eDiary-recorded endpoints. The rate ratio (active vs placebo) of pain crises (A), analgesic use at home (B), and opioid analgesic use at home (C) were calculated using a Poisson regression model with a log-link and with treatment, baseline disease severity, age group, and HU use as covariates. The model used the log of (days in the study/365) as the offset variable to produce the annualized rates. P values were testing to see whether the rate ratio is different from placebo. The odds of absence from school because of SCD pain (D) were calculated as the number of days missed (eDiary Q7 response of “Yes”) divided by the number of days available to be missed (eDiary Q7 response of “Yes,” “No, went to school,” or “No, other”). Least squares proportion estimates, CIs, and comparison P values are from a logistic regression with treatment, baseline disease severity, age group, and HU use as covariates. P values are testing to see whether the odds ratio is different from 1.