Table 2.

Cumulative annual incidence of first and subsequent skeletal-related events for the intention-to-treat population after randomisation

	Skeletal-related events		Incidence (95% CI)		Overall difference (95% CI) between clodronic acid and zoledronic acid*	p value for preceding 12 months†
	Clodronic acid (n=979)	Zoledronic acid (n=981)	Clodronic acid (n=979)	Zoledronic acid (n=981)
12 months	451 (46%)	333 (34%)	0·43 (0·38–0·48)	0·33 (0·28–0·37)	0·11 (0·04–0·18)	0·0002
24 months	93 (9%)	54 (6%)	0·60 (0·53–0·66)	0·42 (0·36–0·48)	0·18 (0·09–0·26)	0·0024
36 months	28 (3%)	16 (2%)	0·69 (0·61–0·78)	0·47 (0·40–0·53)	0·23 (0·12–0·33)	0·0089
48 months	13 (1%)	4 (<1%)	0·80 (0·68–0·91)	0·49 (0·42–0·56)	0·30 (0·17–0·44)	0·0510
60 months	2 (<1%)	2 (<1%)	0·83 (0·70–0·95)	0·51 (0·43–0·58)	0·32 (0·18–0·46)	0·5359

Data are number (%), unless otherwise indicated.

^*p<0·0001.

^†Unadjusted p value for the comparison of incidence of skeletal-related events in zoledronic acid group versus clodronic acid group per 12 months (eg, 24-month p value is for incidence between 12 months and 24 months).