Table 1.

Characteristics of the Sleep and Asthma Cohort (SAC) study population (N = 140) that completed both baseline polysomnography and were followed prospectively to assess acute vaso-occlusive pain events requiring hospitalization and acute chest syndrome events for a median of 5.0 years.

Characteristic	Summary statistics in cohort (n=140)#
Age at polysomnography, years	10.8 (7.2)
Male (%)	47.9
Total follow-up time after polysomnography (years)	4.9 (1.8)
Hemoglobin (g/dl)	8.1 (1.9)
White blood cell count (× 109/L)	11.7 (3.9)
Reticulocytes (%), n=139	10.2 (6.9)
Daytime hemoglobin oxygen saturation (%), n=135	97.0 (4.9)
Obstructive apnea hypopnea index	0.6 (2.0)
Nocturnal hemoglobin oxygen saturation (%)	96.4 (4.6)
Oxygen desaturation index, 3%	2.2 (5.7)
Prospective rate of pain episodes per year, mean (std. dev.)	0.57 (0.76)
Prospective rate of ACS episodes per year, mean (std. dev.)	0.17 (0.29)

^#Median and IQR are presented for variables, unless otherwise indicated.