Table III.
Relative threshold values for knee arthroplasty at which patients have a 90%, 80%, 70%, or 50% probability of achieving the meaningful improvement criteria of seven points on the Oxford Knee Score, for both observed data and predictions from quantile regression.
Baseline covariate | Total patients | Predicted preoperative score corresponding to preselected percentage probability of improvement | Observed score | ||||||
---|---|---|---|---|---|---|---|---|---|
90% | 80% | 70% | 50% | 90% | 80% | 70% | 50% | ||
Total, n | 222,933 | N/A | 25 | 31 | 36 | 1 | 25 | 30 | 36 |
Age category, n | |||||||||
< 60 yrs | 29,349 | N/A | 18 | 29 | 35 | 1 | 21 | 30 | 35 |
60 to 80 yrs | 164,132 | N/A | 26 | 31 | 36 | 1 | 26 | 31 | 36 |
> 80 yrs | 29,452 | 13 | 24 | 30 | 35 | 15 | 26 | 30 | 36 |
Sex, n* | |||||||||
Male | 96,006 | N/A | 26 | 31 | 36 | 0 | 26 | 32 | 36 |
Female | 126,885 | N/A | 25 | 30 | 35 | 1 | 25 | 30 | 36 |
Year of NHS PROMs, n | |||||||||
2009 to 2011 | 102,448 | N/A | 24 | 30 | 35 | 1 | 23 | 30 | 36 |
2012 to 2015 | 120,485 | N/A | 27 | 31 | 36 | 1 | 26 | 32 | 36 |
Data missing for 42 patients.
N/A, not applicable; PROMs, patient-reported outcome measures.