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

Published in final edited form as: Arthritis Care Res (Hoboken). 2012 Sep;64(9):1292–1300. doi: 10.1002/acr.21705

Table 1. Comparison of Demographic Values for Surgical vs. Non-Surgical Subjects.

Demographic variables	SMPA (N=67)	Non-SMPA (N=95)	P- value
Age, mean (SD)	60 (8)	62 (11 )	0.24
Male, No. (%)	12 (18)	32 (35)	0.03
Race, White, No. (%)^a	58 (94)	79 (86)	0.14
Education, ≤ High School Degree, No. (%)^a	35 (56)	38 (41)	0.07
Income, ≤ $50,000, No. (%)^a	47 (77)	60 (68)	0.24

Eight (5%) participants are missing race and education data and 13 (8%) are missing income data.