Table 4 The association between NO₂, PM_2.5 and mortality in subgroups

Age < 75

2077 (19.3%)

1.301 (1.179, 1.434)

 < 0.001

1.824 (1.697, 1.96)

 < 0.001

0.845 (0.75, 0.953)

0.006

1.93 (1.777, 2.096)

 < 0.001

Age: [75, 85)

2282 (21.2%)

1.298 (1.215, 1.387)

 < 0.001

1.538 (1.471, 1.609)

 < 0.001

0.967 (0.894, 1.046)

0.402

1.554 (1.477, 1.635)

 < 0.001

Age: [85, 95)

3410 (31.7%)

1.105 (1.057, 1.155)

 < 0.001

1.231 (1.193, 1.27)

 < 0.001

0.969 (0.921, 1.019)

0.218

1.243 (1.2, 1.287)

 < 0.001

Age ≥ 95

2990 (27.8%)

1.02 (0.978, 1.065)

0.357

1.059 (1.026, 1.093)

 < 0.001

0.99 (0.945, 1.037)

0.674

1.062 (1.026, 1.099)

0.001

Female

6127 (56.9%)

1.119 (1.081, 1.158)

 < 0.001

1.225 (1.195, 1.256)

 < 0.001

1.001 (0.963, 1.041)

0.954

1.225 (1.191, 1.259)

 < 0.001

Male

4632 (43.1%)

1.113 (1.068, 1.16)

 < 0.001

1.276 (1.24, 1.314)

 < 0.001

0.947 (0.903, 0.992)

0.022

1.298 (1.257, 1.34)

 < 0.001

Urban

3746 (34.8%)

1.057 (1.018, 1.096)

0.004

1.18 (1.142, 1.219)

 < 0.001

0.962 (0.922, 1.003)

0.071

1.199 (1.155, 1.244)

 < 0.001

Rural

7013 (65.2%)

1.219 (1.172, 1.268)

 < 0.001

1.295 (1.264, 1.326)

 < 0.001

1.04 (0.996, 1.086)

0.079

1.284 (1.251, 1.317)

 < 0.001

Education:0 year

6868 (63.8%)

1.102 (1.067, 1.138)

 < 0.001

1.214 (1.187, 1.243)

 < 0.001

0.986 (0.952, 1.022)

0.455

1.219 (1.189, 1.25)

 < 0.001

Education:1–6 year

2928 (27.2%)

1.147 (1.088, 1.21)

 < 0.001

1.34 (1.289, 1.392)

 < 0.001

0.946 (0.89, 1.006)

0.077

1.363 (1.305, 1.423)

 < 0.001

Education: > 6 year

963 (9.0%)

1.15 (1.039, 1.273)

0.007

1.241 (1.152, 1.337)

 < 0.001

1.026 (0.916, 1.148)

0.661

1.231 (1.135, 1.337)

 < 0.001

Smoking: Heavy smoker

413 (3.8%)

1.372 (1.124, 1.675)

0.002

1.571 (1.367, 1.804)

 < 0.001

0.898 (0.699, 1.153)

0.398

1.636 (1.384, 1.934)

 < 0.001

Smoking: Light smoker

1485 (13.8%)

1.16 (1.076, 1.25)

 < 0.001

1.439 (1.356, 1.526)

 < 0.001

0.956 (0.88, 1.038)

0.282

1.459 (1.368, 1.556)

 < 0.001

Smoking: Former

1731 (16.1%)

1.092 (1.027, 1.161)

0.005

1.191 (1.141, 1.244)

 < 0.001

0.981 (0.916, 1.051)

0.594

1.198 (1.142, 1.257)

 < 0.001

Smoking: Never

7130 (66.3%)

1.111 (1.075, 1.148)

 < 0.001

1.227 (1.198, 1.256)

 < 0.001

0.985 (0.949, 1.022)

0.415

1.232 (1.201, 1.264)

 < 0.001

Alcohol: Heavy drinker

1127 (10.5%)

1.172 (1.068, 1.287)

0.001

1.397 (1.309, 1.492)

 < 0.001

0.966 (0.872, 1.07)

0.504

1.411 (1.314, 1.515)

 < 0.001

Alcohol: Moderate drinker

661 (6.1%)

1.115 (0.992, 1.253)

0.068

1.248 (1.141, 1.365)

 < 0.001

0.992 (0.87, 1.13)

0.9

1.251 (1.134, 1.381)

 < 0.001

Alcohol: Former

1502 (14.0%)

1.011 (0.946, 1.081)

0.742

1.249 (1.187, 1.314)

 < 0.001

0.872 (0.809, 0.94)

 < 0.001

1.303 (1.233, 1.378)

 < 0.001

Alcohol: Never

7469 (69.4%)

1.133 (1.098, 1.17)

 < 0.001

1.23 (1.202, 1.258)

 < 0.001

1.006 (0.97, 1.042)

0.761

1.228 (1.198, 1.259)

 < 0.001

Ability to exercise regularily: current

2712 (25.2%)

1.141 (1.083, 1.202)

 < 0.001

1.266 (1.216, 1.318)

 < 0.001

1.009 (0.952, 1.07)

0.763

1.262 (1.208, 1.32)

 < 0.001

Ability to exercise regularily: Former

1294 (12.0%)

1.003 (0.937, 1.074)

0.933

1.145 (1.09, 1.203)

 < 0.001

0.905 (0.837, 0.979)

0.013

1.181 (1.118, 1.247)

 < 0.001

Ability to exercise regularily: Never

6753 (62.8%)

1.143 (1.104, 1.184)

 < 0.001

1.272 (1.241, 1.303)

 < 0.001

0.993 (0.955, 1.033)

0.73

1.274 (1.241, 1.309)

 < 0.001

Marriage_status: Married

3399 (31.6%)

1.227 (1.159, 1.3)

 < 0.001

1.433 (1.377, 1.492)

 < 0.001

0.969 (0.908, 1.035)

0.35

1.447 (1.383, 1.513)

 < 0.001

Marriage_status:Not married

7360 (68.4%)

1.083 (1.051, 1.116)

 < 0.001

1.194 (1.168, 1.22)

 < 0.001

0.978 (0.946, 1.011)

0.189

1.202 (1.173, 1.23)

 < 0.001

Household income: < 4000

2634 (24.5%)

1.221 (1.141, 1.308)

 < 0.001

1.361 (1.304, 1.421)

 < 0.001

1.02 (0.945, 1.1)

0.617

1.355 (1.294, 1.42)

 < 0.001

Household income: < 10,000

2472 (23.0%)

1.122 (1.056, 1.194)

 < 0.001

1.279 (1.227, 1.333)

 < 0.001

0.964 (0.899, 1.033)

0.297

1.291 (1.235, 1.35)

 < 0.001

Household income: < 20,000

2393 (22.2%)

1.149 (1.089, 1.212)

 < 0.001

1.264 (1.214, 1.315)

 < 0.001

1.026 (0.968, 1.088)

0.387

1.255 (1.202, 1.31)

 < 0.001

Household income: ≥ 20,000

3260 (30.3%)

1.089 (1.043, 1.138)

 < 0.001

1.181 (1.142, 1.221)

 < 0.001

0.988 (0.94, 1.037)

0.618

1.186 (1.143, 1.231)

 < 0.001

BMI: < 18.5

3628 (33.7%)

1.073 (1.027, 1.121)

0.002

1.23 (1.189, 1.271)

 < 0.001

0.964 (0.919, 1.012)

0.137

1.242 (1.198, 1.288)

 < 0.001

BMI: < 25

6232 (57.9%)

1.121 (1.081, 1.161)

 < 0.001

1.262 (1.231, 1.293)

 < 0.001

0.966 (0.928, 1.006)

0.096

1.274 (1.24, 1.31)

 < 0.001

BMI: < 30

770 (7.2%)

1.251 (1.129, 1.386)

 < 0.001

1.228 (1.14, 1.322)

 < 0.001

1.12 (0.994, 1.262)

0.063

1.181 (1.085, 1.285)

 < 0.001

BMI: ≥ 30

129 (1.2%)

1.473 (1.042, 2.082)

0.028

1.548 (1.173, 2.044)

0.002

1.195 (0.812, 1.76)

0.367

1.457 (1.071, 1.981)

0.017

Region: central

2974 (27.6%)

1.174 (1.102, 1.251)

 < 0.001

1.246 (1.198, 1.296)

 < 0.001

0.981 (0.91, 1.056)

0.607

1.253 (1.198, 1.31)

 < 0.001

Region: eastern

3147 (29.2%)

1.269 (1.207, 1.335)

 < 0.001

1.263 (1.217, 1.311)

 < 0.001

1.151 (1.088, 1.217)

 < 0.001

1.217 (1.169, 1.267)

 < 0.001

Region: northeastern

904 (8.4%)

1.107 (1.022, 1.2)

0.013

0.98 (0.897, 1.071)

0.66

1.125 (1.035, 1.224)

0.006

0.943 (0.858, 1.035)

0.217

Region: northern

354 (3.3%)

1.227 (1.08, 1.394)

0.002

1.114 (1.038, 1.195)

0.003

1.15 (0.986, 1.341)

0.074

1.068 (0.981, 1.162)

0.128

Region: southern

2390 (22.2%)

1.027 (0.959, 1.1)

0.448

2.057 (1.906, 2.219)

 < 0.001

0.824 (0.766, 0.886)

 < 0.001

2.218 (2.044, 2.407)

 < 0.001

Region: southwestern

990 (9.2%)

0.941 (0.866, 1.024)

0.158

1.885 (1.755, 2.025)

 < 0.001

0.728 (0.668, 0.794)

 < 0.001

2.051 (1.904, 2.21)

 < 0.001

Self-reported respiratory disease: No

9718 (90.3%)

1.124 (1.093, 1.156)

 < 0.001

1.247 (1.223, 1.273)

 < 0.001

0.989 (0.958, 1.02)

0.487

1.251 (1.224, 1.279)

 < 0.001

Self-reported respiratory disease: Yes

884 (8.2%)

1.062 (0.971, 1.162)

0.188

1.219 (1.138, 1.305)

 < 0.001

0.934 (0.843, 1.035)

0.192

1.247 (1.155, 1.346)

 < 0.001

Self-reported cardiovascular disease: No

10,020 (93.1%)

1.118 (1.088, 1.15)

 < 0.001

1.253 (1.229, 1.278)

 < 0.001

0.98 (0.951, 1.011)

0.208

1.26 (1.233, 1.288)

 < 0.001

Self reported cardiovascular disease: Yes

568 (5.3%)

1.033 (0.919, 1.16)

0.589

1.074 (0.988, 1.168)

0.093

0.987 (0.867, 1.123)

0.84

1.078 (0.983, 1.183)

0.108

NO₂ < 16

5590 (52.0%)

1.036 (0.949, 1.131)

0.432

1.521 (1.47, 1.574)

 < 0.001

0.749 (0.681, 0.823)

 < 0.001

1.566 (1.512, 1.623)

 < 0.001

NO₂ ≥ 16

5169 (48.0%)

1.098 (1.054, 1.143)

 < 0.001

1.11 (1.082, 1.14)

 < 0.001

1.047 (1.003, 1.093)

0.037

1.1 (1.07, 1.131)

 < 0.001

PM_2.5 < 51

5466 (50.8%)

1.109 (1.061, 1.158)

 < 0.001

2.006 (1.895, 2.124)

 < 0.001

0.967 (0.923, 1.013)

0.156

2.026 (1.91, 2.149)

 < 0.001

PM_2.5 ≥ 51

5293 (49.2%)

1.054 (1.016, 1.094)

0.005

1.051 (1.018, 1.085)

0.002

1.038 (0.998, 1.08)

0.062

1.04 (1.005, 1.076)

0.025

Temperature mean: [ 0.132,15.1)

3587 (33.3%)

1.143 (1.095, 1.194)

 < 0.001

1.109 (1.077, 1.141)

 < 0.001

1.083 (1.031, 1.138)

0.001

1.082 (1.048, 1.118)

 < 0.001

Temperature mean: [15.083,17.8)

3587 (33.3%)

1.071 (1.02, 1.124)

0.005

1.254 (1.209, 1.3)

 < 0.001

0.96 (0.911, 1.011)

0.118

1.267 (1.219, 1.318)

 < 0.001

Temperature mean: [17.822,25.3]

3585 (33.3%)

1.094 (1.034, 1.156)

0.002

2.025 (1.918, 2.137)

 < 0.001

0.843 (0.793, 0.896)

 < 0.001

2.132 (2.014, 2.257)

 < 0.001

Temperature SD: [4.28, 8.17)

3588 (33.3%)

1.036 (0.987, 1.088)

0.151

1.708 (1.635, 1.785)

 < 0.001

0.876 (0.833, 0.922)

 < 0.001

1.762 (1.684, 1.844)

 < 0.001

Temperature SD: [8.17, 9.81)

3585 (33.3%)

1.128 (1.069, 1.19)

 < 0.001

1.288 (1.24, 1.338)

 < 0.001

0.982 (0.925, 1.042)

0.547

1.294 (1.242, 1.349)

 < 0.001

Temperature SD: [9.81,17.18]

3586 (33.3%)

1.227 (1.175, 1.282)

 < 0.001

1.174 (1.139, 1.21)

 < 0.001

1.134 (1.08, 1.191)

 < 0.001

1.128 (1.091, 1.168)

 < 0.001