To the Editor.
—I read with interest the work by Dr Als and colleagues.1 Although they address a few limitations of their trial, I do not feel that all limitations were adequately covered.My first concern is that we are never told when this randomized trial was conducted. If this randomized trial was conducted prior to the widespread use of surfactant at Joint Program in Neonatology (JPN) nurseries, as suggested in the Editorial,2 then I assume it occurred anywhere from 1984 to October 1989 when surfactant became available in JPN nurseries.3 Since the time of the study, management of infants with severe respiratory distress syndrome has changed considerably at JPN and other nurseries. Randomized trials conducted prior to these changes may not provide information that is generalizable to 1994 nurseries.A second concern is with assessment of illness severity at enrollment. Although groups were statistically similar for