Table 3.

Fracture rates by age group

Patients < 65 years
	GR patients			Other patients
	n = 1,896			n = 1,896			IRR (95% CI)a,b Unadjusted
	Total number of fractures	Total patient-years of observation	IR of fractures, per 1,000 patient-years	Total number of fractures	Total patient-years of observation	IR of fractures, per 1,000 patient-years
Any site	192	8,104	23.69	214	8,783	24.37	0.96 (0.75–1.24)
Hip	36	8,104	4.44	22	8,783	2.50	1.80 (0.85–3.83)
Pelvis	4	8,104	0.49	9	8,783	1.02	0.48 (0.14–1.69)
Spine	45	8,104	5.55	69	8,783	7.86	0.67 (0.42–1.08)
Wrist/arm	114	8,104	14.07	120	8,783	13.66	1.03 (0.77–1.37)
Patients ≥ 65 years
	GR patients			Other patients
	n = 830			n = 830			IRR (95% CI)a,b Unadjusted
	Total number of fractures	Total patient-years of observation	IR of fractures, per 1,000 patient-years	Total number of fractures	Total patient-years of observation	IR of fractures, per 1,000 patient-years
Any site	217	3,700	58.65	326	4,035	80.79	0.74 (0.60–0.91)*
Hip	64	3,700	17.30	92	4,035	22.80	0.78 (0.52–1.17)
Pelvis	24	3,700	6.49	34	4,035	8.43	0.78 (0.42–1.42)
Spine	83	3,700	22.43	125	4,035	30.98	0.74 (0.52–1.05)
Wrist/arm	66	3,700	17.84	95	4,035	23.54	0.76 (0.55–1.05)

Notes:

CI confidence interval, IR incidence rate, IRR incidence rate ratio

^aIncidence rate ratios were estimated with generalized linear models with log link and negative binomial distribution with robust error variances to account for the matched pairs. Incidence rate ratios may differ from the ratio of the incidence rates because of adjustments for overdispersion

^bAn IRR < 1 indicates a lower incidence of fracture per patient-year among women treated with risedronate GR

^*Significant at the 5% level