Fig. 1

Separation of hemoglobin levels between the treatment groups. Hemoglobin levels in the higher-threshold and lower-threshold groups were recorded before enrollment and until 36 weeks of postmenstrual age. Values are means and 95% confidence intervals (indicated by I bars), adjusted for infant as a random effect. Hemoglobin tests were performed at clinical discretion and were not dictated by protocol. A shows the hemoglobin levels that prompted a red-cell transfusion. B shows all hemoglobin levels that were measured in the two groups during the treatment period. (Used with permission from NEJM)