Demographics and descriptive statistics for the patient and control subjects included in this study
| . | Control Subjects . | Patients . | P value . |
|---|---|---|---|
| Participants, N | 54 | 92 | |
| Age (y), mean ± SD (range) | 15.9 ± 5.2 (6.7 to 30.6) | 16.8 ± 6.0 (8.0 to 38.8) | .318 |
| Sex ratio | 32F:22M | 43F:49M | .197 |
| Genotype | 15 HbAA, 14 HbAS, 2 HbAC, 23 unknown | 91 HbSS, 1 HbSβ0 thalassemia | — |
| Seizures, n (%) | — | 3 (3) | — |
| Headaches, n (%) | — | 33 (36) | — |
| Systolic blood pressure >90th centile, n (%) | — | 26 (28) | — |
| Diastolic blood pressure >90th centile, n (%) | — | 3 (3) | — |
| Peripheral oxygen saturation (%), mean ± SD (range) | 98.4 ± 1.2 (96 to 100)∗ | 96.8 ± 2.6 (89 to 100) | .001 |
| Hb level (g/L), mean ± SD (range) | N/A | 87.2 ± 14.6 (51 to 134) | — |
| Hydroxyurea treatment, n (%) | — | 34 (37) | — |
| Chronic transfusion treatment, n (%) | — | 5 (5) | — |
| Penicillin and folic acid only, n (%) | — | 53 (58) | — |
| SCI, n (%) | 8 (15) | 38 (41) | <.0005 |
| SCI on hydroxyurea, n (%) | — | 14/34 (41) | — |
| SCI on no treatment, n (%) | — | 24/58 (41) | — |
| Number of SCIs, median (range) | 0 (0 to 8) | 0 (0 to 26) | .03 |
| Volume of SCIs, median (range) | 0 (0 to 1075) | 0 (0 to 5071) | .03 |
| Full-scale intelligence quotient, mean ± SD (range) | 101.4 ± 18.1 (75 to 112) | 92.6 ± 13.3 (58 to 122) | .011 |
| Processing speed index, mean ± SD (range) | 95.7 ± 4.2 (53 to 115) | 89.0 ± 13.2 (59 to 118) | .022 |
| Working memory index, mean ± SD (range) | 96.9 ± 9.7 (65 to 114) | 91.0 ± 13.0 (56 to 122) | .012 |
| Time between cognitive assessment and Hb (d), median (range) | — | −6.5 (−180 to 270) | — |
| . | Control Subjects . | Patients . | P value . |
|---|---|---|---|
| Participants, N | 54 | 92 | |
| Age (y), mean ± SD (range) | 15.9 ± 5.2 (6.7 to 30.6) | 16.8 ± 6.0 (8.0 to 38.8) | .318 |
| Sex ratio | 32F:22M | 43F:49M | .197 |
| Genotype | 15 HbAA, 14 HbAS, 2 HbAC, 23 unknown | 91 HbSS, 1 HbSβ0 thalassemia | — |
| Seizures, n (%) | — | 3 (3) | — |
| Headaches, n (%) | — | 33 (36) | — |
| Systolic blood pressure >90th centile, n (%) | — | 26 (28) | — |
| Diastolic blood pressure >90th centile, n (%) | — | 3 (3) | — |
| Peripheral oxygen saturation (%), mean ± SD (range) | 98.4 ± 1.2 (96 to 100)∗ | 96.8 ± 2.6 (89 to 100) | .001 |
| Hb level (g/L), mean ± SD (range) | N/A | 87.2 ± 14.6 (51 to 134) | — |
| Hydroxyurea treatment, n (%) | — | 34 (37) | — |
| Chronic transfusion treatment, n (%) | — | 5 (5) | — |
| Penicillin and folic acid only, n (%) | — | 53 (58) | — |
| SCI, n (%) | 8 (15) | 38 (41) | <.0005 |
| SCI on hydroxyurea, n (%) | — | 14/34 (41) | — |
| SCI on no treatment, n (%) | — | 24/58 (41) | — |
| Number of SCIs, median (range) | 0 (0 to 8) | 0 (0 to 26) | .03 |
| Volume of SCIs, median (range) | 0 (0 to 1075) | 0 (0 to 5071) | .03 |
| Full-scale intelligence quotient, mean ± SD (range) | 101.4 ± 18.1 (75 to 112) | 92.6 ± 13.3 (58 to 122) | .011 |
| Processing speed index, mean ± SD (range) | 95.7 ± 4.2 (53 to 115) | 89.0 ± 13.2 (59 to 118) | .022 |
| Working memory index, mean ± SD (range) | 96.9 ± 9.7 (65 to 114) | 91.0 ± 13.0 (56 to 122) | .012 |
| Time between cognitive assessment and Hb (d), median (range) | — | −6.5 (−180 to 270) | — |
HbAA, normal hemoglobin; HbAC, heterozygous for hemoglobins A & C; HbAS, heterozygous for hemoglobins A & S; HbSβ0, heterozygous sickle β0; HbSS,homozygous for hemoglobin S; SCI, silent cerebral infarct.
Difference statistics and P values from χ2 tests of equal proportions and two-sample t tests are given as appropriate, with significant P values (for α = 0.05) shown in bold.
Control subjects with peripheral oxygen saturation (n = 38).