Table 4.
Modified Poisson Regression Results for the Association Between Race and Covariates and ODX Testing in Patients With Node-Positive Breast Cancer
| Characteristic | Primary Model | Secondary Model | ||||
|---|---|---|---|---|---|---|
| RR | 95% CI | P | RR | 95% CI | P | |
| Black v non-black* | 0.54 | 0.35 to 0.84 | .006 | 0.68 | 0.39 to 1.19 | .17 |
| Tumor size v < 2 cm, cm | ||||||
| 2-5 | 0.82 | 0.54 to 1.24 | .35 | 0.90 | 0.59 to 1.39 | .64 |
| > 5 | 0.86 | 0.13 to 5.57 | .88 | 1.30 | 0.20 to 8.26 | .79 |
| Grade v 1 | ||||||
| 2 | 1.19 | 0.77 to 1.83 | .44 | 1.24 | 0.76 to 2.04 | .39 |
| 3 | 0.57 | 0.26 to 1.24 | .16 | 0.56 | 0.27 to 1.16 | .12 |
| PR positive v negative | 1.02 | 0.60 to 1.75 | .94 | 1.08 | 0.58 to 2.03 | .80 |
| Mastectomy v lumpectomy | 0.84 | 0.56 to 1.27 | .41 | 0.93 | 0.62 to 1.39 | .71 |
| No. of comorbidities | 0.87 | 0.68 to 1.11 | .25 | 0.88 | 0.71 to 1.08 | .23 |
| Age at diagnosis < 50 v > 50 years | 0.49 | 0.32 to 0.75 | .001 | 0.52 | 0.33 to 0.80 | .003 |
| Diagnosis year v 2008 | ||||||
| 2009 | 2.40 | 0.85 to 6.75 | .097 | 1.99 | 0.71 to 5.55 | .19 |
| 2010 | 2.061 | 0.81 to 5.26 | .13 | 1.65 | 0.60 to 4.53 | .33 |
| 2011 | 2.53 | 0.97 to 6.56 | .057 | 2.00 | 0.80 to 5.015 | .14 |
| 2012 or 2013 | 3.17 | 1.15 to 8.76 | .026 | 3.10 | 1.088 to 8.86 | .034 |
| Family income v < $15,000, $ | ||||||
| 15,000-30,000 | 1.497 (0.790) | .446 | ||||
| 30,000-50,000 | 0.952 (0.558) | .934 | ||||
| > 50,000 | 2.516 (1.350) | .087 | ||||
| Not reported | 0.802 (0.791) | .791 | ||||
| Uninsured v insured | 0.73 | 0.24 to 2.25 | .58 | |||
| Married v unmarried | 0.93 | 0.59 to 1.48 | .77 | |||
| Employment v unemployed | ||||||
| Employed | 0.82 | 0.53 to 1.25 | .35 | |||
| Not reported | 3.53 | 1.37 to 9.10 | .009 | |||
| Education v HS or v HS or higher | ||||||
| College or higher | 0.62 | 0.40 to 0.96 | .031 | |||
| Less than HS | 0.74 | 0.27 to 2.033 | .56 | |||
| Constant† | 0.22 | 0.071 to 0.71 | .011 | 0.16 | 0.032 to 0.83 | .029 |
NOTE. N = 360. The number of primary sampling units (ie, provider) used to account for provider-level clustering was 232. Population-weighted sample size = 1,047. Primary model covariates were tumor size, tumor grade, progesterone receptor status, surgery type, number of comorbidities, age at diagnosis, and year of diagnosis. Additional secondary model covariates were family income, health insurance status, marital status, employment status, and education level.
Abbreviations: HS, high school; ODX, Oncotype DX (Genomic Health, Redwood City, CA); PR, progesterone receptor; RR, risk ratio.
Results for the crude model were RR, 0.42; 95% CI, 0.27 to 0.66; P = < .001.
Results for the crude model were RR, 0.34; 95% CI, 0.27 to 0.43; P = < .001.