Skip to main content

Table 2 Outcome Chi-Square test

From: Artificial intelligence in Emergency Medical Services dispatching: assessing the potential impact of an automatic speech recognition software on stroke detection taking the Capital Region of Denmark as case in point

Characteristic

Stroke detected

Stroke not detected

Stroke relevant criteria + “A” response

Stroke relevant criteria + no “A” response

Stroke nonrelevant criteria

N

%

Residuals

N

%

Residuals

N

%

Residuals

Total

4773

3613

52.75%

60.09%

1200

588

13.26%

9.78%

1861

1134

20.57%

18.86%

Type

 Ischaemic

4345

3288

48.02%

54.68%

0.8664729

1.730522

1117

543

12.34%

9.03%

2.9572745

1.631358

1629

981

18.00%

16.31%

− 5.4382222

− 5.045376

 Haemorrhagic

428

325

4.73%

5.40%

− 0.8664728

− 1.730522

83

45

0.92%

0.75%

− 2.9572745

− 1.631358

232

153

2.56%

2.54%

5.4382222

5.045376

Sex

 Male

2663

2008

29.43%

33.39%

4.9358538

3.834136

628

294

6.94%

4.89%

− 0.7527075

− 1.826033

950

586

10.50%

9.75%

− 2.2267499

− 1.418067

 Female

2110

1605

23.32%

26.68%

− 4.9358538

− 3.834136

572

294

6.32%

4.89%

0.7527075

1.826033

911

548

10.07%

9.11%

2.2267499

1.418067

EMS number

 1-1-2

3566

2761

39.41%

45.92%

35.486025

23.923099

427

279

4.72%

4.64%

− 16.285076

− 9.024334

1106

765

12.22%

12.72%

2.139238

2.406850

 1813-Medical Helpline

1207

852

13.33%

12.17%

− 35.486025

− 23.923099

773

309

8.54%

5.14%

16.285076

9.024334

755

369

8.34%

6.14%

− 2.139238

− 2.406850

Year

 2016

1401

1062

14.48%

17.66%

− 3.6227039

− 2.4569773

451

232

4.98%

3.86%

5.2774675

4.9156658

615

369

6.80%

6.14%

2.1207352

1.5869673

 2017

1605

1208

17.74%

20.09%

0.5151980

0.9909348

401

185

4.43%

3.08%

0.0250515

− 0.8053347

627

369

6.93%

6.14%

0.3147488

− 0.3226088

 2018

1767

1343

19.53%

22.33%

2.9925059

1.3842896

348

171

3.85%

2.84%

− 5.1233044

− 3.9190487

619

396

6.84%

6.59%

− 2.3588767

− 1.2040795

Weekday

 Week

3278

2506

36.22%

41.68%

8.381580

4.336712

719

384

7.95%

6.39%

− 3.716612

− 1.041430

1275

805

14.09%

13.39%

3.868071

2.999783

 Weekend

1495

1107

16.52%

18.41%

− 8.381580

− 4.336712

481

204

5.32%

3.39%

3.716612

1.041430

586

329

6.48%

5.48%

− 3.868071

− 2.999783

Treatment*

1152

1091

12.73%

18.14%

15.023994

9.230893

94

82

1.04%

1.36%

− 10.276163

− 6.988008

293

269

3.24%

4.47%

− 3.282012

− 1.895487

 Thrombolysis

1041

1016

11.51%

16.89%

15.887928

10.410536

75

73

0.83%

1.21%

− 9.901901

− 6.665477

222

213

2.45%

3.54%

− 5.389991

− 4.144533

 Reperfusion

168

146

1.86%

2.43%

7.3690592

4.7924906

8

8

0.09%

0.13%

− 4.209392

− 2.6258701

39

34

0.43%

0.57%

− 0.9567605

− 0.3453236

 Endovascular

14

13

0.15%

0.22%

− 3.1609477

− 3.108757

5

3

0.06%

0.05%

− 0.5315617

− 0.343197

25

19

0.28%

0.32%

5.5483350

5.068036

 Surgical

14

8

0.15%

0.13%

− 2.6579592

− 3.9074732

4

2

0.04%

0.03%

− 0.7672481

− 0.6252947

19

17

0.21%

0.28%

3.8412820

5.1342675

 Thrombectomy

178

158

1.97%

2.63%

6.8198305

4.6608318

13

10

0.14%

0.17%

− 3.6134411

− 2.4740986

43

37

0.48%

0.62%

− 0.9978678

− 0.4347634

Characteristic

Missing criteria

Chi-Square test

Cramer’s V

Pairwise comparison

N

%

Residuals

X-Squared

Df

p-value

Estimate

[Low. CI.; Upr. CI]

Adj. sig. level

Critical

z-value

Total

1215

678

13.43%

11.28%

Type

 Ischaemic

1129

628

12.48%

10.44%

2.2363844

2.028612

35.762

27.903

3

= 8.406e−08

3.807e−06

0.0629 [0.0401; 0.0819]

0.0681 [0.0397; 0.0913]

0.00625

− 2.734269

 Haemorrhagic

91

50

1.01%

0.83%

− 2.2363844

− 2.028612

Sex

 Male

586

333

6.48%

5.54%

− 3.8390984

− 2.467792

28.702

15.911

3

= 2.587e−06

0.01183

0.0563 [0.0332; 0.0752]

0.0514 [0.0212; 0.0740]

0.00625

− 2.734269

 Female

629

345

6.95%

5.74%

3.8390984

2.467792

EMS number

 1-1-2

81

66

0.90%

1.10%

− 38.299051

− 31.542421

2098.6

1189.3

3

< 2.2e−16

2.2e−16

0.4816 [0.4607; 0.5020]

0.4447 [0.4191; 0.4697]

0.00625

− 2.734269

 1813-Medical Helpline

1134

612

12.53%

10.18%

38.299051

31.542421

Year

 2016

340

176

3.76%

2.93%

− 2.4591338

− 2.7748033

55.028

38.962

6

= 4.575e−10

7.281e07

0.0551 [0.0375; 0.0674]

0.0569 [0.0344; 0.0715]

0.0416667

− 2.86526

 2017

388

219

4.29%

3.64%

− 1.1524637

− 0.3789986

 2018

487

283

5.38%

4.71%

3.5109012

3.0261982

Weekday

 Week

582

347

6.43%

5.77%

− 13.161698

− 9.446623

207.03

94.963

3

< 2.2e−16

2.2e16

0.1513 [0.1299; 0.1712]

0.1257 [0.0989; 0.1497]

0.00625

− 2.734269

 Weekend

633

331

6.99%

5.50%

13.161698

9.446623

Treatment*

123

118

1.36%

1.96%

− 7.886774

− 5.385627

260.66

106.72

3

< 2.23−16

2.2e16

0.1697 [0.1484; 0.1897]

0.1332 [0.1065; 0.1573]

0.00625

− 2.734269

 Thrombolysis

111

110

1.23%

1.83%

− 7.025162

− 4.733407

270.13

117.16

3

< 2.2e−16

2.2e16

0.1728 [0.1515; 0.1928]

0.1396 [0.1130; 0.1638]

0.00625

− 2.734269

 Reperfusion

2

2

0.02%

0.03%

− 5.4690676

− 4.5272438

67.651

33.67

3

< 2.2e−16†

1.589e09†

0.0865 [0.0644; 0.1059]

0.0748 [0.0467; 0.0982]

0.00625

− 2.734269

 Endovascular

3

2

0.03%

0.03%

− 1.4200864

− 1.132402

31.165

25.942

3

= 1.056e−05†

8.998e05†

0.0587 [0.0357; 0.0777]

0.0657 [0.0370; 0.0888]

0.00625

− 2.734269

 Surgical

6

4

0.07%

0.07%

0.1015225

0.2872599

15.579

27.909

3

= 0.003068†

2.472e05†

0.0415 [0.0168; 0.0599]

0.0681 [0.0397; 0.0913]

0.00625

− 2.734269

 Thrombectomy

5

4

0.06%

0.07%

− 5.2089195

− 4.3553056

57.584

31.176

3

= 1.929e−12

2.142e08†

0.0798 [0.0575; 0.0991]

0.0720 [0.0438; 0.0953]

0.00625

− 2.734269

  1. “Italic” numbers indicate the subgroup analysis of stroke patients with a time-to-call < 4.5 h. “Bold” numbers indicate the difference to the initial analysis
  2. *A patient that received multiple treatments was considered individually for the individual treatments, but cumulated for the total number of treatments
  3. Results from the Fisher’s Exact test, due to the small number of < 5 within the group