Table 3.
Hazard ratio (HR), 95% confidence intervals (CI), and details of the statistical analysis for the association between at/around diagnosis smoking status (cessation/continuation) and bladder cancer overall and bladder cancer-specific survival.
| Author, Year | Patients Group (According to Smoking Status) | HR | 95% CI | Variables Used for Statistical Adjustment | Exclusion of Events within Predetermined Time from the Start of Follow-Up |
|---|---|---|---|---|---|
| Overall survival | |||||
| Koshiaris, 2017 [26] | continued smokers | 1.00 (ref.) | Age, sex, treatment, other | Yes (deaths within the first annual follow-up after diagnosis) | |
| Quitters | 1.02 | 0.81–1.30 | |||
| Tao, 2013 [28] (a),(b) | Smoking cessation (time-varying) | 0.34 | 0.13–0.92 | Age, cumulative smoking, treatment, other | Yes (deaths within the first annual follow-up after diagnosis) |
| Sfakianos, 2010 [30] | Never smokers | 1.00 (ref.) | Age, sex, tumour stage | No or not mentioned | |
| Continued smokers | 1.03 | 0.63–1.68 | |||
| Quitters | 0.64 | 0.31–1.34 | |||
| Bladder cancer-specific survival | |||||
| Koshiaris, 2017 [26] | Continued smokers | 1.00 (ref.) | Age, sex, treatment, other | Yes (deaths within the first annual follow-up after diagnosis) | |
| Quitters | 1.25 | 0.71–2.20 | |||
| Lee, 2012 [29] | Never smokers | 1.00 (ref.) | Age, tumour stage and grade, other | No or not mentioned | |
| Continued smokers | 1.17 | 0.64–2.13 | |||
| Quitters | 1.17 | 0.78–1.75 | |||
| Sfakianos, 2010 [30] | Never smokers | 1.00 (ref.) | Age, sex, tumour stage | No or not mentioned | |
| Continued smokers | 1.27 | 0.64–2.52 | |||
| Quitters | 0.80 | 0.30–2.18 | |||
(a) The HR and corresponding 95% CI were inverted to make continued smokers the reference category. (b) The HR comparing those who had never smoked after diagnosis (quitters) and those who had never stopped after diagnosis (continued smokers) was 0.06 (95% CI 0.01–0.44). HR: hazard ratio. CI: confidence intervals.