Assessment of Neurodevelopmental Outcome in Surfactant-Replacement Therapy

Sir.—Surfactant-replacement therapy has achieved a position of great prominence recently in the pediatric literature. The article by Vaucher et al¹ in AJDC on the neurodevelopmental outcome of infants treated with human surfactant appears, like the surfactant recipients, to be premature. Two major problems are apparent. First, although the two clinical trials of surfactant replacement were carefully designed, the study population was reduced both by deaths and by those "unavailable for follow-up." Although the authors may have examined differences between those patients who returned for follow-up and those who did not, they did not present such information in their article. With the smaller sample sizes, the possibility of type II error increases and the authors' conclusions of "comparable neurologic and developmental outcome during early childhood in human surfactant-treated and control infants" are not thoroughly supported by their data. Type II error involves not rejecting the null hypothesis when it