Table 2.
Incidence rate ratio of TB according to selected socio-demographic characteristics in Michigan, 2004–2012
| Variable | Clustered cases | Non-clustered cases | ||
|---|---|---|---|---|
| N | IRR (95% CI) | N | IRR (95% CI) | |
| 479 | 775 | |||
| Race | ||||
| White | 107 | Ref. | 312 | Ref. |
| Black | 296 | 24.6 (15.5, 38.8) | 229 | 7.7 (5.3, 11.1) |
| Asian | 76 | 18.6 (10.5, 32.9) | 234 | 23.5 (16.3, 35.8) |
| Nativity | ||||
| U.S.-born | 359 | Ref. | 335 | Ref. |
| Foreign-born | 117 | 10.0 (6.6, 15.2) | 440 | 7.0 (5.0, 9.8) |
| 3 missing | ||||
| Gender | ||||
| Male | 313 | Ref. | 437 | Ref. |
| Female | 166 | 0.61 (0.41, 0.91) | 338 | 0.74 (0.54, 1.0) |
| Age | ||||
| 18–64 Years | 414 | Ref. | 525 | Ref. |
| 65+ Years | 65 | 0.83 (0.54, 1.3) | 250 | 2.6 (1.9, 3.5) |
Classifications of race, age, gender, nativity, and site of TB disease were defined based on Report of Verified Case of TB form developed by the Centers for Disease Control and Prevention
Models based on multivariable negative binomial regression models
Clustered and non-clustered cases were modeled separately with all four demographic characteristics included in models: race, nativity, gender, and age
IRR incidence rate ratio
Ref. reference group