Table 1.
Observed and expected tuberculosis case counts by select demographic and risk factor characteristics for January-December 2009, United States
| Observed Case Count | Expected Case Count (95% Prediction Interval) |
Case Count Difference* | Percentage of Expected |
P value | |
|---|---|---|---|---|---|
| Total | 11545 | 12539 (12233 - 12853) | -994 | -7.9 | <.001 |
| Country of origin | |||||
| Foreign-born | 6854 | 7709 (7318 - 8120) | -855 | -11.1 | <.001 |
| U.S.-born | 4571 | 4918 (4661 - 5190) | -347 | -7.1 | .005 |
| Unknown | 120 | 21 (10 - 48) | 99 | 471.4 | .020 |
| For foreign-born, length of stay in United States | |||||
| < 2 years | 1432 | 1872 (1590 - 2204) | -440 | -23.5 | <.001 |
| > = 2 years | 4712 | 5197 (4865 - 5551) | -485 | -9.3 | .001 |
| Unknown | 710 | 684 (599 - 781) | 26 | 3.8 | .587 |
|
For foreign-born, country of origin according to implementation of 2007 immigration technical instructions (TI) |
|||||
| TI countries | 2993 | 3384 (3095 - 3699) | -391 | -11.6 | .002 |
| Non-TI countries | 3861 | 4325 (4044 - 4625) | -464 | -10.7 | <.001 |
| Race/ethnicity | |||||
| Hispanic | 3380 | 3953 (3563 - 4385) | -573 | -14.5 | <.001 |
| Non-Hispanic American Indian |
102 | 121 (100 - 148) | -19 | -15.7 | .151 |
| Non-Hispanic Asian |
3192 | 3355 (3093 - 3639) | -163 | -4.9 | .186 |
| Non-Hispanic Black |
2868 | 3135 (2963 - 3317) | -267 | -8.5 | .002 |
| Non-Hispanic Native Hawaiian |
75 | 75 (43 - 130) | 0 | 0.0 | 1.00 |
| Non-Hispanic White |
1829 | 1954 (1812 - 2108) | -125 | -6.4 | .085 |
| Non-Hispanic Multiple/Unknown |
99 | 55 (32 - 95) | 44 | 80.0 | .080 |
| Age at TB diagnosis in years | |||||
| 0-4 | 401 | 464 (405 - 532) | -63 | -13.6 | .040 |
| 5-14 | 245 | 292 (241 - 352) | -47 | -16.1 | .061 |
| 15-24 | 1274 | 1494 (1360 - 1641) | -220 | -14.7 | <.001 |
| 25-44 | 3893 | 4098 (3897 - 4309) | -205 | -5.0 | .048 |
| 45-64 | 3434 | 3846 (3624 - 4082) | -412 | -10.7 | <.001 |
| 65+ | 2292 | 2358 (2240 - 2482) | -66 | -2.8 | .339 |
| Unknown | 6 | 1 (1 - 1) | 5 | 500.0 | .041 |
| Disease location | |||||
| Pulmonary only | 7976 | 8751 (8436 - 9078) | -775 | -8.9 | <.001 |
| Extrapulmonary only | 2383 | 2594 (2465 - 2730) | -211 | -8.1 | .003 |
| Both | 1028 | 1169 (1031 - 1326) | -141 | -12.1 | .026 |
| Unknown | 158 | 27 (3 - 211) | 131 | 485.2 | .344 |
| Case verification | |||||
| Positive culture | 8876 | 9706 (9423 - 9997) | -830 | -8.6 | <.001 |
| Positive NAA† | 57 | -- | -- | -- | |
| Positive smear | 91 | 63 (45 - 89) | 28 | 44.4 | .084 |
| Clinical case | 1630 | 1426 (1243 - 1637) | 204 | 14.3 | .048 |
| Provider diagnosis | 891 | 1364 (1246 - 1492) | -473 | -34.7 | <.001 |
|
Homeless in the year prior to TB diagnosis |
|||||
| Yes | 571 | 695 (623 - 774) | -124 | -17.8 | <.001 |
| No | 10797 | 11833 (11540 - 12133) | -1036 | -8.8 | <.001 |
| Unknown | 177 | 57 (22 - 147) | 120 | 210.5 | .094 |
| Resident of a correctional facility at time of TB diagnosis | |||||
| Yes | 461 | 480 (389 - 593) | -19 | -4.0 | .682 |
| No | 11041 | 12055 (11796 - 12319) | -1014 | -8.4 | <.001 |
| Unknown | 43 | 7 (2 - 29) | 36 | 514.3 | .189 |
| Excess alcohol use in the year prior to TB diagnosis | |||||
| Yes | 1382 | 1528 (1414 - 1652) | -146 | -9.6 | .013 |
| No | 9877 | 10889 (10641 - 11144) | -1012 | -9.3 | <.001 |
| Unknown | 286 | 180 (129 - 251) | 106 | 58.9 | .016 |
| Injecting drug use in the year prior to TB diagnosis | |||||
| Yes | 152 | 216 (182 - 256) | -64 | -29.6 | <.001 |
| No | 11087 | 12165 (11831 - 12510) | -1078 | -8.9 | <.001 |
| Unknown | 306 | 203 (129 - 320) | 103 | 50.7 | .093 |
| Non-injecting drug use in the year prior to TB diagnosis | |||||
| Yes | 828 | 922 (829 - 1026) | -94 | -10.2 | .046 |
| No | 10391 | 11438 (11178 - 11703) | -1047 | -9.2 | <.001 |
| Unknown | 326 | 221 (137 - 355) | 105 | 47.5 | .122 |
| HIV status at time of TB diagnosis | |||||
| Positive | 706 | 797 (748 - 849) | -91 | -11.4 | .005 |
| Negative | 6337 | 7621 (7171 - 8100) | -1284 | -16.8 | <.001 |
| Unknown | 4502 | 4347 (4134 - 4572) | 155 | 3.6 | .185 |
| Software for TB reporting‡ | |||||
| TIMS | 4455 | 4775 (4552 - 5009) | -320 | -6.7 | .004 |
| Other | 7090 | 7771 (7470 - 8084) | -681 | -8.8 | <.001 |
*Expected case counts are derived from ratios (i.e., regression slopes on log-transformed observed counts). Because the sum of ratios is not the ratio of the sums, expected case counts stratified on case characteristics do not sum to overall case counts. All stratified count differences sum to within the 95% prediction interval (-688 to -1308) for the overall case count difference (-994).
† NAA = nucleic acid amplification test, which was not recorded as a TB case verification criteria until 2009, thus there are no comparable data from which to calculate expected values. In 2009, clinical cases include TB verified by positive interferon gamma release assay (IGRA) in lieu of tuberculin skin test, or by abnormal chest computerized tomography (CT) scan in lieu of chest radiograph; previously, such cases were verified by provider diagnosis because the National Tuberculosis Surveillance System did not collect IGRA or CT scan results prior to 2009.
‡TIMS = Tuberculosis Information Management System in operation since 1998. Other = National Electronic Disease Surveillance System-compliant software newly introduced in 2009.