Table 3:

Multivariate Cox Proportional Hazard Ratio Model of Risk Factors for Mortality in Women with Stage IV Breast Cancer Enrolled in the SABCHO cohort (2015–2019), stratified by Self-Identified Ethnicity

	All Women		Black Women
Events (N)	421/542*		351/449**
	HR (95% CI)	P-value	HR (95% CI)	P-value
HIV
Negative	1.00		1.00
Positive	1.13 (0.89–1.44)	0.32	1.08 (0.84–1.40)	0.55
Age (years)
<50	1.00		1.00
≥50	1.16 (0.93– 1.46)	0.20	1.20 (0.94–1.53)	0.15
Hospitals
Durban	1.00		1.00
CHBAH	1.36 (1.00–1.86)	0.049	1.28 (0.89–1.83)	0.18
CMJAH	1.14 (0.83–1.56)	0.42	1.14 (0.79–1.65)	0.48
Greys	1.18 (0.87–1.61)	0.29	1.05 (0.73–1.51)	0.81
Ngwelazane	1.12 (0.64–1.95)	0.69	1.07 (0.58–1.98)	0.82
Performance Status
0 – 1	1.00		1.00
2 – 4	2.01 (1.60–2.53)	<0.001	2.09 (1.63–2.68)	<0.001
T stage
T0-T3	1.00		1.00
T4	1.60 (1.27–2.02)	<0.001	1.56 (1.20–2.01)	0.001
Hormone Receptor
Positive	1.00		1.00
Negative	1.39 (1.10–1.76)	0.006	1.46 (1.13–1.87)	0.003
HER2 Receptor
Negative	1.00		1.00
Positive	1.07 (0.85–1.35)	0.56	1.07 (0.83–1.37)	0.60
KI67 Index
≤20	1.00		1.00
>20	1.47 (1.18–1.83)	0.001	1.51 (1.19–1.93)	0.001
Metastatic site
Non-visceral	1.00		1.00
Visceral	1.31 (1.06–1.61)	0.01	1.34 (1.07–1.69)	0.01
Had surgery
No	1.00		1.00
Yes	0.50 (0.35–0.72)	<0.001	0.44 (0.29–0.67)	<0.001
Had systemic therapy
No	1.00		1.00
Yes	0.12 (0.09–0.16)	<0.001	0.12 (0.09–0.17)	<0.001

^*8 observations deleted due to missingness

^**6 observations deleted due to missingness