Results
The study included 3697 patients with hip replacement (mean [SD] age, 65.8 [10.6] years; 2065 women [55.9%]) and 3110 patients with knee replacement (mean [SD] age, 66.0 [9.2] years; 1669 women [53.7%]). Exploratory analyses showed significantly better health outcomes in the intervention group on all PROMs except the EQ-5D-5L among patients with hip replacement, with a 2.10-point increase on the EQ-VAS in the intervention group compared with the control group (HOOS-PS, −1.86 points; PROMIS-fatigue, −0.69 points; PROMIS-depression, −0.57 points). Patients in the intervention group with knee replacement had a 1.24-point increase on the EQ-VAS, as well as significantly better scores on the KOOS-PS (−0.99 points) and PROMIS-fatigue (−0.84 points) compared with the control group. Mixed-effect models showed a significant difference in improvement on the EQ-VAS (hip replacement: effect estimate [EE], 1.66 [95% CI, 0.58-2.74]; knee replacement: EE, 1.71 [95% CI, 0.53-2.90]) and PROMIS-fatigue (hip replacement: EE, −0.65 [95% CI, −1.12 to −0.18]; knee replacement: EE, −0.71 [95% CI, −1.23 to −0.20]). The PROMIS-depression score was significantly reduced in the hip replacement group (EE, −0.60 [95% CI, −1.01 to −0.18]).