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Table 1 Pooled yields among subgroups for all active TB, confirmed active TB, and LTBI

From: The yield of tuberculosis contact investigation in low- and middle-income settings: a systematic review and meta-analysis

Subgroups

n

Pooled % yield for all active TB (95% confidence interval)

n

Pooled % yield for confirmed active TB (95% confidence interval)

n

Pooled % yield for LTBI (95% confidence interval)

WHO Geographic regions

 AFR

37

3.43% (2.91–3.94, I2 97.09%)

27

1.97% (1.62–2.31, I2 94.58%)

15

44.14% (32.52–55.76, I2 99.62%)

 AMR

12

2.68% (1.95–3.41, I2 94.70%)

5

4.77% (2.02–7.51, I2 78.37)

6

56.74% (45.78–67.69, I2 98.31%)

 EMR

10

3.11% (2.33–3.90, I2 97.29%)

7

2.98% (2.13–3.82, I2 94.48%)

6

39.43% (27.23–51.62, I2 95.94%)

 EUR

3

2.30% (1.69–2.91)*

1

1.73% (1.05–2.83)*

2

38.44% (36.06–40.82)*

 SEAR

12

4.81% (3.42–6.21, I2 93.53%)

8

2.93% (1.59–4.27, I2 94.77%)

7

45.63% (26.66–64.60, I2 99.31%)

 WPR

14

1.17% (0.75–1.59, I2 98.58%)

10

0.94% (0.42–1.46, I2 99.04%)

6

32.58% (23.38–41.79, I2 97.90%)

World Bank income classification

 Low-income

28

3.00% (2.49–3.52, I2 97.70%)

21

1.97% (1.5–2.44, I2 97.04%)

13

46.89% (34.23–59.54, I2 99.67%)

 Lower middle-income

30

3.29% (2.74–3.84, I2 96.83%)

21

2.23% (1.69–2.76, I2 95.62%)

16

44.85% (34.57–55.13, I2 98.79%)

 Upper middle-income

30

2.22% (1.86–2.58, I2 97.52%)

16

1.78% (1.40–2.16, I2 96.73%)

13

39.34% (32.15–46.54, I2 98.73%)

Year started data collection

 Pre WHO guideline

63

2.77% (2.47–3.08, I2 97.97%)

38

1.99% (1.67%-2.31%, I2 98.34%)

39

45.22% (39.25–51.19, I2 99.40%)

 Post WHO guideline

25

3.08% (2.49–3.68, I2 96.33%)

20

2.10% (1.57–2.64, I2 95.09%)

3

25.80% (18.19–33.40)*

HIV status

 Positive contacts

9

8.95% (5.49–12.41, I2 80.53%)

5

6.71% (2.15–11.27, I2 89.11%)

0

N/A

Sputum smear status of index case

 Positive sputum smear index

5

8.30% (3.88–12.73, I2 85.36%)

N/A

N/A

N/A

N/A

MDR-TB

 Contacts of MDR-TB

13

4.69% (3.26–6.13, I2 94.30%)

10

3.43% (2.05–4.82, I2 90.28%)

7

37.53% (24.22–50.84, I2 95.99%)

Location of contact investigation

 Community-based

36

2.34% (1.96–2.72, I2 97.89%)

28

2.14% (1.72–2.55, I2 97.96%)

17

46.67% (36.86–56.49, I2 99.64%)

 Clinic-based

38

3.44% (2.96–3.93, I2 97.93%)

24

1.90% (1.37–2.43, I2 98.03%)

20

40.15% (32.81–47.49, I2 98.18%)

  1. AFR Africa, AMR Americas, EMR Eastern Mediterranean, EUR Europe, SEAR South-East Asia, WPR Western Pacific
  2. *Due to small study size it was not possible to assess heterogeneity