Table 1 Baseline characteristics of the exposed and unexposed cohorts

Sex, n (%)

 Male

207,514 (45.3)

823,988 (45.3)

 Female

250,633 (54.7)

994,941 (54.7)

Age (years)

 Mean (SD)

43.6 (17.1)

42.8 (18.0)

Age categories, n (%)

 18–29

113,618 (24.8)

478,811 (26.3)

 30–39

94,499 (20.6)

377,117 (20.7)

 40–49

87,707 (19.1)

348,335 (19.2)

 50–59

84,454 (18.4)

327,230 (18.0)

 60–69

41.841 (9.1)

153,227 (8.4)

  ≥ 70

36,028 (7.9)

134,209 (7.4)

Ethnicity, n (%)

 White

295,067 (64.4)

1,079,656 (59.4)

 South Asian

55,792 (12.2)

192,600 (10.6)

 Black

19,226 (4.2)

86,040 (4.7)

 Mixed ethnicity

7066 (1.5)

34,134 (1.9)

 Other

6614 (1.4)

33,873 (1.9)

 Missing

74,382 (16.2)

392,626 (21.6)

BMI

 Mean (SD)

27.6 (6.3)

26.8 (6.1)

 Median (IQR)

26.7 (23.3–30.9)

25.8 (22.5–29.8)

BMI categories, n (%)

 Underweight (< 18.5 kg/m²)

12,038 (2.6)

59,644 (3.3)

 Normal weight (18.5–25 kg/m²)

136,480 (29.8)

594,657 (32.7)

 Overweight (25–30 kg/m²)

131,076 (28.6)

473,031 (26.0)

 Obese (> 30 kg/m²)

116,836 (25.5)

366,198 (20.1)

 Missing

61,717 (13.5)

325,379 (17.9)

Smoking status, n (%)

 Never smoked

168,415 (36.8)

657,775 (36.2)

 Ex-smoker

167,507 (36.6)

548,695 (30.2)

 Current smoker

101,351 (22.1)

482,322 (26.5)

 Missing

20,874 (4.6)

130,137 (7.2)

Exposure to selected infection, n (%)

 All infections

2354 (0.5)

9098 (0.5)

 EBV

153 (0.0)

579 (0.0)

 CMV

123 (0.0)

327 (0.0)

 HHV-6

0 (0.0)

4 (0.0)

 HTLV-1

0 (0.0)

10 (0.0)

 Hepatitis C virus

784 (0.2)

4161 (0.2)

 Influenza A virus

968 (0.2)

2911 (0.2)

 Parvovirus B19

282 (0.1)

947 (0.1)

Exposure to selected medication, n (%)

 All medications

821 (0.2)

2552 (0.1)

 Procainamide

0 (0.00)

2 (0.0)

 Hydralazine

218 (0.1)

753 (0.0)

 Quinidine

26 (0.0)

92 (0.0)

 Isoniazid

581 (0.1)

1724 (0.1)