Table 2

Variables associated with admission in the evening or at night compared with day

		Univariate analysis				Logistic regression
		Odds ratio	95% CI			Odds ratio	95% CI
Time ill before presentation
⩽ 6 hours	Baseline			Baseline
> 6 hours and ⩽ 24 hours	0.88	0.55 to 1.44		0.75	0.42 to 1.36
> 24 hours	0.62^*	0.42 to 0.90		0.56^*	0.36 to 0.88
Breathing difficulty as presenting problem	1.45^*	1.02 to 2.05		1.64^*	1.05 to 2.57
Diagnosis of croup	2.25^*	1.02 to 4.97		NS	–
Diagnosis of viral infection	2.32^*	1.1 to 4.91		NS	–
Associated problem	0.55^*	0.34 to 0.88		0.50^*	0.26 to 0.93

Logistic regression is adjusted for variables measurable at time of admission with p < 0.1 in univariate analysis (age, Carstairs score, duration of illness, presenting problem, and hospital).
2-150 p ⩽ 0.05.