Abstract
Background: The longitudinal birth cohort study is the preferred design for studies of childhood health, particularly asthma and other atopic diseases. Still, prospective data collection depends on recollection of the medical history representing a potential recall-bias.
Aims: We aimed to ascertain completeness of our data on atopic disease and other health symptoms reported in a closely monitored birth cohort study. Possible bias from symptom severity and socioeconomics were sought.
Methods: The Copenhagen study on Asthma in Childhood (COPSAC) is a clinical birth cohort study of 411 children. Child health is monitored at 6-montly clinic visits from birth till age 3 with a particular emphasis on asthma and other atopic diseases. Cohort information of 260 children was compared with the records from family practitioner as an external reference.
Results: A total of 6134 medical events were reported at the COPSAC interviews. Additional 586 medical events were recorded by family practitioners, but not reported at the interview. None of these missed events were related to atopic disease. Respiratory, infectious and skin related symptoms showed completeness above 90%, other diseases showed lower completeness around 77%. There was no meaningful influence from concurrent asthma or socioeconomics, including household income, mother's education or employment.
Conclusion: The COPSAC study exhibited full completeness to the main study objectives, atopic disease, and high completeness to respiratory, infectious and skin related illness. Our findings support the validity of clinical interviews of parents in longitudinal cohort studies investigating childhood illness and atopic disease in childhood.
- © 2011 ERS
