Table 4.
Multivariable hazards ratio of time to discontinuation during study period among breast cancer patients who initiated adjuvant endocrine therapy, 2007–2009.
| HRa (95% confidence intervals) of discontinuation of AET | |||||
|---|---|---|---|---|---|
|
| |||||
| AJCC Tumor stage I–III | |||||
|
| |||||
| Discontinued AET (%) | Total cohort (n=9,618) | ER+ or PR+ (n=9,110) | ER−/PR− (n=112) | ER/PR unknown (n=396) | |
| Total Cohort | 80.6 | ||||
| Type of AET at initiation | |||||
| Tamoxifen | 80.8 | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) |
| Aromatase Inhibitor | 80.6 | 1.12 (1.05–1.20) | 1.12 (1.05–1.20) | 1.66 (0.91–3.04) | 1.23 (0.87–1.73) |
| AET OOP cost for 30-day supply | |||||
| $0–2.35 | 78.7 | 1 | 1 | 1 | 1 |
| $2.36–6.99 | 81.8 | 1.45 (1.34–1.56) | 1.06 (0.98–1.15) | 1.19 (0.55–2.58) | 0.99 (0.69–1.42) |
| $7.00–34.99 | 85.6 | 1.53 (1.41–1.65) | 1.43 (1.32–1.54) | 3.69 (1.69–8.00) | 1.40 (0.93–2.11) |
| $35.00–93.50 | 81.5 | 0.95 (0.87–1.03) | 1.53 (1.41–1.66) | 0.86 (0.33–2.21) | 1.38 (0.86–2.07) |
| >$93.50 | 75.9 | 1.12 (1.05–1.20) | 0.94 (0.87–1.02) | 0.91 (0.37–2.25) | 0.88 (0.56–1.40) |
| Race/Ethnicity | |||||
| Non-Hispanic white | 80.8 | 1 | 1 | 1 | 1 |
| Non-Hispanic Black | 76.7 | 0.91 (0.83–1.01) | 0.89 (0.80–0.98) | 0.72 (0.30–1.72) | 1.43 (0.91–2.23) |
| Hispanic | 82.7 | 1.01 (0.92–1.12) | 1.02 (0.92–1.13) | 1.10 (0.45–2.72) | 0.93 (0.59–1.46) |
| Asian | 80.6 | 0.83 (0.74–0.92) | 0.83 (0.72–0.93) | 0.29 (0.08–1.02) | 0.97 (0.52–1.81) |
| Age (years) | |||||
| 65–69 | 81.6 | 1 | 1 | 1 | 1 |
| 70–74 | 82.5 | 1.03 (0.97–1.10) | 1.04 (0.97–1.10) | 0.94 (0.45–1.96) | 1.08 (0.76–1.55) |
| 75–79 | 81.4 | 1.02 (0.96–1.09) | 1.03 (0.96–1.10) | 1.86 (0.83–4.15) | 0.85 (0.59–1.22) |
| ≥80 | 76.9 | 1.04 (0.97–1.12) | 1.04 (0.97–1.12) | 1.70 (0.70–4.13) | 1.18 (0.81–1.71) |
| SES (% living below FPL) | |||||
| 1st tertile (<5.4) | 79.9 | 1 | 1 | 1 | 1 |
| 2nd tertile (5.4–11.8) | 81.9 | 1.01 (0.96–1.07) | 1.02 (0.96–1.08) | 0.91 (0.45–1.82) | 0.74 (0.50–1.09) |
| 3rd tertile (>11.8) | 80.1 | 1.02 (0.96–1.09) | 1.02 (0.96–1.10) | 1.83 (0.82–4.08) | 0.79 (0.53–1.18) |
| Comorbidity scores | 81.3 | ||||
| 0 | 81.3 | 1 | 1 | 1 | 1 |
| 1 | 81.5 | 1.04 (0.99–1.10) | 1.05 (1.00–1.11) | 0.66 (0.35–1.27) | 0.86 (0.63–1.17) |
| 2 | 78.9 | 1.07 (0.99–1.61) | 1.08 (1.00–1.18) | 0.93 (0.41–2.12) | 0.99 (0.68–1.45) |
| 3+ | 74.9 | 1.07 (0.97–1.17) | 1.05 (0.95–1.15) | 1.22 (0.51–2.93) | 1.29 (0.78–2.13) |
HR, hazards ratio; AET, adjuvant endocrine therapy; ER, estrogen receptor; PR, progesterone receptor; OOP, out-of-pocket cost.
a
HR controlled for marital status, metropolitan area, tumor size, node status, tumor grade, tumor stage, surgical treatment, and chemotherapy and radiation treatment.