Table 3 Multivariable model of variables associated with discontinuation of endocrine therapy among women who were eligible for Oncotype Dx testing (N = 3949)

Tested

0.10

 Yes

0.93

(0.85–1.02)

 No (ref)

Year diagnosed

<0.001

 2006–2007 (ref)

 2008–2009

1.62

(1.48–1.78)

 2010

2.71

(2.37–3.11)

Age at diagnosis, years

0.002

 24–39 (ref)

 40–49

0.75

(0.65–0.88)

 50–59

0.74

(0.63–0.88)

 60–63

0.80

(0.66–0.97)

Race-ethnicity

0.03

 NH white (ref)

 NH black

1.32

(1.08–1.61)

 Hispanic

1.09

(0.90–1.34)

 Other

0.93

(0.80–1.08)

Marital status

0.01

 Married (ref)

 Not married

1.11

(1.02–1.21)

Prior cancer

0.87

 No (ref)

 Yes

1.02

(0.85–1.22)

State

<0.001

 CA (ref)

 GA

1.01

(0.87–1.17)

 KY

0.81

(0.68–0.95)

 NY

0.77

(0.66–0.90)

 OH

0.86

(0.73–1.00)

Area

0.36

 Rural (ref)

 Urban

0.92

(0.77–1.10)

<0.001

 1 (lowest (ref))

 2

0.99

(0.87–1.13)

 3

0.99

(0.87–1.12)

 4

0.93

(0.82–1.06)

 5 (highest)

0.76

(0.66–0.88)

Stage

0.43

 I (ref)

 II

1.05

(0.93–1.18)

Nodal involvement

0.36

 N0

1.09

(0.95–1.25)

 N1mic

0.97

(0.82–1.15)

 N1 (ref)

HER2 status

0.61

 Negative

0.95

(0.84–1.08)

 Borderline

1.08

(0.76–1.55)

 Unknown (ref)

Hormone receptor status

0.69

 ER and PR both positive (ref)

 Only ER or PR positive

1.02

(0.91–1.15)

Histological grade

0.17

 1–2 (well/moderately differentiated) (ref)

 3 (poorly or not differentiated)

1.07

(0.97–1.18)

One year comorbidities

0.01

 0 (ref)

 1 or more

1.17

(1.03–1.32)

Surgery type

0.79

 Breast-conserving surgery (ref)

 Mastectomy

1.01

(0.93–1.10)

Endocrine therapy

<0.001

 Tamoxifen only (ref)

 AIs only

0.77

(0.70–0.87)

 Tamoxifen and AIs

0.76

(0.68–0.85)

Chemotherapy

0.82

 Yes

1.01

(0.92–1.11)

 No (ref)