Table 1.
Cohort characteristics stratified by outcome (airway disease or censored) among people immigrating to British Columbia, Canada, 1985–2015.
| Characteristic | Censored N (%) | Airway disease N (%) | Crude HR | 95% CI |
|---|---|---|---|---|
| Total | 888 488 | 116 840 | ||
| Respiratory tuberculosis | 656 (0·07) | 485 (0·42) | 3·24* | 2·96–3·54 |
| Follow-up time (mean (SD)) | 11·56 (7·36) | 7·97 (6·02) | ||
| Sex | ||||
| Female | 455 737 (51·29) | 62 248 (53·28) | Ref | Ref |
| Male | 432 751 (48·71) | 54 592 (46·72) | 0·95* | 0·94–0·96 |
| Age, years (mean (SD)) | 32·41 (16·33) | 35·04 (18·81) | 1·01* | 1·01–1·01 |
| Neighbourhood income quintile | ||||
| Highest 20% | 133 301 (15·00) | 13 468 (11·53) | Ref | Ref |
| Middle-High 20% | 128 939 (14·51) | 15 001 (12·84) | 1·14* | 1·12–1·17 |
| Middle 20% | 161 746 (18·20) | 21 343 (18·27) | 1·28* | 1·25–1·31 |
| Low-Middle 20% | 201 033 (22·63) | 29 692 (25·41) | 1·40* | 1·37–1·43 |
| Lowest 20% | 263 469 (29·65) | 37 336 (31·95) | 1·37* | 1·35–1·40 |
| Education level | ||||
| None/Unknown | 109 282 (12·30) | 18 657 (15·97) | Ref | Ref |
| Secondary or less | 374 619 (42·16) | 57 554 (49·26) | 0·76* | 0·74–0·77 |
| Trade/diploma | 164 367 (18·50) | 20 595 (17·63) | 0·65* | 0·64–0·66 |
| University degree | 240 220 (27·04) | 20 034 (17·15) | 0·54* | 0·53–0·55 |
| Immigration class | ||||
| Economic | 544 098 (61·24) | 50 362 (43·10) | Ref | Ref |
| Family | 253 158 (28·49) | 50 522 (43·24) | 1·86* | 1·84–1·88 |
| Refugee | 23 900 (2·69) | 3957 (3·39) | 1·52* | 1·49–1·55 |
| Other | 67 332 (7·58) | 11 999 (10·27) | 1·49* | 1·44–1·54 |
| TB incidence rate in country of origin at time of immigration | ||||
| <100 per 100 000 pop· | 381 530 (42·94) | 36 967 (31·64) | Ref | Ref |
| 100 to <200 per 100 000 pop· | 292 116 (32·88) | 35 552 (30·43) | 1·02* | 1·00–1·03 |
| 200 to <300 per 100 000 pop· | 112 878 (12·70) | 30 077 (25·74) | 2·01* | 1·98–2·04 |
| 300+ per 100 000 pop· | 101 964 (11·48) | 14 244 (12·19) | 1·23* | 1·20–1·25 |
| Year of immigration (mean (SD)) | 15·16 (7·01) | 10·21 (6·16) | 0·96* | 0·96–0·96 |
| Charlson comorbidity score (mean (SD)) | 0·05 (0·33) | 0.09 (0·37) | 1·38* | 1·37–1·39 |
| Ethanol dependence | ||||
| No | 888 331 (99·98) | 116 442 (99·70) | Ref | Ref |
| Yes | 157 (0·018) | 398 (0·30) | 2·02* | 1·83–2·23 |
| Substance dependence | ||||
| No | 888 359 | 116 440 (99·70) | Ref | Ref |
| Yes | 129 (0·015) | 400 (0·30) | 1·75* | 1·59–1·93 |
| Psychosis | ||||
| No | 888 314 (99·98) | 116 366 (99·60) | Ref | Ref |
| Yes | 174 (0·02) | 474 (0·40) | 1·53* | 1·40–1·68 |
| Depression | ||||
| No | 883 806 (99·47) | 107 651 (92·10) | Ref | Ref |
| Yes | 4682 (0·53) | 9189 (7·90) | 1·78* | 1·75–1·82 |
| Personal health risk proxy variable | ||||
| No | 826 181 (92·99) | 101 531 (86·90) | Ref | Ref |
| Yes | 62 307 (7·01) | 15 309 (13·10) | 1·83* | 1·80–1·86 |
Legend: CI = confidence interval; ETOH = ethanol dependence; HR =hazard ratio; Ref = reference category for HR; asterisk (*) indicates result was significant at α=0·05. Notes: The censored group includes all people who did not experience the event (airway disease) prior to or at the time of death, leaving BC, or study end date (December 31, 2015). Univariable Cox proportional hazards regressions estimated hazard ratios for airway disease by each covariate.