. 2019 Mar 8;2(3):e190429. doi: 10.1001/jamanetworkopen.2019.0429

Table 3. Stratified Univariable and Multivariable Analysis of Hazard Ratios for Developing Bone Metastasis.

Variable	Univariable Analysis		Multivariable Analysis^a
Variable	HR (95% CI)	P Value	Adjusted HR (95% CI)	P Value
Bisphosphonates^b
Osteoporosis treatment	2.01 (1.39-2.93)	<.001	1.47 (1.00-2.17)	.05
Age at breast cancer diagnosis	NA	NA	1.02 (1.02-1.03)	<.001
Age >55 y^c
Osteoporosis treatment	1.64 (1.11-2.43)	.01	1.46 (0.98-2.18)	.06
Age at breast cancer diagnosis	NA	NA	1.02 (1.00-1.03)	.008
Age ≤55 y^d
Osteoporosis treatment	0.84 (0.37-1.91)	.68	0.83 (0.36-1.89)	.65
Age at breast cancer diagnosis	NA	NA	1.00 (0.98-1.02)	.70
Other osteoporosis drugs^e
Osteoporosis treatment	1.10 (0.79-1.53)	.56	1.00 (0.72-1.39)	>.99
Age at breast cancer diagnosis	NA	NA	1.03 (1.02-1.03)	<.001
Age >55 y^f
Osteoporosis treatment	1.05 (0.73-1.51)	.80	1.03 (0.72-1.48)	.87
Age at breast cancer diagnosis	NA	NA	1.02 (1.01-1.03)	<.001
Age ≤55 y^g
Osteoporosis treatment	1.09 (0.53-2.22)	.81	1.09 (0.53-2.22)	.81
Age at breast cancer diagnosis	NA	NA	1.00 (0.98-1.02)	.74

Abbreviations: HR, hazard ratio; NA, not applicable.

^{^a}

Models adjusted for age.

^{^b}

The exposed group included 29 of 337 patients (8.6%) with bone metastasis; the unexposed group included 518 of 10 678 patients (4.8%) with bone metastasis.

^{^c}

The exposed group included 27 of 321 patients (8.4%) with bone metastasis; the unexposed group included 370 of 6711 patients (5.5%) with bone metastasis.

^{^d}

The exposed group included 2 of 16 patients (12.5%) with bone metastasis; the unexposed group included 148 of 3967 patients (3.7%) with bone metastasis.

^{^e}

The exposed group included 38 of 689 patients (5.5%) with bone metastasis; the unexposed group included 518 of 10 678 patients (4.8%) with bone metastasis.

^{^f}

The exposed group included 32 of 541 patients (5.9%) with bone metastasis; the unexposed group included 370 of 6711 patients (5.5%) with bone metastasis.

^{^g}

The exposed group included 6 of 148 patients (4.1%) with bone metastasis; the unexposed group included 148 of 3967 patients (3.7%) with bone metastasis.