Table 5.

Multivariable analysis of predictive factors for occurrence of SSE.

	Odds ratio	95% CI	p value
agea	1.013	0.978–1.050	0.458
TN / HR positive	1.016	0.206–4.427	0.983
HER2 positive / HR positive	1.158	0.405–3.118	0.777
Presence of metastases	3.878	1.647–9.481	0.002
Bone only / Other
Bone metastases	2.454	0.985–6.792	0.054
Multiple / Local
Hormonal therapy prior to ZA	1.794	0.547–5.635	0.327
Yes / No
Chemotherapy prior to ZA	1.128	0.322–3.704	0.845
Yes / No
Hormonal therapy with ZA	1.746	0.641–5.225	0.282
Yes / No
Chemotherapy with ZA	3.116	1.052–10.682	0.040
Yes / No
The period from diagnosis of BC to the start of ZAa	1.022	0.949–1.113	0.577
The period of ZAa	1.000	1.000–1.002	0.074
SSE prior to ZA	2.041	0.743–5.460	0.163

Abbreviations: HR hormone receptor; TN triple negative; HER2 human epidermal growth factor 2 receptor, BC breast cancer,

ZA zoledronic acid.

^aContinuous variable.