducted a prospective cohort study in 90 childcare centres and one general practitioner clinics in Sydney, Australia, during 2010. Healthy children aged ≥6 months to <3 years were enrolled. Economic impacts of ILI (temperature ≥37·8°C or parental report of fever, plus ≥1 respiratory symptoms) were collected at 2 and 4 weeks after ILI onset by telephone interview. Parent-collected respiratory specimens were tested for respiratory viruses using real-time PCR (RT-PCR). Costs associated with healthcare visits, medication usage, carer time lost (work or recreation) and home care and/or additional childcare were collected. Influenza-like illness costs were described and further analysed using a Tobit model. Zero-inflated Poisson regression was employed to compare the numbers of healthcare visits for each ILI.
  
  
  RESULTS
  Of 381 children enrolled and analysed, 105 developed 124 ILIs. Specimens were available for 117 ILIs: five were positive by RT-PCR for A(H1N1)pdm09, 39 for adenovirus, 39 for rhinovirus, 15 for a coronavirus and 27 for a polyomavirus. The mean cost of all ILIs was AU$626 (95% confidence interval: AU$484-768) per ILI with no significant differences observed between viruses. Carers lost on average 13 hours of work and 3 hours of leisure time per ILI. Independent drivers of ILI costs were having both parents in employed work and longer duration of ILI. In multivariate analyses, four variables were significantly associated with an increased number of healthcare visits per ILI: non-Caucasian child, living in a detached house, both parents in employed work and having an ILI with one or more viruses identified.
  
  
  CONCLUSIONS
  For families with a child attending childcare, ILIs cause a substantial economic burden. An ILI in a child with working parents and/or with longer duration appears to cost more in monetary terms. Healthcare visits were increased if the child was non-Caucasian, lived in a detached house, had working parents or had a virus-positive ILI. Our findings on the estimates and determinants of economic impacts from respiratory virus infection highlight the importance and feasibility of an interdisciplinary (epidemiology/health economics) approach to such research.
authors.affiliation: National Centre for Immunisation Research and Surveillance, The Children's Hospital at Westmead, Sydney, NSW, Australia; Discipline of Paediatrics and Child Health, Faculty of Medicine, The University of Sydney, Sydney, NSW, Australia.
authors.forename: Jiehui Kevin
authors.initials: JK
authors.lastname: Yin
authors.forename: Glenn
authors.initials: G
authors.lastname: Salkeld
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Lambert
authors.forename: Alexa
authors.initials: A
authors.lastname: Dierig
authors.forename: Leon
authors.initials: L
authors.lastname: Heron
authors.forename: Julie
authors.initials: J
authors.lastname: Leask
authors.forename: Maria
authors.initials: M
authors.lastname: Yui Kwan Chow
authors.forename: Robert
authors.initials: R
authors.lastname: Booy
mesh_terms: D001315:Australia / Q000453:epidemiology; D002675:Child, Preschool; D015331:Cohort Studies; D017281:Cost of Illness; D005260:Female; D006801:Humans; D007223:Infant; D007407:Interviews as Topic; D008297:Male; D011446:Prospective Studies; D012141:Respiratory Tract Infections / Q000191:economics* / Q000453:epidemiology*; D014777:Virus Diseases / Q000191:economics* / Q000453:epidemiology*; D014780:Viruses / Q000302:isolation & purification