Table 3 Hazard ratios (HR, 95% confidence interval) of lung cancer mortality for the major groups of smoking cessation reassessed during the follow-up period (1981–2014) according to subgroups categorised by types of occupation, radiological severity of silicosis at diagnosis, and history of tuberculosis
Major smoking groups | ||||
|---|---|---|---|---|
Characters of exposure | Never smokers | Persistent quitters | New quitters | Never quitters |
Entire cohorta | 0.11(0.04–0.31) [4] | 0.47(0.33–0.66) [61] | 0.51(0.34–0.76) [35] | 1.00 [87] |
Surface construction | 0.09(0.02–0.36) [2] | 0.41(0.26–0.64) [33] | 0.42(0.24–0.74) [15] | 1.00 [53] |
Underground caisson | 0.28(0.06–1.24) [2] | 0.67(0.37–1.22) [22] | 0.73(0.39–1.37) [17] | 1.00 [23] |
Radiological severity of silicosisa | ||||
Small opacities | 0.10(0.03–0.32) [3] | 0.38(0.26-0.57) [41] | 0.52(0.35–0.78) [33] | 1.00 [77] |
Large opacities | 0.20(0.02–1.67) [1] | 1.08(0.49-2.38) [20] | 0.31(0.07–1.43) [2] | 1.00 [10] |
History of tuberculosisb | ||||
No | 0.08(0.02–0.32) [2] | 0.50(0.32–0.78) [34] | 0.59(0.36–0.95) [25] | 1.00 [53] |
Yes | 0.16(0.04–0.70) [2] | 0.42(0.25–0.69) [27] | 0.39(0.19–0.80) [10] | 1.00 [34] |
