Table 2.
Multivariable Logistic Regression Analysis for Completion of Trastuzumab Treatment in > 270 Days
| Variable | OR | 95% CI | P* |
|---|---|---|---|
| Age at diagnosis, years | < .001 | ||
| 66-70 | 1.00 | ||
| 71-75 | 0.79 | 0.60 to 1.04 | |
| 76-80 | 0.57 | 0.35 to 0.91 | |
| ≥ 80 | 0.40 | 0.30 to 0.55 | |
| Race/ethnicity | .002 | ||
| Non-Hispanic white | 1.00 | ||
| Non-Hispanic black | 0.83 | 0.64 to 1.08 | |
| Hispanic/other/unknown | 0.56 | 0.40 to 0.78 | |
| SEER region† | < .001 | ||
| California/Hawaii | 1.00 | ||
| Detroit | 1.26 | 1.06 to 1.49 | |
| New Mexico | 1.85 | 1.55 to 2.21 | |
| Atlanta/Rural Georgia | 1.11 | 1.00 to 1.23 | |
| Kentucky/Connecticut/Iowa/Seattle/Utah | 1.13 | 0.90 to 1.43 | |
| Louisiana | 1.29 | 1.14 to 1.47 | |
| New Jersey | 0.99 | 0.93 to 1.06 | |
| Location of residence | .40 | ||
| Major metropolitan | 1.00 | ||
| Metropolitan/urban | 0.91 | 0.70 to 1.20 | |
| Less urban/rural | 1.12 | 0.81 to 1.54 | |
| Socioeconomic status, median income (quartile) | .02 | ||
| 1 (lowest) | 1.00 | ||
| 2 | 0.78 | 0.65 to 0.95 | |
| 3 | 0.94 | 0.68 to 1.30 | |
| 4 (highest) | 1.14 | 0.86 to 1.53 | |
| High school graduation rates (quartile) | .14 | ||
| 1 (lowest) | 1.00 | ||
| 2 | 1.42 | 1.05 to 1.94 | |
| 3 | 1.35 | 1.02 to 1.79 | |
| 4 (highest) | 1.29 | 0.83 to 2.00 | |
| Marital status | .40 | ||
| Single‡ | 1.00 | ||
| Married | 0.90 | 0.71 to 1.14 | |
| Charlson comorbidity score | .02 | ||
| 0 | 1.00 | ||
| 1 | 0.82 | 0.70 to 0.96 | |
| ≥ 2 | 0.65 | 0.49 to 0.88 | |
| Year of initiation of trastuzumab | .006 | ||
| 2009 | 1.00 | ||
| 2008 | 1.26 | 1.00 to 1.58 | |
| 2007 | 0.89 | 0.66 to 1.21 | |
| 2006 | 0.96 | 0.68 to 1.35 | |
| 2005 | 0.87 | 0.44 to 1.69 | |
| Tumor size, cm | .45 | ||
| 0-2 | 1.00 | ||
| 2.1-3 | 1.10 | 0.90 to 1.35 | |
| > 3 | 1.15 | 0.86 to 1.54 | |
| Unknown | 1.49 | 0.82 to 2.69 | |
| No. of positive nodes | .27 | ||
| 0 | 1.00 | ||
| 1-3 | 0.86 | 0.64 to 1.15 | |
| 4-9 | 0.98 | 0.68 to 1.43 | |
| ≥ 100 | 0.84 | 0.52 to 1.35 | |
| Unknown | 0.73 | 0.47 to 1.14 | |
| Tumor grade | .67 | ||
| High | 1.00 | ||
| Low/intermediate | 1.05 | 0.83 to 1.33 | |
| Hormone receptor status§ | .53 | ||
| Positive | 1.00 | ||
| Negative | 0.97 | 0.87 to 1.07 | |
| Surgery | .05 | ||
| Mastectomy | 1.00 | ||
| Lumpectomy | 1.24 | 1.00 to 1.54 | |
| Chemotherapy | < .001 | ||
| Anthacycline-taxane‖ | 1.00 | ||
| Anthracycline based¶ | 1.57 | 1.04 to 2.37 | |
| Taxane-based multidrug regimen# | 1.98 | 1.66 to 2.37 | |
| Taxane only | 1.06 | 0.76 to 1.49 | |
| Other chemotherapy | 0.97 | 0.60 to 1.55 | |
| No chemotherapy | 1.28 | 0.97 to 1.68 |
NOTE. Multivariable logistic regression was used, accounting for clustering at registry level and adjusting for all variables in the table.
Abbreviation: SEER, Surveillance, Epidemiology, and End Results.
P calculated by Wald test.
Regions collapsed because of small sample sizes.
Single, separated, widowed, and divorced categories were collapsed.
Defined as positive if estrogen receptor–positive or progesterone receptor–positive. Defined as negative if estrogen receptor–negative or progesterone receptor–negative, and neither were positive. Patients with unknown hormone receptor status were considered hormone receptor positive.
The majority of patients received doxorubicin, cyclophosphamide, and paclitaxel.
The majority of patients received doxorubicin and cyclophosphamide.
The majority of patients received docetaxel and carboplatin.