Table 3. Multivariate model (logistic and Poisson) estimates of the odds and incidence rate ratios for TB, LTBI prevalence, and LTBI conversion*.
| Variable | Odds ratio (95% CI) for prevalence |
Incidence rate ratio (95% CI) for TST conversion | |
|---|---|---|---|
| TB | LTBI | ||
| TB incidence rate in the country of origin of the immigrants (per 105 p-y) | |||
| <25 | 1 (reference category) | 1 (reference cat) | 1 (reference category)† |
| 25–49 | 2.9 (0.9–9.3) | 2.0 (1.6–2.6) | 0.5 (0.1–4.1)† |
| 50–99 | 5.3 (1.6–17.2) | 1.6 (1.2–2.1) | 0.7 (0.1–6.5)† |
| 100–299 | 4.9 (1.6–15.2) | 2.6 (2.1–3.3) | 1.3 (0.2–9.3)† |
|
>300 |
4.6 (1.4–14.9) |
2.2 (1.7–2.9) |
1.4 (0.2–11.9)† |
| Sex | |||
| F | 1 (reference category) | 1 (ref category) | 1 (reference category) |
| M |
1.5 (1.3–1.8) |
1.1 (1.0–1.2) |
0.9 (0.6–1.3) |
| Time elapsed since immigration, y | |||
| <3 | 1 (reference category) | 1 (ref cat) | 1 (reference category) |
| 3–6 | 1.1 (0.9–1.3) | 1.1 (1.0–1.2) | 0.8 (0.4–1.5) |
| 7–9 | 1.1 (0.9–1.3) | 1.2 (1.1–1.3) | 0.5 (0.3–1.0) |
|
>10 |
0.9 (0.6–1.2) |
1.2 (1.1–1.4) |
0.4 (0.2–0.9) |
| Age, y, at test | |||
| <20 | 1 (reference category) | 1 (reference category) | 1 (reference category) |
| 20–29 | 1.4 (1.0–2.2) | 1.9 (1.7–2.2) | 1.0 (0.4–3.0) |
| 30–40 | 2.4 (1.6–3.5) | 3.1 (2.8–3.5) | 1.2 (0.4–3.5) |
| >40 | 4.3 (2.9–6.4) | 3.1 (2.7–3.5) | 1.0 (0.3–3.1) |
*The effects of the variables reported in the table were mutually adjusted. TB, tuberculosis; LTBI, latent TB infection; p-y, person-years. †Incidence rate ratio for tuberculin skin test conversion (95% CI): 1.21 (1.07–1.36) for an increase of 50 cases/105 p-y.