Table 3.

Yearly BSI Rates in Trabecular- and Cortical-Rich Bone Sites

	Cortical-Rich BSI						Trabecular-Rich BSI
Phase	N	BSI Events	Person-Years	Crude Rate	Adjusted Rate	95% CI	BSI Events	Person-Years	Crude Rate	Adjusted Rate	95% CI
Historical
Year 1	35	9	29.9	0.30	0.26	0.14–0.49	9	29.9	0.30	0.27	0.14–0.54
Year 2	36	6	32.1	0.19	0.15	0.06–0.43	8	32.1	0.25	0.24	0.12–0.49
Year 3	31	5	28.1	0.18	0.14	0.05–0.36	11	28.1	0.39	0.44	0.21–0.93
Total	56	20	90.2	0.22	0.18	0.11–0.32	28	90.2	0.31	0.31	0.19–0.49
Pilot
Year 1	30	1	28.6	0.04	0.03	0.05–0.18	4	28.6	0.14	0.16	0.08–0.35
Year 2	34	8	29.8	0.27	0.23	0.99–0.53	11	29.8	0.37	0.34	0.17–0.66
Year 3	44	8	36.8	0.22	0.20	0.10–0.38	11	36.8	0.30	0.25	0.12–0.50
Total	66	17	95.2	0.18	0.16	0.09–0.26	26	95.2	0.27	0.24	0.16–0.37
Intervention*†
Year 1	49	5	42.7	0.12	0.11	0.05–0.26	26	42.7	0.61	0.52	0.32–0.85
Year 2	43	5	38.2	0.13	0.13	0.05–0.30	8	38.2	0.21	0.17	0.08–0.38
Year 3	38	2	34.6	0.06	0.05	0.01–0.20	8	34.6	0.23	0.20	0.09–0.46
Year 4	36	2	21.9	0.09	0.09	0.02–0.35	6	21.9	0.27	0.28	0.14–0.57
Total	78	14	137.3	0.10	0.10	0.17–0.44	48	137.3	0.35	0.31	0.22–0.46

*p-value for historical vs. intervention for trabecular bone = 0.047.

†p-value for his historical vs. intervention for cortical bone = 0.87.