Characterization of prehospital time delay in primary percutaneous coronary intervention for acute myocardial infarction: analysis of geographical infrastructure-dependent and -independent components

Table 2 Factors associated with prolongation of pretransport time, ODT, and TIT

	Pretransport time > 43 min			ODT > 104 min			TIT > 185 min
	OR	95% CI	P value	OR	95% CI	P value	OR	95% CI	P value
Age ≤ 64 years	1	[Ref.]		1	[Ref.]		1	[Ref.]
65–74 years	1.46	0.87–2.44	0.15	1.21	0.76–1.91	0.42	1.76	1.13–2.74	0.01*
≥ 75 years	1.88	1.14–3.10	0.01*	1.86	1.19–2.91	< 0.01*	2.37	1.54–3.65	< 0.01*
Women	0.74	0.45–1.23	0.25	0.72	0.45–1.13	0.16	0.85	0.55–1.31	0.45
Recurrent MI	1.21	0.65–2.26	0.55	0.96	0.54–1.71	0.90	1.22	0.70–2.12	0.48
No witness	1.46	0.97–2.20	0.07	1.69	1.17–2.44	< 0.01*	1.52	1.07–2.17	0.02*
Onset in winter	0.62	0.41–0.94	0.03*	0.64	0.44–0.93	0.02*	0.88	0.61–1.26	0.47
Onset on weekends/holiday	1.02	0.66–1.58	0.93	1.03	0.69–1.54	0.89	1.14	0.77–1.67	0.52
Onset at night	1.70	1.12–2.57	0.01*	1.36	0.93–1.98	0.11	1.44	1.00–2.08	< 0.05*
Killip class 3/4 on arrival	0.88	0.49–1.57	0.67	1.14	0.66–1.94	0.64	1.52	0.90–2.55	0.11
No EMS call				2.92	1.91–4.49	< 0.01*	3.22	2.12–4.87	< 0.01*
Medical region and transport way
Urban (direct admission)	1	[Ref.]		1	[Ref.]		1	[Ref.]
Rural (direct admission)	1.15	0.72–1.82	0.56	1.17	0.77–1.77	0.47	1.14	0.75–1.72	0.54
Urban (inter-facility transfer)	2.94	0.66–13.02	0.16	2.73	1.27–5.85	< 0.01*	1.67	0.80–3.48	0.17
Rural (inter-facility transfer)	1.74	0.91–3.33	0.09	8.04	4.41–14.68	< 0.01*	3.58	2.12–6.05	< 0.01*

Adjusted odds ratio (OR) and 95% confidence interval (CI) from logistic regression analysis indicating the likelihood of pretransport time > 43 min (median pretransport time) in Ambulance Transfer groups, ODT (onset-to-door time) > 104 min (median ODT), and TIT (total ischemic time) > 185 min (median TIT). OR > 1 indicates increased odds of prolongation of each time component. Respective reference categories = age ≤ 64 years, male gender, first occurrence of MI, presence of a witness, onset in summer, onset in the daytime, Killip class 1/2 on arrival, EMS call, and urban medical region (direct admission). CPC, cerebral performance category; MI, myocardial infarction; Daytime, 6:00 a.m–6:00 p.m; Nighttime, 6:00 p.m–6:00 a.m; urban medical regions, Sapporo, Kamikawa Chubu, and Minami Oshima medical regions; rural medical regions, regions outside the urban medical regions
* P < 0.05

ISSN: 1476-072X