Enrollment characteristics of the SACRED cohort, according to assignment to the observation cohort or treatment cohort, with treatment listed at the time of the initial screening TCD examination
| Treatment at exam . | Observation cohort N = 209 . | Hydroxyurea treatment cohort N = 50 . | P value . | |||
|---|---|---|---|---|---|---|
| None . | Hydroxyurea . | Transfusions . | None . | Hydroxyurea . | ||
| No. of participants | 115 | 51 | 43 | 38 | 12 | |
| Age, y | 8.9 ± 3.4 | 9.6 ± 3.4 | 9.0 ± 3.0 | 6.6 ± 2.7 | 7.4 ± 3.1 | .0002 |
| Sex, female, n (%) | 58 (50.4) | 21 (41.2) | 18 (41.9) | 18 (47.4) | 5 (41.7) | .7493 |
| Palpable spleen, n (%) | 12 (10.4) | 4 (7.8) | 3 (7.0) | 5 (13.2) | 0 (0.0) | .6349 |
| Oxygen saturation, % | 97.3 ± 1.3 | 97.4 ± 1.5 | 97.4 ± 1.4 | 97.3 ± 1.3 | 97.3 ± 1.3 | 1.0000 |
| Hb, g/dL | 8.0 ± 1.2 | 8.3 ± 1.1 | 8.7 ± 1.1 | 7.4 ± 0.8 | 8.1 ± 1.0 | .0046 |
| ANC, × 109/L | 7.4 ± 3.0 | 7.2 ± 2.6 | 8.2 ± 2.8 | 8.2 ± 3.0 | 7.3 ± 5.0 | .1562 |
| HbF, % | 15.6 ± 8.8 | 17.4 ± 9.4 | 10.8 ± 10.7 | 16.3 ± 8.0 | 14.2 ± 6.9 | .6646 |
| α-Thalassemia, n (%) | 34 (29.6) | 12 (23.5) | 10 (23.3) | 8 (21.1) | 2 (16.7) | .3105 |
| G6PD deficiency, n (%) | 5 (8.8) | 1 (3.3) | 1 (4.0) | 3 (15.0) | 1 (14.3) | .3875 |
| Treatment at exam . | Observation cohort N = 209 . | Hydroxyurea treatment cohort N = 50 . | P value . | |||
|---|---|---|---|---|---|---|
| None . | Hydroxyurea . | Transfusions . | None . | Hydroxyurea . | ||
| No. of participants | 115 | 51 | 43 | 38 | 12 | |
| Age, y | 8.9 ± 3.4 | 9.6 ± 3.4 | 9.0 ± 3.0 | 6.6 ± 2.7 | 7.4 ± 3.1 | .0002 |
| Sex, female, n (%) | 58 (50.4) | 21 (41.2) | 18 (41.9) | 18 (47.4) | 5 (41.7) | .7493 |
| Palpable spleen, n (%) | 12 (10.4) | 4 (7.8) | 3 (7.0) | 5 (13.2) | 0 (0.0) | .6349 |
| Oxygen saturation, % | 97.3 ± 1.3 | 97.4 ± 1.5 | 97.4 ± 1.4 | 97.3 ± 1.3 | 97.3 ± 1.3 | 1.0000 |
| Hb, g/dL | 8.0 ± 1.2 | 8.3 ± 1.1 | 8.7 ± 1.1 | 7.4 ± 0.8 | 8.1 ± 1.0 | .0046 |
| ANC, × 109/L | 7.4 ± 3.0 | 7.2 ± 2.6 | 8.2 ± 2.8 | 8.2 ± 3.0 | 7.3 ± 5.0 | .1562 |
| HbF, % | 15.6 ± 8.8 | 17.4 ± 9.4 | 10.8 ± 10.7 | 16.3 ± 8.0 | 14.2 ± 6.9 | .6646 |
| α-Thalassemia, n (%) | 34 (29.6) | 12 (23.5) | 10 (23.3) | 8 (21.1) | 2 (16.7) | .3105 |
| G6PD deficiency, n (%) | 5 (8.8) | 1 (3.3) | 1 (4.0) | 3 (15.0) | 1 (14.3) | .3875 |
At initial screening, a total of 50 children had conditional TCD velocities and received hydroxyurea treatment per protocol, including 38 treatment-naïve children and 12 whose current hydroxyurea dose was optimized.
HbF is calculated as HbF/(HbF + HbS).
G6PD deficiency refers only to males.
P value compares children in each cohort receiving no disease-modifying treatment (n = 115 vs n = 38).
ANC, absolute neutrophil count; HbF, fetal hemoglobin; HbS, sickle hemoglobin.