Table 2.
Multivariable Logistic Regression Analyses With Multiple Imputation
| Variable | RS-Eligible Patients (n = 2,418) | RS-Receipt Patients (n = 377) | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Received RS | Chemotherapy | Chemotherapy | |||||||
| OR | 95% CI | P | OR | 95% CI | P | OR | 95% CI | P | |
| Health care system | .02 | .38 | .11 | ||||||
| University | Ref | Ref | Ref | Ref | Ref | Ref | |||
| Community | 1.14 | 0.86 to 1.51 | .36 | 0.86 | 0.66 to 1.11 | .26 | 1.19 | 0.59 to 2.42 | .62 |
| Dual | 1.73 | 1.18 to 2.55 | .01 | 1.05 | 0.71 to 1.54 | .82 | 2.47 | 1.01 to 6.04 | .05 |
| RS receipt | .11 | ||||||||
| Not received | — | — | Ref | Ref | — | — | |||
| Received | 0.78 | 0.58 to 1.05 | .11 | ||||||
| RS | < .001 | ||||||||
| Low | Ref | Ref | |||||||
| Intermediate | — | — | — | — | 3.66 | 1.94 to 6.91 | < .001 | ||
| High | 49.39 | 14.06 to 173.46 | < .001 | ||||||
| Age at diagnosis, years | < .001 | < .001 | < .001 | ||||||
| < 40 | 0.42 | 0.23 to 0.74 | .0031 | 4.69 | 2.89 to 7.62 | < .001 | 13.01 | 2.78 to 60.77 | .001 |
| 40-49 | 1.13 | 0.85 to 1.49 | .41 | 2.83 | 2.14 to 3.73 | < .001 | 5.70 | 2.87 to 11.30 | < .001 |
| 50-64 | Ref | Ref | Ref | Ref | Ref | Ref | |||
| ≥ 65 | 0.27 | 0.17 to 0.43 | < .001 | 0.19 | 0.13 to 0.29 | < .001 | 0.18 | 0.03 to 1.08 | .06 |
| Year of diagnosis | < .001 | .12 | .03 | ||||||
| 2005-2007 | Ref | Ref | Ref | Ref | Ref | Ref | |||
| 2008-2009 | 2.76 | 2.00 to 3.82 | < .001 | 0.80 | 0.60 to 1.06 | .12 | 2.10 | 0.89 to 4.98 | .09 |
| 2010-2011 | 3.68 | 2.72 to 4.98 | < .001 | 0.77 | 0.59 to 1.00 | .05 | 0.86 | 0.38 to 1.95 | .71 |
| Race | .62 | .03 | .5 | ||||||
| Non-Hispanic white | Ref | Ref | Ref | Ref | Ref | Ref | |||
| Hispanic | 0.94 | 0.55 to 1.62 | .83 | 1.30 | 0.79 to 2.13 | .3 | 0.63 | 0.15 to 2.61 | .52 |
| Non-Hispanic black | 0.44 | 0.12 1.53 | .19 | 3.08 | 1.26 to 7.55 | .01 | 1.90 | 0.11 to 32.21 | .66 |
| Non-Hispanic Asian/Pacific Islander | 0.96 | 0.70 to 1.31 | .79 | 1.29 | 0.96 to 1.72 | .09 | 0.60 | 0.28 to 1.27 | .18 |
| Neighborhood SES statewide quintile | .51 | .41 | .57 | ||||||
| 1 | Ref | Ref | Ref | Ref | Ref | Ref | |||
| 2 | 0.81 | 0.32 to 2.04 | .65 | 1.79 | 0.72 to 4.47 | .21 | 1.76 | 0.17 to 18.00 | .63 |
| 3 | 0.72 | 0.32 to 1.64 | .43 | 1.12 | 0.49 to 2.57 | .79 | 0.87 | 0.11 to 7.04 | .89 |
| 4 | 0.67 | 0.30 to 1.47 | .31 | 1.30 | 0.58 to 2.95 | .52 | 2.24 | 0.30 to 16.92 | .43 |
| 5 | 0.87 | 0.40 to 1.89 | .73 | 1.11 | 0.51 to 2.44 | .79 | 1.24 | 0.19 to 8.06 | .82 |
| Insurance | .4 | .19 | .17 | ||||||
| Private | Ref | Ref | Ref | Ref | Ref | Ref | |||
| Medicare | 0.85 | 0.51 to 1.40 | .51 | 0.67 | 0.44 to 1.03 | .07 | 3.30 | 0.49 to 22.26 | .22 |
| Other | 0.66 | 0.34 to 1.27 | .21 | 0.87 | 0.51 to 1.48 | .6 | 3.22 | 0.71 to 14.56 | .13 |
| Stage | .42 | < .001 | .01 | ||||||
| I | Ref | Ref | Ref | Ref | Ref | Ref | |||
| II | 0.88 | 0.66 to 1.19 | .42 | 3.62 | 2.73 to 4.79 | < .001 | 2.74 | 1.34 to 5.62 | .01 |
| No. of involved lymph nodes | < .001 | < .001 | .21 | ||||||
| 0 | Ref | Ref | Ref | Ref | Ref | Ref | |||
| 1-2 | 0.19 | 0.12 to 0.29 | < .001 | 4.32 | 3.12 to 5.97 | < .001 | 1.96 | 0.68 to 5.61 | .21 |
| Grade | .007 | < .001 | .01 | ||||||
| 1 | Ref | Ref | Ref | Ref | Ref | Ref | |||
| 2 | 1.21 | 0.92 to 1.59 | .17 | 3.12 | 2.37 to 4.11 | < .001 | 2.70 | 1.33 to 5.51 | .01 |
| 3 | 0.67 | 0.44 to 1.01 | .06 | 10.85 | 7.44 to 15.82 | < .001 | 4.53 | 1.58 to 12.94 | .005 |
| Histology | .22 | .06 | .02 | ||||||
| Ductal | Ref | Ref | Ref | Ref | Ref | Ref | |||
| Lobular | 1.39 | 0.96 to 2.02 | .08 | 0.75 | 0.51 to 1.11 | .15 | 0.34 | 0.11 to 0.98 | .05 |
| Other | 1.06 | 0.75 to 1.52 | .73 | 0.69 | 0.49 to 0.98 | .04 | 0.35 | 0.13 to 0.90 | .03 |
| Laterality | .79 | .52 | |||||||
| Unilateral | Ref | Ref | Ref | Ref | —* | ||||
| Bilateral | 1.09 | 0.56 to 2.13 | .79 | 0.81 | 0.42 to 1.55 | .52 | |||
NOTE. Logistic regression models were fit to multiply-imputed data by using five imputations. Coefficient P values and variable P values (in bold) were calculated by using Wald’s z test.
Abbreviations: OR, odds ratio; Ref, reference; RS, recurrence score; SES, socioeconomic status.
*
Categories were collapsed because there were few observations.