Table 3. Sitagliptin exposure and hazard ratios for thyroid cancer.
| Sitagliptin use/subgroups of metformin use | All patients | Excluding patients with benign thyroid disease | ||||
|---|---|---|---|---|---|---|
| HR | 95% CI | P | HR | 95% CI | P | |
| I. Original sample | ||||||
| Ever users | 1.516 | (1.011-2.271) | 0.0439 | 1.623 | (0.978-2.694) | 0.0612 |
| Tertiles of cumulative duration of sitagliptin therapy (months) | ||||||
| <6.53 | 1.995 | (1.015-3.919) | 0.0451 | 2.582 | (1.193-5.591) | 0.0161 |
| 6.53-14.00 | 2.516 | (1.451-4.364) | 0.0010 | 2.358 | (1.141-4.872) | 0.0205 |
| >14 | 0.595 | (0.244-1.449) | 0.2530 | 0.590 | (0.187-1.862) | 0.3681 |
| Subgroups of metformin use | ||||||
| Metformin non-users | 1.058 | (0.418-2.680) | 0.9045 | 1.105 | (0.333-3.663) | 0.8709 |
| Metformin users | 1.675 | (1.067-2.630) | 0.0251 | 1.792 | (1.021-3.145) | 0.0420 |
| II. Matched sample | ||||||
| Ever users | 1.462 | (0.866-2.466) | 0.1551 | 1.597 | (0.829-3.077) | 0.1617 |
| Tertiles of cumulative duration of sitagliptin therapy (months) | ||||||
| <6.53 | 1.936 | (0.906-4.137) | 0.0881 | 2.725 | (1.126-6.595) | 0.0262 |
| 6.53-14.00 | 2.301 | (1.208-4.386) | 0.0113 | 2.261 | (0.978-5.225) | 0.0563 |
| >14 | 0.574 | (0.222-1.483) | 0.2516 | 0.557 | (0.164-1.886) | 0.3469 |
| Subgroups of metformin use | ||||||
| Metformin non-users | 0.912 | (0.288-2.882) | 0.8747 | 1.005 | (0.224-4.512) | 0.9949 |
| Metformin users | 1.662 | (0.923-2.993) | 0.0907 | 1.789 | (0.863-3.710) | 0.1178 |
Cox regression models were created by incorporation with the inverse probability of treatment weighting using propensity score created from variables in Table 1.
Referent group: never users of sitagliptin
HR: hazard ratio, CI: confidence intervals