A two-year follow-up study of very preterm infants in Italy: aims and study design

This paper describes the objectives and study design of a population-based follow-up study of very preterm children in Italy (the ACTION 2 project), with a discussion of the methodological choices made and the difficulties encountered. Five Italian regions participated. All children born in these regions at 22-31 weeks of gestational age and discharged alive from neonatal intensive care units were eligible (n = 1407). The overall follow-up rate was 83%. Children born to foreign mothers, singletons and those with a slightly higher birth weight were less likely to return for follow-up. The assessment included a paediatric medical visit at 2 years corrected age to identify major neuromotor and sensory disability, a cognitive and behavioural screening carried out by means of a parental questionnaire, and a post-visit telephone interview with the mother. A control group of term-born 2-year-old children was recruited for the parental questionnaire and telephone interview only. The strengths of this study are the population-based approach, the large sample size and the focus on a functional assessment of development. The main limitation is the lack of formal cognitive testing. Follow-up of the cohort at school age will be necessary to obtain a full picture of the growth and development of these children.