Main characteristics of the patients at baseline
| Baseline . | HU (n = 131) . | Non-HU (n = 199) . | P . | ||
|---|---|---|---|---|---|
| Median . | SD . | Median . | SD . | ||
| Age, y | 33.0 | 11.2 | 35.0 | 12.8 | .506 |
| Follow-up, y | 8.0 | 4.7 | 5.0 | 6.0 | .009 |
| Blood units/y | 0 | 5.86 | 0 | 2.83 | .004 |
| Hospital admissions/y | 1.00 | 2.95 | 0 | 1.18 | .000 |
| Painful crises/y | 6.00 | 6.49 | 1.00 | 3.81 | < .001 |
| Hb, g/dL | |||||
| HbS/β0 | 8.90 | 1.34 | 9.20 | 1.34 | .133 |
| HbS/β+ | 9.60 | 1.25 | 9.60 | 1.77 | .407 |
| HbS/HbS | 8.70 | 1.51 | 8.90 | 2.00 | .589 |
| Leukocyte counts, ×109/L | |||||
| HbS/β0 | 11.98 | 6.73 | 9.70 | 6.16 | .045 |
| HbS/β+ | 8.40 | 5.44 | 8.70 | 4.73 | .109 |
| HbS/HbS | 11.48 | 2.90 | 12.50 | 2.86 | .445 |
| Platelet counts, ×109/L | |||||
| HbS/β0 | 332.0 | 215.0 | 280.0 | 155.9 | .096 |
| HbS/β+ | 203.0 | 142.9 | 252.5 | 169.3 | .027 |
| HbS/HbS | 463.5 | 154.5 | 382.5 | 131.9 | .079 |
| HbF, % | |||||
| HbS/β0 | 7.80 | 5.96 | 6.70 | 8.02 | .947 |
| HbS/β+ | 6.80 | 4.67 | 5.10 | 5.13 | .380 |
| HbS/HbS | 5.75 | 3.79 | 4.00 | 2.91 | .079 |
| Reticulocytes, % | |||||
| HbS/β0 | 10.0 | 7.4 | 8.0 | 7.7 | .006 |
| HbS/β+ | 9.0 | 7.41 | 6.0 | 5.45 | .017 |
| HbS/HbS | 12.0 | 6.5 | 10.0 | 4.9 | .091 |
| Bilirubin, mg/dL | |||||
| HbS/β0 | 1.65 | 3.91 | 1.80 | 2.07 | .410 |
| HbS/β+ | 1.82 | 2.26 | 1.73 | 1.25 | .317 |
| HbS/HbS | 2.81 | 2.80 | 2.70 | 1.70 | .858 |
| LDH, U/L | |||||
| HbS/β0 | 766.0 | 464.1 | 674.0 | 370.0 | .025 |
| HbS/β+ | 698.0 | 362.3 | 717.0 | 300.6 | .960 |
| HbS/HbS | 824.5 | 341.6 | 688.0 | 377.6 | .022 |
| MCV, fL | |||||
| HbS/β0 | 71.6 | 4.4 | 72.9 | 3.8 | .565 |
| HbS/β+ | 69.4 | 4.1 | 68.9 | 5.1 | .628 |
| HbS/HbS | |||||
| Baseline . | HU (n = 131) . | Non-HU (n = 199) . | P . | ||
|---|---|---|---|---|---|
| Median . | SD . | Median . | SD . | ||
| Age, y | 33.0 | 11.2 | 35.0 | 12.8 | .506 |
| Follow-up, y | 8.0 | 4.7 | 5.0 | 6.0 | .009 |
| Blood units/y | 0 | 5.86 | 0 | 2.83 | .004 |
| Hospital admissions/y | 1.00 | 2.95 | 0 | 1.18 | .000 |
| Painful crises/y | 6.00 | 6.49 | 1.00 | 3.81 | < .001 |
| Hb, g/dL | |||||
| HbS/β0 | 8.90 | 1.34 | 9.20 | 1.34 | .133 |
| HbS/β+ | 9.60 | 1.25 | 9.60 | 1.77 | .407 |
| HbS/HbS | 8.70 | 1.51 | 8.90 | 2.00 | .589 |
| Leukocyte counts, ×109/L | |||||
| HbS/β0 | 11.98 | 6.73 | 9.70 | 6.16 | .045 |
| HbS/β+ | 8.40 | 5.44 | 8.70 | 4.73 | .109 |
| HbS/HbS | 11.48 | 2.90 | 12.50 | 2.86 | .445 |
| Platelet counts, ×109/L | |||||
| HbS/β0 | 332.0 | 215.0 | 280.0 | 155.9 | .096 |
| HbS/β+ | 203.0 | 142.9 | 252.5 | 169.3 | .027 |
| HbS/HbS | 463.5 | 154.5 | 382.5 | 131.9 | .079 |
| HbF, % | |||||
| HbS/β0 | 7.80 | 5.96 | 6.70 | 8.02 | .947 |
| HbS/β+ | 6.80 | 4.67 | 5.10 | 5.13 | .380 |
| HbS/HbS | 5.75 | 3.79 | 4.00 | 2.91 | .079 |
| Reticulocytes, % | |||||
| HbS/β0 | 10.0 | 7.4 | 8.0 | 7.7 | .006 |
| HbS/β+ | 9.0 | 7.41 | 6.0 | 5.45 | .017 |
| HbS/HbS | 12.0 | 6.5 | 10.0 | 4.9 | .091 |
| Bilirubin, mg/dL | |||||
| HbS/β0 | 1.65 | 3.91 | 1.80 | 2.07 | .410 |
| HbS/β+ | 1.82 | 2.26 | 1.73 | 1.25 | .317 |
| HbS/HbS | 2.81 | 2.80 | 2.70 | 1.70 | .858 |
| LDH, U/L | |||||
| HbS/β0 | 766.0 | 464.1 | 674.0 | 370.0 | .025 |
| HbS/β+ | 698.0 | 362.3 | 717.0 | 300.6 | .960 |
| HbS/HbS | 824.5 | 341.6 | 688.0 | 377.6 | .022 |
| MCV, fL | |||||
| HbS/β0 | 71.6 | 4.4 | 72.9 | 3.8 | .565 |
| HbS/β+ | 69.4 | 4.1 | 68.9 | 5.1 | .628 |
| HbS/HbS | |||||
| . | n . | % . | n . | % . | . |
|---|---|---|---|---|---|
| Sex | |||||
| Male | 67 | 51.1 | 69 | 34.7 | .002 |
| Female | 64 | 48.9 | 130 | 65.3 | |
| Genotype | |||||
| HbS/β0 | 63 | 48.1 | 64 | 33.7 | < .001 |
| HbS/IVS1-110 | 42 | 32.1 | 64 | 32.6 | |
| HbS/IVS1-6 | 2 | 1.5 | 54 | 28.4 | |
| HbS/HbS | 24 | 18.3 | 10 | 5.3 | |
| History of chest syndrome at baseline | 8 | 6.1 | 8 | 4.0 | .388 |
| History of aseptic necrosis at baseline | 16 | 12.2 | 17 | 8.5 | .183 |
| History of stroke at baseline | 4 | 3.1 | 1 | 0.5 | .063 |
| Liver dysfunction at baseline | 33 | 25.1 | 54 | 27.1 | .312 |
| Leg ulcer at baseline | 3 | 2.2 | 5 | 2.5 | .618 |
| . | n . | % . | n . | % . | . |
|---|---|---|---|---|---|
| Sex | |||||
| Male | 67 | 51.1 | 69 | 34.7 | .002 |
| Female | 64 | 48.9 | 130 | 65.3 | |
| Genotype | |||||
| HbS/β0 | 63 | 48.1 | 64 | 33.7 | < .001 |
| HbS/IVS1-110 | 42 | 32.1 | 64 | 32.6 | |
| HbS/IVS1-6 | 2 | 1.5 | 54 | 28.4 | |
| HbS/HbS | 24 | 18.3 | 10 | 5.3 | |
| History of chest syndrome at baseline | 8 | 6.1 | 8 | 4.0 | .388 |
| History of aseptic necrosis at baseline | 16 | 12.2 | 17 | 8.5 | .183 |
| History of stroke at baseline | 4 | 3.1 | 1 | 0.5 | .063 |
| Liver dysfunction at baseline | 33 | 25.1 | 54 | 27.1 | .312 |
| Leg ulcer at baseline | 3 | 2.2 | 5 | 2.5 | .618 |
As “history of an event” at baseline, we define the presence of the event whenever before baseline.
Hb indicates hemoglobin, HU, hydroxyurea; LDH, lactate dehydrogenase; MCV, mean cell volume.