Table 1. Patient Characteristics Based on Daily Opioid Use.

Median (interquartile range) or percent is shown. Patient characteristics were compared using Spearman correlation analysis for continuous variables or Cochran trend test for categorical variables.

Daily opioid dose quartile	N	1	N	2	N	3	N	4	p-value
Daily opioid dose (mg OME)	51	0 (0-0)	51	1.1 (0.7-1.7)	51	6.3 (3.7-8.8)	50	57.3 (28.8-111.8)	<0.001
Gender (%male)	51	45	51	22	51	41	50	40	0.9
Age (yo)	51	30 (21-46)	51	31 (23-42)	51	39 (28-45)	50	36 (28-45)	0.03
SCD genotype (%SS/Sbeta0)	51	77	51	75	51	71	50	80	0.81
On hydroxyurea (%)	51	24	51	28	51	51	50	50	0.001
History of AVN (%)	50	6	50	22	51	22	50	40	<0.001
25-OHD (ng/mL)	46	19 (11-27)	49	16 (9-23)	51	15 (9-23)	47	14 (8-26)	0.06
WBC ( × 109/L)	49	8.4 (7.0-10.5)	51	8.8 (7.2-11.4)	51	9.0 (6.9-11.6)	50	9.2 (7.1-12.6)	0.24
Hemoglobin (g/dL)	49	9.0 (7.9-10.5)	51	9.0 (8.0-10.1)	51	8.7 (7.9-10.3)	50	9.1 (7.6-10.7)	0.79
Hemoglobin F (%)	34	3.8 (1.5-8.5)	35	4.4 (2.1-7.9)	44	5.4 (2.3-11.6)	39	5.9 (3.3-11.2)	0.02
Absolute reticulocyte (×109/L)	44	283 (218-420)	45	318 (198-432)	47	322(188-426)	42	273 (181-354)	0.26
Reticulocyte (%)	44	11.5 (6.1-14.9)	45	11.6 (5.8-14.7)	47	11.7 (6.2-18.0)	42	9.3 (6.5-14.0)	0.49
MCV (fl)	49	90 (84-102)	51	90 (82-101)	51	94 (87-109)	50	92 (81-102)	0.36
Total bilirubin (mg/dL)	42	2.7 (1.8-6.1)	40	2.3 (1.6-4.1)	35	2.0 (1.4-2.5)	36	1.8 (1.2-3.3)	0.007
Direct bilirubin (mg/dL)	9	0.6 (0.3-0.9)	16	0.4 (0.3-0.5)	12	0.5 (0.4-0.6)	7	0.4 (0.3-0.5)	0.36
Indirect bilirubin (mg/dL)	9	3.0 (1.7-7.3)	16	1.9 (1.2-3.3)	12	1.8 (1.1-3.7)	7	1.2 (0.9-1.3)	0.008
LDH (u/L)	13	428 (354-509)	18	282 (255-321)	11	373 (249-427)	14	330 (220-392)	0.14
AST (u/L)	42	37 (27-64)	40	37 (29-52)	35	30 (23-44)	36	35 (27-51)	0.17
ALT (u/L)	42	23 (15-29)	40	24 (16-24)	35	18 (16-28)	36	23 (14-35)	0.64