Table 2 Demographics of the unexposed individuals

Age (years), median (range)

64

(45-87)

70

(25-93)

0.81

Male, n (%)

5

(38)

70

(52)

0.36

Ethnicity, n (%)

  White Caucasian

13

(100)

136

(100)

Country of birth

  UK born

9

(69)

126

(93)

0.18

0.006

  Other

4

(31)†

10

(7.4)

  Years since immigration, median (range)

43

(21-62)

52

(8-61)

Ever visited a high prevalence country, n (%)

4

(31)

47

(35)

0.84

  Years since last visit, median (range)

8.5

(0-40)

5.5

(0-60)

Ever resident in a high prevalence area >6/52, n (%)

2

(15)

27

(20)

0.64

Occupation: healthcare, prison, lab n (%)‡

4

(31)

18

(13)

0.09

BCG (history or scar), n (%)

  Yes

7

(54)

66

(49)

0.73

  No

4

(31)

44

(33)

  Unknown

2

(15)

26

(19)

Medical history, n (%)

  Comorbidity known to be associated with TB§

0

(0)

21

(16)

0.22

  Immunosuppresive medications∥

4

(31)

12

(9.2)

4.6

0.015

  Ever known to be exposed to TB

4

(31)

26

(19)

0.32

  Ever had treatment for tuberculosis

2

(15)

2

(1.5)

12

0.003