Table 3

Results of single variable* logistic regression for adverse events (n=1319 patients)

Characteristic	N	n (%)	OR	P value
Sex				0.38
Male	668	19 (2.8)	Ref
Female	651	14 (2.2)	0.73 (0.36–1.46)
Both parents (or single parent) speak English or French				0.44
Yes	1260	31 (2.5)	Ref
No	59	2 (3.4)	1.74 (0.35–5.42)
Both parents (or single parent) are immigrants†				0.22
No	1244	33 (2.7)	Ref
Yes	71	0 (0.0)	0.26 (0.00–1.84)
Paediatric Canadian Triage Acuity Scale				0.23
1, 2 Resus/emergent	84	1 (1.2)	Ref
3 Urgent	664	22 (3.3)	1.96 (0.50–17.75)
4, 5 Semiurgent/non-urgent	571	10 (1.8)	1.07 (0.25–10.04)
After hours				0.47
No (08:00 to 17:00)	735	16 (2.2)	Ref
Yes (>17:00 to <08:00)	584	17 (2.9)	0.64 (0.22–2.48)
Weekend				0.02
No (Mon–Friday)	915	29 (3.2)	Ref
Yes (Saturday–Sunday)	404	4 (1.0)	0.35 (0.11–0.87)
Disposition				0.98
Discharged	1235	32 (2.6)	Ref
Admitted	66	1 (1.5)	0.87 (0.10–3.39)
Left without being seen or against medical advice	18	0 (0.0)	1.00 (0.01–7.65)
Indwelling line or urinary catheter, or dialysis catheter or respiratory support needed			0.74 (0.06–5.52)	0.83
No	1294	33 (2.6)	Ref
Yes	25	0 (0.0)	0.74 (0.06–5.52)
Mental health visit				0.04
No	1301	31 (2.4)	Ref
Yes	18	2 (11.1)	5.68 (1.09–19.41)
Patient has at least one chronic medical condition				0.89
No	1043	26 (2.5)	Ref
Yes	276	7 (2.5)	1.06 (0.43–2.29)
Arrival by ambulance
No	1263	29 (2.3)	Ref
Yes	56	4 (7.1)	3.39 (1.05–8.74)
Initial ED location				0.94
Main ED	324	10 (3.1)	Ref
Ambulatory zone/minor treatment area	995	23 (2.3)	0.62 (0.08–79.79)
Subspecialty services involved‡
No	1250	30 (2.4)	Ref	0.12
Yes	54	3 (5.6)	2.78 (0.73–7.73)
Primary assessor was ED staff§				0.38
No	769	22 (2.9)	Ref
Yes	524	11 (2.1)	0.73 (0.34–1.47)
Number of ED staff physicians involved in patient’s care§				0.59
1	1212	31 (2.6)	Ref
2	69	2 (2.9)	1.42 (0.28–4.40)
3+	3	0 (0.0)	5.43 (0.04–60.75)
Continuous variables
Patient level
Age in years, median (IQR)		11.87 (1.29–15.48)		<0.001
Linear term			0.96 (0.87–1.05)
Quadratic term			1.02 (1.01–1.04)
Time to see doctor (hours), median (IQR)		1.13 (0.78–1.95)	0.97 (0.64–1.24)	0.87
Number of patients waiting to be seen when registered, median (IQR)		14 (11-20)		0.55
Linear term			1.04 (0.98–1.10)
Quadratic term			1.00 (0.99–1.00)
ED census at time of registration, median (IQR)		31 (27–42)	1.02 (0.99–1.06)	0.18
Number of patients awaiting admission to the ward, median (IQR)		2 (1–3)	1.01 (0.81–1.23)	0.49
LOS in the ED (hours) (time to discharge OR time to admission to floor), median (IQR)		3.08 (1.87–4.28)	1.10 (0.99–1.20)	0.08

*All logistic regression analyses adjusted for shift (day, evening, night) to account for oversampling of night shifts.
†N is less than 1319 as this data were not collected for four enrolled patients.
‡N is less than 1319 as this does not include the 15 patients who left without being seen. Patients who were seen directly by subspecialty service (n=11) and those patients who were seen first by ED-specific services but for whom a referral to a subspecialty service was also made (n=43) were deemed as having subspecialty service involvement.
§N is less than 1319 as includes only the 1293 patients seen by ED-specific services (11 were seen by subspecialty services directly and 15 left without being seen).
¶N is less than 1319 as this includes only patients seen by an ED-specific service physician (9 of the 1293 patients seen by ED-specific services were managed by a mental health crisis worker with no ED physician involvement).
ED, emergency department; LOS, length of stay.