Table 2.
Multivariable Cox proportional hazards model, propensity score-adjustment, and IPTW analyses of the effect of co-administration of PPIs on relapse-free survival of the entire population (capecitabine monotherapy and CapeOX regimen).
| Multivariable analysis | Adjusted for propensity score | IPTW | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Variables | No. | Event | Censored | HR (95% CI) | P-value | Posterior probability | HR (95% CI) | P-value | Posterior probability | HR (95% CI) | P-value | Posterior probability | |
| PPI | Yes | 54 | 15 | 39 | 1.43 (0.81–2.51) | 0.215 | 0.135 | 1.37 (0.79–2.41) | 0.265 | 0.159 | 1.54 (0.85–2.80) | 0.158 | 0.077 |
| No | 552 | 110 | 442 | 1 | 1 | 1 | |||||||
| Age (10-year intervals) | – | – | – | 0.89 (0.75–1.05) | 0.178 | ||||||||
| Sex | Male | 328 | 76 | 252 | 1.40 (0.97–2.01) | 0.072 | |||||||
| Female | 278 | 49 | 229 | 1 | |||||||||
| Primary site | Right-sided colon | 171 | 39 | 132 | 1.13 (0.77–1.67) | 0.536 | |||||||
| Others | 435 | 86 | 349 | 1 | |||||||||
| Stage | III high-risk | 199 | 67 | 132 | 2.33 (1.26–4.30) | 0.007 | |||||||
| III low-risk | 334 | 45 | 289 | 0.78 (0.42–1.46) | 0.443 | ||||||||
| II | 73 | 13 | 60 | 1 | |||||||||
| Regimen | CapeOX | 157 | 39 | 118 | 0.90 (0.59–1.38) | 0.639 | |||||||
| Capecitabine | 449 | 86 | 363 | 1 | |||||||||
| RDI (10% intervals) | – | – | – | 0.93 (0.86–1.01) | 0.088 | ||||||||
Abbreviations: CapeOX, capecitabine and oxaliplatin; CI, confidence interval; HR, hazard ratio; IPTW, inverse probability of treatment weighting; PPI, proton pump inhibitor; RDI, relative dose intensity.