The Tennessee Children's Respiratory Initiative: Objectives, design and recruitment results of a prospective cohort study investigating infant viral respiratory illness and the development of asthma and allergic diseases

Abstract

Background and objective: The 'attack rate' of asthma following viral lower respiratory tract infections (LRTI) is about 3-4 fold higher than that of the general population; however, the majority of children who develop viral LRTI during infancy do not develop asthma, and asthma incidence has been observed to continuously decrease with age. Thus, we do not understand how viral LRTI either predispose or serve as a marker of children to develop asthma. The Tennessee Children's Respiratory Initiative has been established as a longitudinal prospective investigation of infants and their biological mothers. The primary goals are to investigate both the acute and the long-term health consequences of varying severity and aetiology of clinically significant viral respiratory tract infections on early childhood outcomes.

Methods: Over four respiratory viral seasons, 2004–2008, term, predominantly non-low weight previously healthy infants and their biological mothers were enrolled during an infant's acute viral respiratory illness.Longitudinal follow up to age 6 years is ongoing [corrected].

Results: This report describes the study objectives, design and recruitment results of the over 650 families enrolled in this longitudinal investigation. The Tennessee Children's Respiratory Initiative is additionally unique because it is designed in parallel with a large retrospective birth cohort of over 95,000 mother-infant dyads with similar objectives to investigate the role of respiratory viral infection severity and aetiology in the development of asthma.

Conclusions: Future reports from this cohort will help to clarify the complex relationship between infant respiratory viral infection severity, aetiology, atopic predisposition and the subsequent development of early childhood asthma and atopic diseases.

Figure 1

Flow diagram of participants through the screening, enrolment and initial analysis phases of the Tennessee Children's Respiratory Initiative. LRTI, lower respiratory tract infections; URI, upper respiratory tract infection.

Figure 2

Weekly enrolment during the September through May enrolment periods of the Tennessee Children's Respiratory Initiative, 2004–2008. () all patients. () inpatients. () outpatients.