Table 1 Characteristics of studies in children, immunocompromised and recently arrived immigrants from countries with high incidence of TB
Study ID (First author, year, country, and extent of TB burdenb) | Tests compared | Total number of participants tested with IGRA and TST | Mean (range or SD) or median age (IQR) in years | BCG vaccination [n, (%)] in population | Mean or median length of follow-up (years) | Method(s) for diagnosing TB |
|---|---|---|---|---|---|---|
Children | ||||||
 Diel 2011 [11], Germany  Low incidence | QFT-GIT vs. TST (5/10 mm) | 126 | Mean: 10.4 (SD: 4.3) | 45 (35.7%) | 2–4 | Chest x-ray, identification of AFB in sputum samples by bronchoscopy or lavage of gastric secretions, conventional culture of Mycobacterium tuberculosis, nucleic acid amplification and/or histopathology, assessment of preceding clinical suspicion of TB |
 Mahomed 2011 [13], South Africa  High incidence | QFT-GIT vs. TST (5 mm) | 5244 | NR (range: 12–18) | Yes: 4917 (93.8%); Unknown 281 (5.4%) | 3.8 | Two sputum samples for smear microscopy on two separate occasions. If any single sputum was smear positive, a mycobacterial culture, chest x-ray, and HIV test were performed |
 Metin Timur 2014 [14], Turkey  Intermediate incidence | QFT-GIT vs. TST (15 mm) | 81 | Mean: 7.9 (range: 0.5–16) | 69 (85.2%) | 3 | TST and QFT-GIT test positive in a child who had symptoms of TB disease and/or abnormal findings on chest radiograph, CT or proven M. tuberculosis culture, PCR or histo- pathological examination |
 Noorbakhsh 2011 [15], Iran  Intermediate incidence | QFT-G vs. TST (10 mm) | Not reported | NR (<20) | Not reported | 1 | Person diagnosed by an internist in the pulmonary and infectious ward of hospital. |
 Song 2014 [16], South Korea  High incidence | QFT-GIT vs. TST (10/15 mm) | 2982 | Mean: 15.1 (SD: 1.3) | 1,818 (61.0%) | 2 | NR |
Immunocompromised | ||||||
 Elzi 2011 [12], Switzerland (PLWHIV)  Low incidence | T-SPOT.TB vs. TST (5 mm) | 64 | Median: 33 (IQR: 31–42) | NR | 2 | NR |
 Kim 2011 [17], South Korea  (Post kidney transplantation)  High incidence | T-SPOT.TB vs. TST (5 mm) | 272 | NR (range: 40.4–46.0) | 215 (79%) | 1.17 (median) | Symptoms/signs, sputum AFB smear, and a CT scan |
 Kim 2015 [18], South Korea  (Rheumatoid diseases)a  High incidence | QFT-GIT vs. TST (5 mm) | 282 | Mean: 46.0 (SD: 15.4) | NR | 4 | Medical records of clinical features, sputum or tissue acid-fast bacilli staining and radiological findings |
 Lee 2009 [19], Taiwan  (Haemodialysis in end-stage renal  disease (ESRD))  High incidence | QFT-G vs. TST (10 mm) T-SPOT.TB vs. TST (10 mm) | 32 | Mean: 53.8 (range: 34.4–77.7) | 53 (82.8%) | 2 | Sputum TB smear, culture and chest radiography |
 Lee 2014 [22], South Korea  (Haematopoietic stem cell  transplantation recipients)  High incidence | QFT-GIT vs. TST (10/15 mm) | 169 | Mean: 42.3 (SD: 13.8) | 353 (90.7%) | 1.3 (median) | Chest x-ray, a sputum AFB smear and CT scan (pulmonary TB) |
 Lee 2015 [23], South Korea  (People with inflammatory arthritis)  High incidence | QFT-GIT vs. TST (10 mm) | 342 | Median: 40 (IQR: 30–53) | 236 (69.0%) | 3.5 (median) | Pulmonary TB was confirmed by sputum or bronchial washing culture |
 Milman 2011 [20], Denmark  (People with sarcoidosis)  Low incidence | QFT-G vs. TST (10 mm) | 41 | Median: 39 (IQR: 25–39) | 12 (27.3%) | 5 | Examinations of tissue specimens, Culture confirmed and polymerase chain reaction |
 Moon 2013 [21], South Korea  (Haematopoietic stem cell  transplantation candidates)  High incidence | QFT-GIT vs. TST (5 mm) | 244 | Mean: 47 (range: 35–55) | 201 (82%) | 0.8 (median) | NR |
 Sester 2014 [24], Various European  healthcare facilities  (PLWHIV, chronic renal failure, rheumatoid arthritis, solid-organ transplant or stem-cell transplantation)  Low incidence | QFT-GIT vs. TST (5 mm) T-SPOT.TB vs. TST (5 mm) | 1282 | NR | NR | 5 | Signs and symptoms of active TB. Culture confirmed and polymerase chain reaction |
 Sherkat 2014 [25], Iran  (Haemodialysis in end-stage renal disease (ESRD))  Intermediate incidence | T-SPOT.TB vs. TST (10 mm) | Not reported | Mean: 44 (SD: 15.5) | 12 (27.3%) | 1.75 | NR |
Recent arrivals from countries with a high incidence of TB | ||||||
 Harstad 2010 [26], Norway  Low incidence | QFT-GIT vs. TST (6/15 mm) | Not reported | NR | NR | 2.67 | NR |
 Kik 2010 [27], The Netherlands  Low incidence | QFT-GIT vs. TST (10/15 mm) T-SPOT.TB vs. TST (10/15 mm) | 339 | NR | 274 (80.8%) | 2 | Chest radiography, symptoms, smear and/or culture results |