Bias in reported neurodevelopmental outcomes among extremely low birth weight survivors

Objectives. The purpose of this study was to investigate possible bias in the evaluation of neurodevelopment and somatic growth at 18 to 22 months' postmenstrual age among extremely low birth weight (ELBW) survivors (401-1000 g at birth). Methods. Data from a cohort of 1483 ELBW infant survivors who were born January 1993 through December 1994 and cared for at centers in the Neonatal Research Network of the National Institute of Child Health and Human Development were examined retrospectively. Children who were compliant with an 18- to 22-month follow-up visit, who visited but were not measured, or who made no visit were compared regarding 4 outcomes: 1) Bayley Scales of Infant Development, 2nd edition, Mental Developmental Index (MDI) Results. Compared with children who were lost to follow-up, those who were compliant with follow-up were more likely to have been 1 of a multiple birth, to have received postnatal glucocorticoids, and to have had chronic lung disease. These factors were significantly associated with MDI and PDI Conclusion. ELBW infant survivors who weighed 401 to 1000 g at birth and who are compliant with follow-up evaluations may have worse Bayley Scales of Infant Development, 2nd edition, MDI scores than infants with no visit. Thus, follow-up studies based on infants who are compliant with follow-up care may lead to an overestimation of adverse outcomes in ELBW survivors. Pediatrics 2004;114:404-410; neurodevelopmental, outcomes, cerebral palsy, follow-up, extremely low birth weight infants.
ABBREVIATIONS. ELBW, extremely low birth weight; NICHD, National Institute of Child Health and Human Development; NICU, neonatal intensive care unit; CP, cerebral palsy; BSID-II, Bayley Scales of Infant Development, 2nd [...]