Characteristic Overall
N = 4051
With AVN
N = 881
Without AVN
N = 3171
p-value2
Age (yr) 35 (25, 47) 40 (32, 48) 34 (24, 47) 0.007
Female 189 (47%) 42 (48%) 147 (46%) 0.8
Sickle Cell Type


0.7
    SS 297 (73%) 66 (75%) 231 (73%)
    SC 72 (18%) 13 (15%) 59 (19%)
    SB+ (thalassemia) 16 (4.0%) 5 (5.7%) 11 (3.5%)
    Other 20 (4.9%) 4 (4.5%) 16 (5.0%)
Alpha-thalassemia


0.15
    Wild Type 274 (68%) 57 (65%) 217 (68%)
    One Deletion 123 (30%) 27 (31%) 96 (30%)
    Two Deletions 8 (2.0%) 4 (4.5%) 4 (1.3%)
Current Hydroxyurea Use 165 (41%) 45 (51%) 120 (38%) 0.025
Hemoglobin F (%) 5 (2, 10) 7 (2, 13) 4 (2, 9) 0.038
Hematocrit (%) 26.9 (22.7, 31.5) 27.9 (24.0, 31.0) 26.4 (22.2, 31.5) 0.3
Hemoglobin (g/dL) 9.2 (8.0, 10.8) 9.4 (8.4, 10.9) 9.1 (7.8, 10.8) 0.4
White Blood Cells (cells/µL) 9.5 (7.4, 12.1) 9.5 (7.0, 12.2) 9.5 (7.5, 11.9) 0.8
History of Smoking 126 (31%) 35 (40%) 91 (29%) 0.047
Presence of Chronic Pain 146 (36%) 47 (53%) 99 (31%) <0.001
Number of VOC Episodes/Year 1 (0, 2) 1 (0, 3) 1 (0, 2) 0.007
BMI 23.7 (21.3, 27.4) 24.4 (22.7, 27.7) 23.5 (20.9, 27.1) 0.067
1 Median (IQR); n (%)
2 Wilcoxon rank sum test; Pearson’s Chi-squared test; Fisher’s exact test