Table II.
Relative threshold values for hip arthroplasty at which 90%, 80%, 70%, and 50% of subjects achieved the meaningful improvement criteria of eight points on the Oxford Hip 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 | 209,761 | 223 | 32 | 35 | 38 | 24 | 31 | 35 | 38 |
| Age category, n | |||||||||
| < 60 yrs | 37,904 | 26 | 33 | 36 | 38 | 27 | 32 | 38 | 38 |
| 60 to 80 yrs | 144,064 | 24 | 32 | 35 | 38 | 24 | 32 | 35 | 38 |
| > 80 yrs | 27,793 | 19 | 27 | 32 | 36 | 19 | 26 | 31 | 36 |
| Sex, n* | |||||||||
| Male | 84,673 | 25 | 32 | 35 | 38 | 26 | 33 | 35 | 38 |
| Female | 125,058 | 22 | 31 | 34 | 38 | 23 | 31 | 35 | 38 |
| Year of NHS PROMs, n | |||||||||
| 2009 to 2011 | 96,041 | 22 | 31 | 34 | 38 | 20 | 31 | 35 | 38 |
| 2012 to 2015 | 113,720 | 25 | 32 | 35 | 38 | 25 | 31 | 35 | 38 |
*
Data missing for 30 patients.
PROMs, patient-reported outcome measures.