TABLE-2.

Cox Regression Model Using Trastuzumab As a Time-Dependent Variable to Evaluate the Risk of Cardiotoxicity Among Breast Cancer Patients diagnosed between 2009–2014 (N=16456).

Patient Characteristic	Crude HR (95% CI)		Adjusted HR (95% CI)
Age, years
65+	Ref		Ref
≤35	0.09	(0.01 – 0.66)	0.37	(0.19 – 0.72)
36–49	0.38	(0.26 – 0.55)	0.49	(0.38 – 0.62)
50–64	0.49	(0.38 – 0.63)	0.52	(0.44 – 0.63)
Year of Diagnosis
2009	Ref		Ref
2010	1.02	(0.75 – 1.39)	0.91	(0.72 – 1.15)
2011	1.04	(0.75 – 1.44)	1.03	(0.82 – 1.30)
2012	0.99	(0.69 – 1.43)	0.98	(0.76 – 1.27)
2013	0.93	(0.61 – 1.40)	1.16	(0.90 – 1.50)
2014	1.13	(0.71 – 1.80)	0.98	(0.72 – 1.33)
Trastuzumab
No	Ref		Ref
Yes	1.83	(1.57 – 2.13)	2.01	(1.72 – 2.36)
Anthracyclines
No	Ref		Ref
Yes	1.74	(1.39 – 2.16)	1.53	(1.30 – 1.80)
Taxanes
No	Ref		Ref
Yes	0.70	(0.53 – 0.94)	0.81	(0.65 – 1.01)
Radiation
No	Ref		Ref
Yes	0.79	(0.63 – 0.99)	0.95	(0.81 – 1.11)
Deyo Comorbidity Score
0	Ref		Ref
1	1.50	(1.11 – 2.02)	1.38	(1.15 – 1.66)
2+	3.04	(2.08 – 4.45)	2.47	(1.94 – 3.15)
Hypertension
No	Ref		Ref
Yes	1.63	(1.28 – 2.08)	1.28	(1.09 – 1.51)
Valve Disease
No	Ref		Ref
Yes	2.05	(1.45 – 2.90)	1.93	(1.48 – 2.51)
Insurance
PPO	Ref		Ref
HMO	1.09	(0.78 – 1.53)	1.12	(0.89 – 1.41)
Other	1.23	(0.97 – 1.56)	1.09	(0.92 – 1.29)
Region
Northeast	Ref		Ref
North Central	1.25	(0.88 – 1.76)	0.90	(0.72 – 1.12)
South	1.13	(0.81 – 1.57)	0.72	(0.58 – 0.89)
Unknown	1.65	(0.74 – 3.68)	0.74	(0.39 – 1.42)
West	0.99	(0.66 – 1.50)	0.82	(0.64 – 1.05)