Table 3.

Multivariate adjusted^† associations between sex-specific quartiles of total hip aBMD* and incident knee ROA and sROA, the Johnston County (JoCo OA) Project

Overall
	Knee ROA N=969				Knee sROA‡ N=1,133
	Number of Incident Cases	HR (95% CI)		P-trend¶	Number of Incident Cases		HR (95% CI)	P-trend¶
Quartiles total hip aBMD				0.120				0.325
1 (low aBMD)	47	Ref			28		Ref
2 (intermediate low aBMD)	71	1.57 (1.07, 2.15)			50		2.15 (1.40, 3.30)
3 (intermediate high aBMD)	72	1.64 (1.14, 2.36)			45		1.65 (1.02, 2.67)
4 (high aBMD)	55	1.33 (0.90, 1.99)			27		1.57 (0.86, 2.86)
Excluding Incident Knee Replacements
	Knee sROA‡ N=1,123
	Number of Incident Cases		HR (95% CI)			P-trend¶
Quartiles total hip a BMD						0.569
1 (low aBMD)	28		Ref
2 (intermediate aBMD)	48		2.03 (1.31, 3.13)
3 (intermediate aBMD)	39		1.44 (0.87, 2.37)
4 (high aBMD)	25		1.42 (0.76, 2.64)

Abbreviations: BMD, Bone Mineral Density; BMI, Body Mass Index; ROA, Radiographic Osteoarthritis; sROA, symptomatic Radiographic Osteoarthritis

^†All models adjusted for age, sex, race, education, BMI, smoking history, physical activity, history of knee injury, steroid use, and bisphosphonate use. Ns differed from analytic samples because of missing covariate values.

^‡Participants with 1 or neither condition (ROA and symptoms) in a hip at baseline were included

^¶A test of linear trend across quartiles of aBMD was performed based on the ordinal value for each quartile

Values are bolded to indicate statistical significance