Table 3.
Time-weighted average (TWA) of patient-reported outcomes (PROs) over the entire observation period (from pre-surgery to 2 years post-surgery or dropout). The unadjusted TWA are presented with 95% confidence interval (CI). Mean differences between groups are presented when adjusted for differences in age, sex, BMI, and baseline PRO score
| PROs | Persona TWA (CI) (n = 155) a | NexGen TWA (CI) (n = 154) a | Adjusted mean difference b (CI) | P value |
|---|---|---|---|---|
| Oxford Knee Score | 36.6 (35.5–37.7) | 36.4 (35.4–37.4) | – 0.1 (–1.5 to 1.2) | 0.9 |
| Oxford Knee Score – APQ | 60.6 (56.4–64.8) | 57.9 (53.8–62.0) | –1.9 (–7.5 to 3.7) | 0.5 |
| Forgotten Joint Score | 52.7 (48.8–56.6) | 51.5 (47.9–55.1) | –0.6 (–5.7 to 4.5) | 0.8 |
| EQ-5D-3L Index | 0.83 (0.81–0.85) | 0.83 (0.81–0.85) | 0.01 (–0.02 to 0.03) | 0.7 |
| EQ-5D-3L VAS | 78 (75–80) | 77 (75–79) | –1.1 (–3.9 to 1.7) | 0.4 |
APQ = Activity and Participation Questionnaire
2 patients (1 Persona, 1 NexGen) had no postoperative PROs at any follow-up, which is why TWA could not be calculated for these patients. 1 further patient (NexGen) had too many missing values in FJS, which is why n(FJS) = 153 for the NexGen-group.
Difference in mean when adjusted for age, sex, BMI, and baseline score. 1 patient (NexGen) had no baseline value recorded. Model is run with baseline value missing.