Rates of VTE by type of endocrine therapy
| . | No. of patients . | Events . | Person-years . | AR . | Univariable Cox model . | Multivariable Cox model† . | |||
|---|---|---|---|---|---|---|---|---|---|
| Rate* . | 95% CI . | HR . | 95% CI . | HR . | 95% CI . | ||||
| Tamoxifen only | 5415 | ||||||||
| Before therapy | 7 | 1 198 | 5.8 | 2.8-12.3 | Ref | Ref | |||
| First 3 months‡ | 30 | 1 246 | 24.1 | 16.8-34.4 | 4.1 | 1.8-9.4 | 5.5 | 2.3-12.7 | |
| Subsequent time | 159 | 30 453 | 5.2 | 4.5-6.1 | 1.1 | 0.5-2.9 | 1.9 | 0.9-4.3 | |
| Aromatase inhibitors only | 1410 | ||||||||
| Before therapy | 28 | 627 | 44.6 | 30.8-64.7 | Ref | Ref | |||
| First 3 months† | 9 | 318 | 28.3 | 14.7-54.3 | 0.6 | 0.3-1.3 | 0.8 | 0.5-1.4 | |
| Subsequent time | 46 | 4 697 | 9.8 | 7.3-13.1 | 0.2 | 0.1-0.4 | 0.3 | 0.2-0.5 | |
| Tamoxifen followed by AIs§ | 3821 | ||||||||
| Before tamoxifen | 18 | 1 121 | 16.1 | 10.1-25.5 | Ref | Ref | |||
| First 3 months of tamoxifen|| | 29 | 859 | 33.8 | 23.5-48.6 | 2.1 | 1.2-3.8 | 2.3 | 1.2-4.4 | |
| Subsequent time for tamoxifen|| | 97 | 8 812 | 11.0 | 9.0-13.4 | 0.7 | 0.4-1.1 | 1.1 | 0.6-2.0 | |
| First 3 months of AIs | 10 | 852 | 11.7 | 6.3-21.8 | 0.7 | 0.3-1.6 | 1.0 | 0.4-2.4 | |
| Subsequent time for AIs¶ | 78 | 11 509 | 6.8 | 5.4-8.5 | 0.4 | 0.2-0.7 | 0.6 | 0.3-1.2 | |
| . | No. of patients . | Events . | Person-years . | AR . | Univariable Cox model . | Multivariable Cox model† . | |||
|---|---|---|---|---|---|---|---|---|---|
| Rate* . | 95% CI . | HR . | 95% CI . | HR . | 95% CI . | ||||
| Tamoxifen only | 5415 | ||||||||
| Before therapy | 7 | 1 198 | 5.8 | 2.8-12.3 | Ref | Ref | |||
| First 3 months‡ | 30 | 1 246 | 24.1 | 16.8-34.4 | 4.1 | 1.8-9.4 | 5.5 | 2.3-12.7 | |
| Subsequent time | 159 | 30 453 | 5.2 | 4.5-6.1 | 1.1 | 0.5-2.9 | 1.9 | 0.9-4.3 | |
| Aromatase inhibitors only | 1410 | ||||||||
| Before therapy | 28 | 627 | 44.6 | 30.8-64.7 | Ref | Ref | |||
| First 3 months† | 9 | 318 | 28.3 | 14.7-54.3 | 0.6 | 0.3-1.3 | 0.8 | 0.5-1.4 | |
| Subsequent time | 46 | 4 697 | 9.8 | 7.3-13.1 | 0.2 | 0.1-0.4 | 0.3 | 0.2-0.5 | |
| Tamoxifen followed by AIs§ | 3821 | ||||||||
| Before tamoxifen | 18 | 1 121 | 16.1 | 10.1-25.5 | Ref | Ref | |||
| First 3 months of tamoxifen|| | 29 | 859 | 33.8 | 23.5-48.6 | 2.1 | 1.2-3.8 | 2.3 | 1.2-4.4 | |
| Subsequent time for tamoxifen|| | 97 | 8 812 | 11.0 | 9.0-13.4 | 0.7 | 0.4-1.1 | 1.1 | 0.6-2.0 | |
| First 3 months of AIs | 10 | 852 | 11.7 | 6.3-21.8 | 0.7 | 0.3-1.6 | 1.0 | 0.4-2.4 | |
| Subsequent time for AIs¶ | 78 | 11 509 | 6.8 | 5.4-8.5 | 0.4 | 0.2-0.7 | 0.6 | 0.3-1.2 | |
Per 1000 person-years.
Adjusted for stage, grade, surgery, chemotherapy, BMI, comorbidity (Charlson score), and age. These variables were fitted by using the same categorization as in multivariable models presented in Table 2.
Three months from day of the first tamoxifen or AI prescription after cancer diagnosis.
An equivalent analysis was not presented for the 233 women (12 VTE events) who switched from AIs to tamoxifen because this number was too small for a meaningful analysis.
Exposure period ceases on the day on which patients switch to AI (if applicable).
Cohort time starting 3 months after initiation of AI therapy until the completion of follow-up.