Table 1.

Clinical characteristics of two patient groups and controls

	PIBO group (N = 37)	Bronchiolitis group (N = 30)	Controls (N = 20)	P
Age, months, mean (range)	26.2 (5–51)	22.7 (5–38)	21.5 (9–45)	0.4
Sex, male (%)	15 (41)	16 (53)	11 (55)	0.3
Atopic patients (%)	16 (44)	11 (37)	ND	0.5
Age at initial episode, months, mean (range)	16.1 (2–37)	NA
Interval between initial episode/diagnosis, months, mean (range)	8.1 (2–24)	NA
Symptom score during admission, median (range)	2 (1–4)	2 (0–4)		0.9

PIBO post-infectious bronchiolitis obliterans, ND not done, NA not available