Table 1.
Comparison of study cohort to patients without 1-year PROM data
| Group characteristic | Study cohort | Missing 1-year data | p value* |
|---|---|---|---|
| Number of patients | 562 | 188 | |
| Age (years)† | 67 (11) | 64 (11) | 0.005 |
| White | 76% | 67% | 0.058 |
| Female | 60% | 57% | 0.617 |
| Preoperative KOOS | 50 (18) | 48 (19) | 0.229 |
| Preoperative SF12v2 PCS | 32 (10) | 32 (10) | 0.573 |
| Preoperative SF12v2 MCS | 52 (12) | 51 (11) | 0.700 |
| Postoperative KOOS | 80 (18) | 80 (20)‡ | 0.948 |
| Postoperative SF12v2 PCS | 42 (12) | 40 (11)‡ | 0.137 |
| Postoperative SF12v2 MCS | 52 (10) | 53 (10)‡ | 0.639 |
* To compare the mean PROM scores of the study cohort with the mean PROM scores of those without 1-year data, a Student’s t-test was used and a Fisher’s exact test was used for categorical data; †mean (SD); ‡includes patients with at least one postoperative PROM score available (but missing 1-year PROM data). This group represented 32% (n = 60) of the total patients not included in the study cohort. Postoperative PROM scores included in the mean were those available from latest followup. This ranged from 2 to 4 years postoperatively; PROM = patient-reported outcome measures; KOOS = Knee injury and Osteoarthritis Outcome Score; SF12v2 = SF-12 version 2; PCS = physical component summary; MCS = mental component summary.