Table 4

Association between ambulance diversion of the nearest ED and access, treatment and outcomes, based on alternative models

Base rate (among patients in reference group)	Treatment			Outcomes
	Catheterisation/PCI	Thrombolytic therapy	CABG	30-day mortality	90-day mortality	1-year mortality	30-day readmission
	(51%)	(1%)	(6%)	(16%)	(22%)	(29%)	(34%)
Diversion status (reference group: nearest ED not on diversion on the day of admission)
Nearest ED’s exposure to diversion on the day of admission
<6 h	−0.51	0.16	−0.37	−0.25	0.09	−0.24	0.00
	(−1.85, 0.84)	(−0.24, 0.57)	(−1.13, 0.38)	(−1.31, 0.82)	(−1.16, 1.35)	(−1.68, 1.21)	(−1.84, 1.84)
(6–12) hours	−1.15	−0.27	−0.49	0.30	0.40	0.21	0.60
	(−2.77, 0.47)	(−0.72, 0.18)	(−1.41, 0.43)	(−1.03, 1.62)	(−1.08, 1.89)	(−1.43, 1.85)	(−1.46, 2.65)
≥12 h	−1.46	−0.18	−0.17	1.07	1.74	2.70**	2.07
	(−3.40, 0.48)	(−0.75, 0.40)	(−1.16, 0.83)	(−0.63, 2.76)	(−0.02, 3.50)	(0.69, 4.71)	(−0.61, 4.74)
Interaction between black patients and diversion level
X low diversion (<6 h)	−3.42	−1.03	−0.10	0.29	2.79	5.73*	2.53
	(−9.05, 2.20)	(−2.44, 0.38)	(−2.73, 2.53)	(−4.08, 4.65)	(−1.63, 7.22)	(0.41, 11.05)	(−3.96, 9.03)
X medium diversion (6–12) hours	−1.00	−0.87	2.58	3.52	5.01	2.69	0.63
	(−7.65, 5.64)	(−2.18, 0.45)	(−0.56, 5.72)	(−2.21, 9.24)	(−0.59, 10.62)	(−3.04, 8.41)	(−7.85, 9.12)
X high diversion (≥12 h)	0.22	−2.67**	−1.01	2.67	2.54	1.66	−0.44
	(−5.89, 6.33)	(−4.19, −1.16)	(−4.42, 2.40)	(−3.26, 8.60)	(−4.22, 9.31)	(−5.79, 9.11)	(−11.13, 10.26)
Control for tech access	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Control for treatment	NA	NA	NA	Yes	Yes	Yes	Yes
N	29 939	29 939	29 939	29 939	29 939	29 939	23 199

Nearest ED based on Google query of driving distance.
When compared to the reference group, the regression-adjusted difference is statistically significant at *p<0.05, **p<0.01.
CABG, coronary artery bypass graft; ED, emergency department; PCI, percutaneous coronary intervention.