Observational Research in Childhood Infectious Diseases (ORChID): a dynamic birth cohort study

Lambert, Stephen Bernard; Ware, Robert S; Cook, Anne L; Maguire, Frances A; Whiley, David M; Bialasiewicz, Seweryn; Mackay, Ian M; Wang, David; Sloots, Theo P; Nissen, Michael D; Grimwood, Keith

Like most observational studies, recruitment is non-random, requiring assessment of potential biases and confounders prior to considering the internal and external validity of any findings. Where reported, oversampling of families from higher socioeconomic households appears common in research similar to this study, 14 63 88 although differences in incidence and cost of illnesses mean that any impact on burden assessment is likely to be minimal and biased toward the null. We have attempted to avoid this selection bias by using a large, public hospital as one of our two recruitment sites. The role household socioeconomic status plays on incidence and disease burden will be assessed in the study analysis. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 with blinded real-time PCR commenced for respiratory viruses. The study will provide unique insights on the acquisition of viruses, duration of shedding, and the relationship of these to symptomatic illness. As well as this, specimens will be available for targeted discovery of new pathogens, and will provide a rich source of material to define the epidemiology of new agents when described by others.