Table 1.
Cohort characteristics among migrants to British Columbia, Canada, 1985–2015: comparison of people who died of non-TB causes (event) with those censored
| Event n (%) | Censored n (%) | Crude HRa | pa | |
|---|---|---|---|---|
| Total cohort (N) | 24,887 | 1,005,986 | ||
| Tuberculosis patients | 285 (1.1) | 2150 (0.2) | 3.06 | < 0.01 |
| Male | 13,389 (53.8) | 487,144 (48.4) | 1.28 | < 0.01 |
| Age at index in years (mean (SD)) | 57.92 (17.51) | 30.11 (16.14) | 1.10 | < 0.01 |
| Charlson Comorbidity Index (mean (SD))b | 0.81 (1.67) | 0.13 (0.50) | 1.52 | < 0.01 |
| Neighbourhood income quintile | < 0.01 | |||
| Highest 20% | 3413 (13.7) | 146,827 (14.6) | 1 (ref) | |
| Middle-high 20% | 3624 (14.6) | 144,031 (14.3) | 1.07 | |
| Middle 20% | 4534 (18.2) | 183,237 (18.2) | 1.04 | |
| Low-middle 20% | 6219 (25.0) | 230,383 (22.9) | 1.09 | |
| Lowest 20% | 7097 (28.5) | 301,508 (30.0) | 0.99 | |
| Educational qualification | < 0.01 | |||
| None/unknown | 3532 (14.2) | 129,308 (12.9) | 1 (ref) | |
| Secondary or less | 13,756 (55.3) | 427,478 (42.5) | 0.95 | |
| Trade/diploma | 4318 (17.4) | 184,562 (18.3) | 0.74 | |
| University degree | 3281 (13.2) | 264,638 (26.3) | 0.57 | |
| Immigration class | < 0.01 | |||
| Economic | 4897 (19.7) | 605,414 (60.2) | 1 (ref) | |
| Family | 16,072 (64.6) | 295,100 (29.3) | 5.27 | |
| Refugee | 1499 (6.0) | 79,550 (7.9) | 1.59 | |
| Other | 2419 (9.7) | 25,922 (2.6) | 8.18 | |
| TB incidence in country of birth | < 0.01 | |||
| < 100 per 100,000 population | 8699 (35.0) | 422,089 (42.0) | 1 (ref) | |
| 100 to < 200 per 100,000 population | 8815 (35.4) | 325,569 (32.4) | 0.99 | |
| 200 to < 300 per 100,000 population | 5322 (21.4) | 141,871 (14.1) | 1.22 | |
| 300+ per 100,000 population | 2051 (8.2) | 116,457 (11.6) | 0.69 | |
| Index year (mean (SD))c | 8.58 (5.88) | 14.85 (7.12) | 0.97 | < 0.01 |
HR, crude hazard ratio; p, p value; SD, standard deviation; TB, tuberculosis
aCalculated from univariable Cox proportional hazards regressions for association between time-to-non-TB mortality and each cohort characteristic. bWeighted Charlson comorbidity score calculated in the year prior to TB diagnosis or randomly selected reference date for non-TB controls using both physician claims data and hospital discharge abstracts data (all diagnosis fields).cIndex year is calculated as 0 = 1985 to 30 = 2015 (continuous) and represents the year residency in BC was established