Estimates and determinants of economic impacts from influenza‐like illnesses caused by respiratory viruses in A ustralian children attending childcare: a cohort study

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 ILI s. Specimens were available for 117 ILI s: 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 ILI s 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, ILI s 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.