Interaction between relationship satisfaction and partner’s daily steps on participants with osteoarthritis’ daily steps. Figure shows the association between the partner’s daily steps and participant’s daily steps by relationship satisfaction at 1 SD below the mean (IRR = 1.001, 95% CI = 0.998, 1.004), the mean (IRR = 1.004, 95% CI = 1.001, 1.006), and 1 SD above the mean (IRR = 1.007, 95% CI = 1.003, 1.011). Note: PA = physical activity, SD = standard deviation