Table 3.

Hazard Ratios for Atypical Femur Fracture in a Cohort of Women with Bisphosphonate Use.^*

Risk Factor	Hazard Ratio (95% CI)
	Unadjusted	Multivariate-Adjusted
Age (yr)
50–64	0.97 (0.55–1.71)	1.59 (0.87–2.91)
65–74	2.36 (1.42–3.92)	2.76 (1.62–4.72)
75–84	2.48 (1.48–4.15)	2.50 (1.47–4.23)
≥85	Reference	Reference
Race or ethnic group
Asian	5.38 (4.12–7.01)	4.84 (3.57–6.56)
White	Reference	Reference
Other	0.92 (0.65–1.29)	0.99 (0.70–1.42)
Duration of bisphosphonate use (yr)
0 to <0.25	Reference	Reference
0.25 to <3	7.56 (2.67–21.47)	2.54 (0.79–8.14)
3 to <5	33.76 (12.07–94.48)	8.86 (2.79–28.20)
5 to <8	80.90 (29.22–224.01)	19.88 (6.32–62.49)
≥8	179.51 (64.64–498.52)	43.51 (13.70–138.15)
Time since last bisphosphonate use (yr)
≤0.25: current user	Reference	Reference
>0.25–1.25	0.38 (0.27–0.52)	0.52 (0.37–0.72)
>1.25–4	0.12 (0.07–0.20)	0.21 (0.13–0.34)
>4	0.08 (0.05–0.15)	0.26 (0.14–0.48)
Not yet used	0.01 (0.00–0.06)	0.09 (0.01–0.83)
Ever smoked
Yes	0.40 (0.22–0.76)	0.64 (0.34–1.22)
No	Reference	Reference
Height (per 5-cm decrement)	1.39 (1.28–1.52)	1.28 (1.15–1.43)
Weight (per 5-kg increment)	0.94 (0.91–0.98)	1.15 (1.11–1.19)
Any previous fracture
Yes	1.27 (0.87–1.84)	1.28 (0.86–1.89)
No	Reference	Reference
Body-mass index (per 1-unit change)†	1.00 (0.98–1.02)
Glucocorticoid use (yr)
None	Reference	Reference
>0 to <1	1.16 (0.90–1.49)	1.10 (0.85–1.42)
≥1	2.57 (1.72–3.83)	2.28 (1.52–3.43)

^*Any variable with a P value of more than 0.2 in the univariate model was included in the multivariate model. For continuous variables (height and weight), entry to the multivariate model was determined by P value for continuous univariate analysis.

^†Height and weight but not body-mass index were included in the multivariate model.