Table 1.
Cohort description
| Observations: n | 126,064 |
|---|---|
| Gender: n (%) | |
| Female | 68,114 (54%) |
| Male | 49,306 (39%) |
| Not specified | 106 (0%) |
| Missing | 8538 (7%) |
| Age band: n (%) | |
| 40–49 years of age | 258 (0%) |
| 50–59 years of age | 11,380 (9%) |
| 60–69 years of age | 43,583 (35%) |
| 70–79 years of age | 48,073 (38%) |
| 80–89 years of age | 14,226 (11%) |
| 90+ years of age | 6 (0%) |
| Missing | 8538 (7%) |
| Pre-op OKS score1 | |
| Mean (SD) | 19.0 (8) |
| Median (IQR) | 19 (11) |
| Missing | 1473 (1%) |
| Pre-op EQ-5D index2 | |
| Mean (SD) | 0.414(0.31) |
| Median (IQR) | 0.587 (0.603) |
| Missing | 7077 (6%) |
| Pre-op EQ-5D VAS3 “Your own health state today” | |
| Mean (SD) | 68.2(20) |
| Median (IQR) | 70 (25) |
| Missing | 13,110 (10%) |
| “How would you describe the results of your operation?” n (%) | |
| Excellent | 31,827 (25%) |
| Very good | 44,472 (35%) |
| Good | 30,670 (24%) |
| Fair or Poor | 18,355 (15%) |
| Missing | 740 (1%) |
| “Overall, how are your problems now, compared to before your operation?” n (%) | |
| Much better | 92,164 (73%) |
| A little better | 20,276 (16%) |
| About the same | 5775 (5%) |
| A little or much worse | 7388 (6%) |
| Missing | 461 (0%) |
| Post-op OKS scorea | |
| Mean (SD) | 35.2 (10) |
| Median (IQR) | 37 (14) |
| Missing | 46 (0%) |
| Post-op EQ-5D indexb | |
| Mean (SD) | 0.734(0.25) |
| Median(IQR) | 0.760 (0.344) |
| Missing | 6084 (5%) |
| Post-op EQ-5D VASc “Your own health state today” | |
| Mean (SD) | 73.8 (20) |
| Median (IQR) | 80 (25) |
| Missing | 6746 (5%) |
acaptures knee pain and function, scored from 0 to 48 where 0 indicates most and 48 least pain and functional limitations
ba health-related quality of life measure where 0 represents death and 1 refers to perfect health
ca Visual Analogue Scale ranging from 0 to 100, where 0 represents the worst and 100 the best imaginable health state