Percent predicted of forced vital capacity (FEV₁% predicted) declined minimally over time in children with sickle cell anemia in a prospective longitudinal multi-center cohort study involving 197 children. Additionally, sickle cell disease characteristics and therapy did not predict this decline. Participants included children with sickle cell anemia from the Sleep and Asthma Cohort study. Investigators looked at spirometry measures taken from baseline to the end of the study. Among the results:

• FEV₁% predicted declined by 0.3% for every additional year of age.
• Gender, asthma history, hemoglobin, reticulocyte count, white blood cell count, severe acute pain and acute chest syndrome episode rates, and hydroxyurea therapy were not linked with a decline in FEV₁% predicted.