First Year of Life Medication Use and Hospital Admission Rates: Premature Compared with Term Infants

Abstract

To compare hospitalization and medication use during the first year of life in preterm-born and term-born infants. Data for this retrospective cohort study were obtained from the linked PHARMO-Netherlands Perinatal Registry cohort. From this linked birth cohort, preterm infants (<37 weeks) born between 2004 and 2007 were randomly matched to 4 full-term infants. During follow-up, hospitalization and medication use were assessed. Cox proportional hazard regression models were used to estimate and compare the relative risk (RR) of hospitalization and medication use in preterm and full-term infants. Population-attributable risk percentages were calculated to estimate the proportion of hospitalizations and medication use attributable to preterm birth. Among the 71,607 singletons born between 2004-2007, 4277 (6%) were born preterm. Of these, 90% were hospitalized at birth, compared with 55% of full-term infants. Preterm infants were twice as likely to be rehospitalized (RR, 2.0; 95% CI, 1.9-2.2), specifically for respiratory-related diseases. Prematurity accounted for 6% of the respiratory disease readmissions. The most frequently used outpatient drugs in the second half year of life were antibacterials for systemic use and drugs for obstructive airway diseases. Preterm infants were 50% more likely to receive a respiratory medication (RR, 1.5; 95% CI, 1.4-1.7). In the first year of life, preterm born infants are up to 2 times more likely than full-term infants to be hospitalized or use medication, especially related to respiratory disease.