Development and validation of a nomogram model for predicting the risk of pre-hospital delay in patients with acute myocardial infarction

Table 1 Comparison of related data between development group and validation group, n (%)

Variable	Category	Total	Development group	Validation group	P value
n		252	180	72
Sex (%)	Male	197 (78.2)	142 (78.9)	55 (76.4)	0.664
	Female	55 (21.8)	38 (21.1)	17 (23.6)
Age, mean (SD)		61.09 (14.55)	60.94 (14.82)	61.46 (13.94)	0.798
Killip grade (%)	1	195 (77.4)	141 (78.3)	54 (75.0)	0.914
	2	42 (16.7)	29 (16.1)	13 (18.1)
	3	10 (4.0)	7 (3.9)	3 (4.2)
	4	5 (2.0)	3 (1.7)	2 (2.8)
Monthly household income (%)	< 3000 yuan	125 (49.6)	82 (45.6)	43 (59.7)	0.125
	3000–5000 yuan	85 (33.7)	66 (36.7)	19 (26.4)
	> 5000 yuan	42 (16.7)	32 (17.8)	10 (13.9)
Number of stents placed, mean (SD)		1.47 (0.91)	1.40 (0.89)	1.64 (0.94)	0.059
Number of coronary artery lesions, mean (SD)		1.89 (0.79)	1.83 (0.79)	2.03 (0.79)	0.078
Combined with hypertension (%)	No	114 (45.2)	88 (48.9)	26 (36.1)	0.066
	Yes	138 (54.8)	92 (51.1)	46 (63.9)
Combined with cerebral infarction (%)	No	227 (90.1)	166 (92.2)	61 (84.7)	0.072
	Yes	25 (9.9)	14 (7.8)	11 (15.3)
Combined with hyperlipidemia (%)	No	214 (84.9)	156 (86.7)	58 (80.6)	0.221
	Yes	38 (15.1)	24 (13.3)	14 (19.4)
Diabetes mellitus (%)	No	164 (65.1)	121 (67.2)	43 (59.7)	0.259
	Yes	88 (34.9)	59 (32.8)	29 (40.3)
Combined with renal insufficiency (%)	No	227 (90.1)	162 (90.0)	65 (90.3)	0.947
	Yes	25 (9.9)	18 (10.0)	7 (9.7)
Combined digestive system diseases (%)	No	217 (86.1)	155 (86.1)	62 (86.1)	1
	Yes	35 (13.9)	25 (13.9)	10 (13.9)
Timi classification (%)	0	136 (54.0)	100 (55.6)	36 (50.0)	0.491
	1	15 (6.0)	11 (6.1)	4 (5.6)
	2	27 (10.7)	21 (11.7)	6 (8.3)
	3	74 (29.4)	48 (26.7)	26 (36.1)
Payment method (%)	Self-paid	17 (6.7)	11 (6.1)	6 (8.3)	0.525
	Medical insurance reimbursement	235 (93.3)	169 (93.9)	66 (91.7)
History of acute myocardial infarction (%)	No	242 (96.0)	175 (97.2)	67 (93.1)	0.126
	Yes	10 (4.0)	5 (2.8)	5 (6.9)
Time of onset (%)	Daytime	110 (43.7)	73 (40.6)	37 (51.4)	0.117
	Nighttime	142 (56.3)	107 (59.4)	35 (48.6)
Living alone (%)	No	227 (90.1)	162 (90.0)	65 (90.3)	0.947
	Yes	25 (9.9)	18 (10.0)	7 (9.7)
Type of residence (%)	Rural	94 (37.3)	67 (37.2)	27 (37.5)	0.967
	Town	158 (62.7)	113 (62.8)	45 (62.5)
Regular jobs (%)	No	170 (67.5)	120 (66.7)	50 (69.4)	0.671
	Yes	82 (32.5)	60 (33.3)	22 (30.6)
History of heart failure (%)	No	227 (90.1)	165 (91.7)	62 (86.1)	0.183
	Yes	25 (9.9)	15 ( 8.3)	10 (13.9)
Education level (%)	Junior high school and below	153 (60.7)	108 (60.0)	45 (62.5)	0.321
	Senior high school	45 (17.9)	36 (20.0)	9 (12.5)
	University and above	54 (21.4)	36 (20.0)	18 (25.0)
Marriage (%)	Married	228 (90.5)	165 (91.7)	63 (87.5)	0.114
	Divorce or widow	20 (7.9)	11 ( 6.1)	9 (12.5)
	Unmarried	4 (1.6)	4 (2.2)	0 (0.0)
Drinking (%)	No	177 (70.2)	125 (69.4)	52 (72.2)	0.663
	Yes	75 (29.8)	55 (30.6)	20 (27.8)
Smoking (%)	No	133 (52.8)	93 (51.7)	40 (55.6)	0.576
	Yes	119 (47.2)	87 (48.3)	32 (44.4)
Body mass index, mean (SD)		24.46 (3.35)	24.54 (3.37)	24.25 (3.33)	0.526
Combined with atrial fibrillation (%)	No	236 (93.7)	169 (93.9)	67 (93.1)	0.806
	Yes	16 (6.3)	11 (6.1)	5 (6.9)

Table 2 Results of univariate and multivariate Logistic regression analysis on risk of pre-hospital delay in development group

Variables	Univariate logistic regression		Multivariate logistic regression
	OR (95%CI)	P value	OR (95%CI)	P value
BMI	0.956 (0.867, 1.050)	0.35
Killip Grade 1	Reference
Killip Grade 2	1.061 (0.429, 2.464)	0.894
Killip Grade 3	3.143 (0.666, 16.536)	0.145
Killip Grade 4	4.714 (0.440, 103.073)	0.211
Timi Grade 0	Reference
Timi Grade 1	1.855 (0.501, 6.615)	0.337
Timi Grade 2	0.890 (0.294, 2.420)	0.826
Timi Grade 3	1.012 (0.474, 2.109)	0.975
Living alone	3.059 (1.138, 8.476)	0.027	4.654 (1.386, 16.957)	0.015
Daytime onset	Reference
Nighttime onset	2.831 (1.434, 5.853)	0.004	2.200 (0.968, 5.188)	0.064
Combined with atrial fibrillation	1.875 (0.520, 6.497)	0.317
Combined with hypertension	2.862 (1.493, 5.649)	0.002	1.990 (0.906, 4.473)	0.089
Combined with hyperlipidemia	2.467 (1.024, 5.957)	0.042	3.151 (1.095, 9.373)	0.035
Have a regular job	0.791 (0.395, 1.541)	0.497
Number of diseased coronary artery	1.109 (0.743, 1.656)	0.61
Marital status: married	Reference
Marriage: Divorced or widowed	0.792 (0.168, 2.864)	0.739
Marriage: Unmarried	0.704 (0.034, 5.648)	0.764
Prior history of AMI	3.361 (0.542, 26.068)	0.191
Family monthly income < 3000 yuan	Reference
The monthly income of the family = 3000–5000 yuan	0.922 (0.449, 1.872)	0.822
Family monthly income > 5000 yuan	1.560 (0.660, 3.636)	0.304
Type of residence: town	0.387 (0.201, 0.737)	0.004	0.576 (0.258, 1.281)	0.175
Complicated with cerebral infarction	1.691 (0.533, 5.112)	0.353
Age	1.043 (1.020, 1.069)	< 0.001	1.034 (1.004, 1.065)	0.027
Complicated with renal insufficiency	1.845 (0.668, 4.959)	0.225
Complicated with diabetes	3.211 (1.662, 6.278)	0.001	3.208 (1.466, 7.228)	0.004
Education level is junior high school or below	Reference
High school education	1.669 (0.766, 3.610)	0.193
Education level is university or above	0.417 (0.146, 1.035)	0.076
Smoking	0.404 (0.207, 0.771)	0.007	0.682 (0.279, 1.652)	0.395
Complicated with digestive system diseases	2.733 (1.154, 6.533)	0.022	3.937 (1.433, 11.236)	0.009
Complicated with heart failure	1.490 (0.478, 4.355)	0.471
Female sex	2.737 (1.309, 5.753)	0.007	1.419 (0.531, 3.776)	0.482
Drinking	0.841 (0.413, 1.659)	0.622
Payment method: medical insurance reimbursement	1.252 (0.347, 5.886)	0.747
Number of stents placed	1.300 (0.916, 1.856)	0.142

AMI: Acute myocardial infarction; BMI: Body mass index; OR: Odds ratio.