Table 3.

Mediation effects for outcome WOMAC pain over 24 months: Association of change in cartilage thickness loss over 24 months, with change in WOMAC knee

Exposure: cartilage thickness loss over 24 months	Mediator: synovitis score change over 24 months Mean change in WOMAC Knee pain over 24 months*	Mediator: BML score change over 24 months Mean change in WOMAC Knee pain over 24 months*
Exposure: 0.1 mm Cartilage Thickness Loss over 24 months
Controlled Direct Effect	0.28 (−1.68, 2.24)**	0.33 (−1.62, 2.30)**
Indirect Effect	0.05 (−1.91, 2.01)	0.01(−1.95, 1.97)
Total Effect	0.33 (−1.63, 2.29)	0.34(−1.62, 2.30)
Proportion Mediated	14.11% (2.07%, 26.15%)	2.77% (−1.71%, 7.25%)
Exposure: 0.05 mm Cartilage Thickness Loss over 24 months
Controlled Direct Effect	0.14 (−1.82, 2.10)	0.17 (−1.79, 2.13)
Indirect Effect	0.02 (−1.92, 1.98)	0.004(−1.96, 1.96)
Total Effect	0.16 (−1.80, 2.12)	0.17(−1.79, 2.13)
Proportion Mediated	14.11% (2.07%, 26.15%)	2.77% (−1.71%, 7.25%)

^*All models adjusted for age, sex, BMI, race, depressive symptoms (CESD), baseline WOMAC pain.

^**Values are unstandardized regression coefficients representing mean change in WOMAC knee pain over 24 months.

Positive(+) coefficient indicates an increase in the outcome WOMAC pain.

Models for mediation by change in synovitis score adjusted for standard covariates above + baseline BML score.

Models for mediation by change in BML score adjusted for standard covariates above + baseline synovitis score.