Participant characteristics for the total sample and by age
| Characteristic . | Total sample (N = 421) . | School age (n = 192) . | Early adolescence (n = 69) . | Late adolescence (n = 160) . | P value . |
|---|---|---|---|---|---|
| N (%) . | N (%) . | N (%) . | N (%) . | ||
| Sex | .56 | ||||
| Male | 212 (50.36) | 98 (51.04) | 38 (55.07) | 76 (47.50) | |
| Female | 209 (49.64) | 94 (48.96) | 31 (44.93) | 84 (52.50) | |
| Genotype | .81 | ||||
| SS | 241 (57) | 113 (59) | 38 (55) | 90 (56) | |
| Sβ0 | 19 (5) | 8 (4) | 1 (1) | 10 (6) | |
| SC | 120 (28) | 54 (28) | 24 (35) | 42 (26) | |
| Sβ+ | 37 (9) | 15 (8) | 5 (7) | 17 (11) | |
| Other∗ | 4 (1) | 2 (1) | 1 (2) | 1 (1) | |
| HU before time of evaluation | 224 (53.21) | 104 (54.17) | 30 (43.48) | 90 (56.25) | .19 |
| Chronic transfusion before time of evaluation | 56 (13.3) | 19 (9.90) | 12 (17.39) | 25 (15.62) | .16 |
| Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | P value | |
| Age at HU initiation, y | 6.44 (3.89) | 4.5 (2.48) | 6.9 (3.11) | 8.53 (4.34) | <.001 |
| Age at chronic transfusions, y | 5.75 (4.49) | 3.17 (1.93) | 4.99 (2.66) | 8.08 (5.38) | .0052 |
| Hemoglobin, g/dL | 10.02 (1.66) | 9.87 (1.61) | 9.81 (1.65) | 10.3 (1.70) | .14 |
| WBC count, × 109/L | 9.04 (3.89) | 9.22 (3.99) | 9.16 (3.52) | 8.77 (3.91) | .39 |
| Platelet count, × 109/L | 343.66 (166.48) | 345.83 (151) | 330.66 (149.96) | 346.78 (190.74) | .69 |
| Fetal hemoglobin, % | 13.21 (10.4) | 14.37 (10.60) | 10.74 (10.25) | 12.65 (10.02) | .048 |
| Social vulnerability index† | 0.64 (0.26) | 0.64 (0.26) | 0.61 (0.29) | 0.66 (0.25) | .56 |
| Age at evaluation, y | 12.01 (3.36) | 8.81 (0.52) | 12.28 (0.84) | 15.72 (1.71) | <.001 |
| Characteristic . | Total sample (N = 421) . | School age (n = 192) . | Early adolescence (n = 69) . | Late adolescence (n = 160) . | P value . |
|---|---|---|---|---|---|
| N (%) . | N (%) . | N (%) . | N (%) . | ||
| Sex | .56 | ||||
| Male | 212 (50.36) | 98 (51.04) | 38 (55.07) | 76 (47.50) | |
| Female | 209 (49.64) | 94 (48.96) | 31 (44.93) | 84 (52.50) | |
| Genotype | .81 | ||||
| SS | 241 (57) | 113 (59) | 38 (55) | 90 (56) | |
| Sβ0 | 19 (5) | 8 (4) | 1 (1) | 10 (6) | |
| SC | 120 (28) | 54 (28) | 24 (35) | 42 (26) | |
| Sβ+ | 37 (9) | 15 (8) | 5 (7) | 17 (11) | |
| Other∗ | 4 (1) | 2 (1) | 1 (2) | 1 (1) | |
| HU before time of evaluation | 224 (53.21) | 104 (54.17) | 30 (43.48) | 90 (56.25) | .19 |
| Chronic transfusion before time of evaluation | 56 (13.3) | 19 (9.90) | 12 (17.39) | 25 (15.62) | .16 |
| Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | P value | |
| Age at HU initiation, y | 6.44 (3.89) | 4.5 (2.48) | 6.9 (3.11) | 8.53 (4.34) | <.001 |
| Age at chronic transfusions, y | 5.75 (4.49) | 3.17 (1.93) | 4.99 (2.66) | 8.08 (5.38) | .0052 |
| Hemoglobin, g/dL | 10.02 (1.66) | 9.87 (1.61) | 9.81 (1.65) | 10.3 (1.70) | .14 |
| WBC count, × 109/L | 9.04 (3.89) | 9.22 (3.99) | 9.16 (3.52) | 8.77 (3.91) | .39 |
| Platelet count, × 109/L | 343.66 (166.48) | 345.83 (151) | 330.66 (149.96) | 346.78 (190.74) | .69 |
| Fetal hemoglobin, % | 13.21 (10.4) | 14.37 (10.60) | 10.74 (10.25) | 12.65 (10.02) | .048 |
| Social vulnerability index† | 0.64 (0.26) | 0.64 (0.26) | 0.61 (0.29) | 0.66 (0.25) | .56 |
| Age at evaluation, y | 12.01 (3.36) | 8.81 (0.52) | 12.28 (0.84) | 15.72 (1.71) | <.001 |
P values are based on χ2 test for categorical variables and Kruskal-Wallis rank sum test for continuous variables, respectively.
HU, hydroxyurea; WBC, white blood cell.
Other genotypes include S/HPFH, S/O-Arab, S/gamma delta beta (γδβ), and S/another variant hemoglobin. SS and Sβ0 were combined when conducting a test or in a model-based analysis.
Classifies individuals on the basis of social vulnerabilities at the neighborhood level (eg, housing data, poverty, and education); higher values indicate higher social vulnerability.