Table 1 Overall demographic and clinical characteristics of test-positive and test-negative subjects, and population controls (for the case–control design 2) by autoimmune status

Gender = Male (%)

9666 (47.5)

9496 (48.2)

170 (25.6)

13,658 (39.4)

13,438 (40.2)

220 (17)

38,659 (47.5)

38,127 (48.1)

532 (24.5)

Age mean (sd)

65.5 (19.4)

65.6 (19.5)

64.5 (16.1)

54.8 (20.8)

54.8 (20.95)

56.9 (16.4)

65.5 (19.4)

65.5 (19.5)

66.2 (16.1)

Age class (years) (%)

 < 17

171 (0.8)

170 (0.9)

1 (0.2)

905 (2.6)

902 (2.7)

3 (0.2)

684 (0.8)

682 (0.9)

2 (0.1)

 [18–40)

1907 (9.4)

1868 (9.5)

39 (5.9)

7521 (21.7)

7353 (22)

168 (13)

7629 (9.4)

7512 (9.5)

117 (5.4)

 [40–70)

8622 (42.3)

8264 (42)

358 (53.8)

17,047 (49.1)

16,241 (48.6)

806 (62.1)

34,488 (42.4)

33,452 (42.2)

1036 (47.8)

 ≥ 70

9664 (47.5)

9397 (47.7)

267 (40.2)

9224 (26.6)

8904 (26.7)

320 (24.7)

38,613 (47.4)

37,599 (47.4)

1014 (46.7)

Geographic location (%)

 Lodi province (start of the outburst)

2939 (14.4)

2836 (14.4)

103 (15.5)

5185 (14.9)

5001 (15)

184 (14.2)

11,675 (14.3)

11,356 (14.3)

319 (14.7)

 City of Milan

7235 (35.5)

7025 (35.7)

210 (31.6)

13,188 (38)

12,761 (38.2)

427 (32.9)

29,185 (35.8)

28,437 (35.9)

748 (34.5)

 Milan province

10,190 (50)

9838 (49.9)

352 (52.9)

16,324 (47)

15,638 (46.8)

686 (52.9)

40,554 (49.8)

39,452 (49.8)

1102 (50.8)

Setting (%)

 Home

6122 (30.1)

5861 (29.8)

261 (39.2)

–

–

–

–

–

–

 Residential

3381 (16.6)

3319 (16.8)

62 (9.3)

–

–

–

–

–

–

 Residential followed by hospitalization

556 (2.7)

548 (2.8)

8 (1.2)

–

–

–

–

–

–

 Hospitalized

10,305 (50.6)

9971 (50.6)

334 (50.2)

–

–

–

–

–

–

Health status

 Non-hospitalized and alive

8292 (40.7)

7998 (40.6)

294 (44.2)

–

–

–

–

–

–

 Hospitalized and alive

7949 (39.0)

7692 (39.0)

257 (38.6)

–

–

–

–

–

–

 Deceased

4123 (20.2)

4009 (20.4)

114 (17.1)

–

–

–

–

–

–

Number of comorbidities (Excluded autoimmune diseases)

 None

8265 (40.6)

8105 (41.1)

160 (24.1)

18,870 (54.4)

18,457 (55.3)

413 (31.8)

36,658 (45)

36,131 (45.6)

527 (24.3)

 1–3

8951 (44)

8581 (43.6)

370 (55.6)

11,959 (34.5)

11,286 (33.8)

673 (51.9)

36,156 (44.4)

34,862 (44)

1294 (59.7)

 ≥ 4

3148 (15.5)

3013 (15.3)

135 (20.3)

3868 (11.1)

3657 (10.9)

211 (16.3)

8600 (10.6)

8252 (10.4)

348 (16)

 Comorbidities (%)

 Transplanted any time = Yes (%)

77 (0.4)

75 (0.4)

2 (0.3)

227 (0.7)

221 (0.7)

6 (0.5)

159 (0.2)

155 (0.2)

4 (0.2)

 Blood and Hematopoietic organs = Yes (%)

30 (0.1)

27 (0.1)

3 (0.5)

64 (0.2)

57 (0.2)

7 (0.5)

85 (0.1)

80 (0.1)

5 (0.2)

 HIV infection or AIDS = Yes (%)

72 (0.4)

72 (0.4)

0 (0)

224 (0.6)

220 (0.7)

4 (0.3)

261 (0.3)

259 (0.3)

2 (0.1)

 Tumor in first line treatment = Yes (%)

1024 (5)

923 (4.7)

101 (15.2)

2027 (5.8)

1869 (5.6)

158 (12.2)

3303 (4.1)

3023 (3.8)

280 (12.9)

 Tumor in follow-up, 1–5 years = Yes (%)

788 (3.9)

759 (3.9)

29 (4.4)

1128 (3.3)

1071 (3.2)

57 (4.4)

3153 (3.9)

3050 (3.8)

103 (4.7)

 Tumor in remission after 5 years = Yes (%)

1087 (5.3)

1038 (5.3)

49 (7.4)

1337 (3.9)

1269 (3.8)

68 (5.2)

4238 (5.2)

4088 (5.2)

150 (6.9)

 Type 1 diabetes = Yes (%)

28 (0.1)

28 (0.1)

0 (0)

79 (0.2)

76 (0.2)

3 (0.2)

58 (0.1)

54 (0.1)

4 (0.2)

 Type 2 diabetes = Yes (%)

2426 (11.9)

2357 (12)

69 (10.4)

2537 (7.3)

2434 (7.3)

103 (7.9)

7660 (9.4)

7433 (9.4)

227 (10.5)

 Complicated DM Type 1 and 2 = Yes (%)

423 (2.1)

408 (2.1)

15 (2.3)

527 (1.5)

503 (1.5)

24 (1.9)

750 (0.9)

722 (0.9)

28 (1.3)

 Hypercholesterolaemia = Yes (%)

2301 (11.3)

2216 (11.2)

85 (12.8)

2614 (7.5)

2495 (7.5)

119 (9.2)

9607 (11.8)

9306 (11.7)

301 (13.9)

 Arterial hypertension = Yes (%)

8187 (40.2)

7896 (40.1)

291 (43.8)

9454 (27.2)

9016 (27)

438 (33.8)

32,202 (39.6)

31,267 (39.5)

935 (43.1)

 Ischemic heart disease = Yes (%)

2364 (11.6)

2297 (11.7)

67 (10.1)

2744 (7.9)

2617 (7.8)

127 (9.8)

7497 (9.2)

7273 (9.2)

224 (10.3)

 Valvular heart disease = Yes (%)

475 (2.3)

458 (2.3)

17 (2.6)

678 (2)

647 (1.9)

31 (2.4)

1328 (1.6)

1287 (1.6)

41 (1.9)

 Cardiomyopathy with arrhythmia = Yes (%)

2310 (11.3)

2241 (11.4)

69 (10.4)

2614 (7.5)

2503 (7.5)

111 (8.6)

6850 (8.4)

6634 (8.4)

216 (10)

 Cardiomyopathy without arrhythmia = Yes (%)

1699 (8.3)

1641 (8.3)

58 (8.7)

2025 (5.8)

1941 (5.8)

84 (6.5)

5278 (6.5)

5129 (6.5)

149 (6.9)

 Chronic hearth failure = Yes (%)

1401 (6.9)

1346 (6.8)

55 (8.3)

1764 (5.1)

1680 (5)

84 (6.5)

3567 (4.4)

3463 (4.4)

104 (4.8)

 Peripheral artery disease = Yes (%)

595 (2.9)

573 (2.9)

22 (3.3)

820 (2.4)

784 (2.3)

36 (2.8)

1334 (1.6)

1290 (1.6)

44 (2)

 Venous diseases = Yes (%)

201 (1)

192 (1)

9 (1.4)

281 (0.8)

259 (0.8)

22 (1.7)

580 (0.7)

562 (0.7)

18 (0.8)

 Cerebrovascular disease = Yes (%)

822 (4)

799 (4.1)

23 (3.5)

932 (2.7)

884 (2.6)

48 (3.7)

1653 (2)

1607 (2)

46 (2.1)

 Thyroid diseases = Yes (%)

1137 (5.6)

783 (4)

354 (53.2)

2149 (6.2)

1357 (4.1)

792 (61.1)

4106 (5)

2872 (3.6)

1234 (56.9)

 Other endocrine diseases = Yes (%)

78 (0.4)

70 (0.4)

8 (1.2)

173 (0.5)

150 (0.4)

23 (1.8)

225 (0.3)

211 (0.3)

14 (0.6)

 Other autoimmune diseases = Yes (%)

359 (1.8)

22 (0.1)

337 (50.7)

601 (1.7)

47 (0.1)

554 (42.7)

1095 (1.3)

63 (0.1)

1032 (47.6)

 Epilepsy = Yes (%)

271 (1.3)

257 (1.3)

14 (2.1)

393 (1.1)

380 (1.1)

13 (1)

598 (0.7)

577 (0.7)

21 (1)

 Alzheimer and dementias = Yes (%)

669 (3.3)

655 (3.3)

14 (2.1)

579 (1.7)

562 (1.7)

17 (1.3)

989 (1.2)

968 (1.2)

21 (1)

 Parkinson and parkinsonisms = Yes (%)

310 (1.5)

305 (1.5)

5 (0.8)

287 (0.8)

279 (0.8)

8 (0.6)

616 (0.8)

596 (0.8)

20 (0.9)

 Nervous system diseases, others = Yes (%)

99 (0.5)

94 (0.5)

5 (0.8)

232 (0.7)

218 (0.7)

14 (1.1)

263 (0.3)

257 (0.3)

6 (0.3)

 Chronic hepatitis and cirrhosis = Yes (%)

433 (2.1)

413 (2.1)

20 (3)

705 (2)

666 (2)

39 (3)

1293 (1.6)

1248 (1.6)

45 (2.1)

 Digestive system diseases, others = Yes (%)

254 (1.2)

243 (1.2)

11 (1.7)

459 (1.3)

434 (1.3)

25 (1.9)

763 (0.9)

710 (0.9)

53 (2.4)

 COPD = Yes (%)

897 (4.4)

864 (4.4)

33 (5)

1089 (3.1)

1039 (3.1)

50 (3.9)

2433 (3)

2345 (3)

88 (4.1)

 RF or oxygen therapy = Yes (%)

97 (0.5)

91 (0.5)

6 (0.9)

151 (0.4)

142 (0.4)

9 (0.7)

221 (0.3)

207 (0.3)

14 (0.6)

 Asthma = Yes (%)

443 (2.2)

422 (2.1)

21 (3.2)

833 (2.4)

776 (2.3)

57 (4.4)

1369 (1.7)

1303 (1.6)

66 (3)

 CKD = Yes (%)

590 (2.9)

557 (2.8)

33 (5)

716 (2.1)

681 (2)

35 (2.7)

1464 (1.8)

1409 (1.8)

55 (2.5)

 Dialysis dependent CKD = Yes (%)

151 (0.7)

147 (0.7)

4 (0.6)

443 (1.3)

427 (1.3)

16 (1.2)

122 (0.1)

121 (0.2)

1 (0)

Autoimmune diseases

 Acquired autoimmune hemolytic anemia

–

–

10 (1.5)

–

–

11 (0.8)

–

–

19 (0.9)

 Systemic sclerosis

–

–

21 (3.2)

–

–

47 (3.6)

–

–

51 (2.4)

 Ankylosing spondylitis

–

–

13 (2)

–

–

22 (1.7)

–

–

42 (1.9)

 Myasthenia gravis

–

–

20 (3)

–

–

21 (1.6)

–

–

39 (1.8)

 Rheumatoid arthritis

–

–

167 (25.1)

–

–

223 (17.2)

–

–

479 (22.1)

 Psoriatic arthritis

–

–

69 (10.4)

–

–

139 (10.7)

–

–

284 (13.1)

 Systemic lupus erythematosus

–

–

16 (2.4)

–

–

38 (2.9)

–

–

57 (2.6)

 Sjögren disease

–

–

26 (3.9)

–

–

60 (4.6)

–

–

70 (3.2)

 Hashimoto’s disease

–

–

323 (48.6)

–

–

736 (56.7)

–

–

1128 (52.0)