Impact of Insurance Coverage on Outcomes in Primary Breast Sarcoma

Table 4

Univariate and multivariate Cox proportional hazard models.

Variable	Univariate analysis		Multivariate analysis
	HR (95% CI)		HR (95% CI)
Insurance coverage
Private	Reference		Reference
Medicaid	3.01 (2.04–4.45)	<0.001	2.47 (1.62–3.77)	<0.001
Medicare	2.55 (1.94–3.33)	<0.001	1.68 (1.10–2.57)	0.017
Age (years)
18–44	Reference		Reference
45–54	1.34 (0.87–2.06)	0.187	1.20 (0.76–1.89)	0.435
55–64	1.34 (0.86–2.08)	0.194	1.52 (0.95–2.43)	0.081
≥65	2.40 (1.65–3.50)	<0.001	2.03 (1.20–3.43)	0.008
Race
White	Reference		Reference
Black	0.90 (0.63–1.27)	0.543	0.65 (0.43–0.98)	0.040
Other/unknown	0.43 (0.23–0.81)	0.009	0.45 (0.24–0.87)	0.018
Year of diagnosis
2004-2005	Reference		Reference
2006-2007	0.80 (0.54–1.18)	0.256	0.70 (0.47–1.06)	0.095
2008-2009	1.31 (0.92–1.87)	0.130	1.04 (0.71–1.51)	0.843
2010-2011	1.27 (0.87–1.86)	0.220	0.68 (0.44–1.03)	0.066
2012-2013	0.94 (0.60–1.49)	0.802	0.74 (0.46–1.18)	0.207
Charlson–Deyo score
0	Reference		Reference
1	1.19 (0.86–1.66)	0.291	1.13 (0.77–1.63)	0.535
≥2	3.28 (1.67–6.42)	0.001	1.40 (0.68–2.92)	0.363
Income
<$38,000	Reference		Reference
≥$38,000	0.77 (0.57–1.05)	0.099	0.95 (0.65–1.39)	0.795
Residence type
Metropolitan	Reference		Reference
Urban/rural	1.21 (0.85–1.72)	0.282	1.01 (0.67–1.53)	0.956
Distance from facility
≤50 miles	Reference		Reference
>50 miles	0.93 (0.61–1.43)	0.741	0.72 (0.45–1.16)	0.179
Educational attainment (% without HSD)
≥13%	Reference		Reference
<13%	0.87 (0.67–1.11)	0.255	0.89 (0.66–1.19)	0.415
Angiosarcoma
Yes	Reference		Reference
No	0.96 (0.74–1.24)	0.755	0.82 (0.62–1.10)	0.183
Tumor size category
T1: ≤5 cm	Reference		Reference
T2: >5 cm	3.26 (2.47–4.30)	<0.001	3.66 (2.66–5.02)	<0.001
Unknown	1.72 (1.08–2.74)	0.022	1.56 (0.95–2.54)	0.079
Node status
N0	Reference		Reference
N+	1.54 (0.75–3.16)	0.239	1.43 (0.67–3.06)	0.348
No nodes examined/unknown	0.98 (0.76–1.26)	0.880	0.92 (0.70–1.23)	0.586
Metastatic status
M0	Reference		Reference
M1	7.20 (5.19–10.00)	<0.001	7.19 (4.69–11.03)	<0.001
Grade
G1: well differentiated	Reference		Reference
G2: moderately differentiated	1.36 (0.78–2.38)	0.280	1.49 (0.83–2.69)	0.181
G3: poorly, undifferentiated, or anaplastic	2.67 (1.74–4.12)	<0.001	2.23 (1.39–3.58)	0.001
Unknown	2.04 (1.25–3.30)	0.004	1.89 (1.14–3.13)	0.014
Treatment summary
No definitive treatment	Reference		Reference
Surgery alone	0.31 (0.18–0.53)	<0.001	0.20 (0.11–0.37)	<0.001
Surgery and RT	0.27 (0.15–0.47)	<0.001	0.12 (0.06–0.23)	<0.001
Other/unknown	0.60 (0.34–1.07)	0.083	0.22 (0.11–0.43)	<0.001

Abbreviations: HR, hazard ratio; CI, confidence interval; HSD, high school degree; RT, radiation therapy.