Table 2.
Incidence rate and HR of bladder cancer with pioglitazone use: the KPNC diabetes registry, 1997–2008
| Median (range) bladder cancer incidence rate (per 100,000 person-years) | HR (95% CI) adjusted for age and sex | Fully adjusted HR (95% CI)* | |
|---|---|---|---|
| Never use of pioglitazone | 68.8 (64.1–73.6) | Ref. | Ref. |
| Ever use of pioglitazone† | 81.5 (64.7–98.4) | 1.2 (0.9–1.5)‡ | 1.2 (0.9–1.5) |
| Time since starting pioglitazone (months)† | |||
| <18 | 67.1 (41.8–92.4) | 1.1 (0.8–1.6) | 1.2 (0.8–1.7) |
| 18–36 | 85.2 (51.8–118.6) | 1.3 (0.9–2.0) | 1.4 (0.9–2.1) |
| >36 | 93.1 (63.5–122.7) | 1.3 (0.9–1.8) | 1.3 (0.9–1.8) |
| Ptrend | — | 0.04 | 0.07 |
| Duration of therapy (months)† | |||
| <12 | 48.4 (29.0–67.8) | 0.8 (0.5–1.2) | 0.8 (0.6–1.3) |
| 12–24 | 86.7 (52.0–121.4) | 1.3 (0.9–2.0) | 1.4 (0.9–2.1) |
| >24 | 102.8 (71.7–133.8) | 1.5 (1.1–2.0) | 1.4 (1.03–2.0) |
| Ptrend | — | 0.02 | 0.03 |
| Cumulative dose (mg)† | |||
| 1–10,500 | 59.7 (39.0–80.4) | 1.0 (0.7–1.4) | 1.0 (0.7–1.5) |
| 10,501–28,000 | 76.8 (48.3–105.2) | 1.1 (0.8–1.6) | 1.2 (0.8–1.8) |
| >2,8000 | 105.9 (68.0–143.8) | 1.5 (1.1–2.2) | 1.4 (0.96–2.1) |
| Ptrend | — | 0.05 | 0.08 |
*Includes all potential confounders listed in Table 1 in the statistical model.
†Never use of pioglitazone was the reference group for the calculation of the HR associated with ever use of pioglitazone and time, duration, and dose of pioglitazone use.
‡Also adjusted for use of other diabetes medications.