. Author manuscript; available in PMC: 2011 Jul 1.

Published in final edited form as: Osteoarthritis Cartilage. 2010 Mar 24;18(7):883–887. doi: 10.1016/j.joca.2009.11.016

Table 1.

Subject Characteristics

Characteristic	Subjects (n=266)	Case-crossover Subjects (n=91)
Age, years [mean (SD)]	65(±8.5)	65(±8.8)
Female [n (%)]	191 (71)	72 (79)
BMI, kg/m2 [mean (SD)]	31.5 (±7.4)	31.4 (±8.8)
Race – Non-Hispanic White	89%	89%
Race – African-American	6%	8%
Race – Other	5%	3%
Knee as primary site [n (%)]	216 (82)	71 (78)
Hip as primary site [n (%)]	50 (18)	20 (22)
WOMAC range	0.2-9.6	0.2-4.9 (control periods) 5.0-9.6 (case periods)
WOMAC [mean(SD)]	3.8 (±2.2)	4.5 (±1.8)
MHI-5 [mean (SD)]	25.1 (±4.0)	24.7 (±4.0)