. Author manuscript; available in PMC: 2013 Apr 1.

Published in final edited form as: J Bone Miner Res. 2012 Apr;27(4):808–816. doi: 10.1002/jbmr.1539

Table 4.

Relative Hazard for each quartile, normalized with respect to the lowest-risk quartile, all adjusted for age (95% confidence intervals in parentheses).

Predictor	Relative Hazard for each Quartile^†
	Q1	Q2	Q3	Q4
LS aBMD	14.3 (4.1–49.7)	7.5 (2.1–27.0)	3.2 (0.8–12.4)	1.0
Integral vBMD	26.9 (6.2–116)	10.9 (2.4–48.8)	3.9 (0.8–19.5)	1.0
Vertebral Strength	27.3 (6.2–120)	8.9 (1.9–40.8)	3.5 (0.7–17.5)	1.0
Load-to-Strength Ratio	1.0	2.1 (0.5–8.6)	6.4 (1.8–23.1)	19.6 (5.7–67.7)
Strength-to-Density Ratio	42.3 (5.5–326)	22.6 (2.9–177)	9.6 (1.2–77.6)	1.0

See Table 1 for legends and units.

^†

Q1 is taken as the lowest quartile, having the lowest absolute values of the predictor variable; Q4 has the highest values. For the calculation of relative hazards, the quartile with the lowest risk is the referent, and has its relative hazard set to unity; this referent quartile is Q4 for all predictors except for the load-to-strength ratio, for which it is Q1.