Table 3. Parameter estimates for covariates in mediation analyses related to intervention condition, path ^β′.

	Regression parameter estimate (s.e.); P value
Covariate	Baseline to 1-year change in WOMAC pain (n = 1,755)	Baseline to 1-year change in WOMAC function (n = 1,756)	Baseline to 1-year change in WOMAC stiffness (n = 1,756)	Baseline to 1-year change in WOMAC summary (n = 1,756)
Age (years)	0.02 (0.01); P = 0.05	0.10 (0.04); P = 0.006	0.02 (0.005); P = 0.001	0.12 (0.05); P = 0.01
Female vs. male (reference)	0.62 (0.17); P = 0.003	1.94 (0.53); P = 0.0002	0.37 (0.08); P < 0.001	2.67 (0.73); P = 0.001
African-American vs. non-Hispanic white (reference)	0.52 (0.22); P = 0.02	0.65 (0.66); P = 0.32	0.09 (0.10); P = 0.40	1.10 (0.91); P = 0.23
Hispanic vs. non-Hispanic white (reference)	0.20 (0.32); P = 0.55	1.05 (0.98); P = 0.28	0.12 (0.15); P = 0.44	1.12 (1.36); P = 0.41
American Indian vs. non-Hispanic white (reference)	0.30 (1.12); P = 0.79	−6.67 (3.38); P = 0.05	−0.96 (0.53); P = 0.07	−7.48 (4.70); P = 0.11
Asian vs. non-Hispanic white (reference)	−0.17 (0.85); P = 0.84	−1.06 (2.56); P = 0.68	−0.14 (0.40); P = 0.72	−1.31 (3.56); P = 0.71
Other or mixed races vs. non-Hispanic white (reference)	1.22 (0.49); P = 0.01	3.47 (1.48); P = 0.02	0.36 (0.23); P = 0.12	5.02 (2.06); P = 0.01
Baseline Beck Depression Inventory-II	0.03 (0.01); P = 0.07	0.13 (0.05); P = 0.004	0.02 (0.01); P = 0.0004	0.15 (0.06); P = 0.02
NSAID use vs. no NSAID use (reference)	0.64 (0.16); P < 0.001	1.66 (0.49); P = 0.0007	0.30 (0.08); P < 0.001	2.36 (0.68); P = 0.005
Baseline score of outcome variable	−0.54 (0.03); P < 0.001	−0.51 (0.02); P < 0.001	−0.58 (0.02); P < 0.001	−0.47 (0.03); P < 0.001
Baseline weight (kg)	0.02 (0.004); P < 0.001	0.07 (0.01); P < 0.001	0.01 (0.002); P < 0.001	0.10 (0.02); P < 0.001

^β(s.e.) adjusted for intervention type and change in weight (kg) from baseline to 12 months.