Summary of rates of conversions and reversions in serial testing studies (N=8)
| Study | Duration between testing | TST converters, n/N (%) | IGRA converters, n/N (%) | IGRA reverters, n/N (%) |
| High TB incidence countries | ||||
| Pai, 200615 | 18 months | 6/147 (4.1%) | 17/147 (11.6%) | 7/38 (18.4%) |
| Joshi, 200958 | 6 months | – | 11/57 (19%) | 6/22 (27%) |
| 6 months (6–12 months) | – | 11/52* (21%) | 11/27† (40%) | |
| Moderate and low TB incidence countries | ||||
| Pollock, 200964 | 1–7 months | – | 2/43‡ (4.6%) | – |
| Zwerling, 200959 | 1 year | 0/57 (0%) | 4/56 (7.14%) | 4/5 (80%) |
| Yoshiyama, 200960 | 2 and 4 years | – | 5/277 (1.8%) | 13/32 (41%) |
| Chee, 200961 | 1 year | 0/18‡ | 9/182 (4.9%) | – |
| Lee, 200962 | 1 year | 16/75 (21.3%) | 21/146 (14.4%) | – |
| Belknap, 201063 | 6 months | 4/1202 (0.3%) | TSPOT 44/1117 (3.9%) QFT-GIT 44/1169 (3.8%) | TSPOT 36/68 (52.9%) QFT-GIT 20/50 (40%) |
| Costa, 201020 | 1–2.5 years | 98/199 (49.2%) | 51/462 (11%) | 46/208 (22.1%) |
| Ringshausen, 201021 | 18 weeks | (baseline only) | 3/162 (1.9%) | 6/18 (33.3%) |
All conversions/reversions using simple negative/positive definition.
↵* Denominator includes only participants negative at 6 months.
↵† Denominator includes only participants positive at 6 months.
↵‡ Denominator includes only baseline concordant negatives.
IGRA, interferon-gamma release assay; PPD, purified protein derivative; TB, tuberculosis; TST, tuberculin skin test.