Table 1.

Demographic features of patients with sickle cell anemia with and without asthma

	Asthma	No asthma	P
No. patients	49	242
Sex, no. (%)	.27
Male	29 (59)	121 (50)
Female	20 (41)	121 (50)
Age at entry, mean (range), y	0.27 (0.29-0.50)	0.25 (0.22-0.50)	.48
Asthma Dx age, mean (range), y*	6.2 (5.0-11.7)	6.4 (5.0-11.6)	.29
Follow-up, mean (range), y†	11.7 (0-19.0)	10.9 (0-19.6)	.23
LAO by spirometry, no. (%)‡	13 (38)	9 (7)	< .001

^*Age is the time when asthma diagnosis was first assessed.

^†Follow-up is between date of entry and the earliest of transfer away from a study clinic, last routine study visit, last special study visit, initiation of chronic blood transfusion therapy, initiation of hydroxyurea, cerebrovascular event, bone marrow transplantation, or death.

^‡Excluding 64 subjects (13 with asthma, 51 without asthma) with apparent restrictive disease.