Article Text
Abstract
Background Preterm children are at increased risk of morbidity throughout childhood. However, few studies have investigated the long-term health consequences in relation to the full spectrum of gestational age, week-by-week. This study aimed to estimate the effect of gestational age on hospital admissions from birth up to 10 years of age, explore how rates of hospitalisation change throughout childhood.
Methods Birth registration and hospital admission records were linked for all live, singleton births occurring in England between in 2005 and 2006. Children (n=1,018,136) were followed up from birth admission hospital discharge to age 10, death or study end (31st March 2015). Generalised estimating equations were used to estimate rate ratios (RR) with 95% confidence intervals (CI). The analysis was repeated looking at infection-related hospital admissions only.
Results Compared to children born at 40 weeks, those born <28 weeks had the highest rates of hospital admission throughout childhood (aRR=4.89, 95%CI=4.55–5.26). Even children born at 38 weeks had a higher rate of hospital admission during childhood compared to those born at 40 weeks (aRR=1.19, 95%CI=1.16–1.22). However, the effect of gestational age on hospital admission decreased as the children became older (interaction p<0.0001). The most common cause of hospital admissions throughout childhood was infection and similar results were observed when the analysis was restricted to infection-related hospital admissions only e.g. <28 vs. 40 weeks, aRR=5.57, 95%CI=5.01–5.91. Gestational age had the strongest effect on rates of lower respiratory tract infections, invasive bacterial and viral infection-related admissions.
Conclusion Gestational age is a strong predictor of childhood morbidity, particularly infection-based morbidity, with those born the most preterm at the highest risk. Whilst the effect of gestational age on hospital admission rates decreases with age, an excess risk remained at age 7–10 years.