Table 1.
Descriptive demographic characteristics, comparing patients included in the analysis with a 6-month post-operative OKS, with all patients with baseline data.
| All patients |
Included in analysis (Post op OKS-PS) |
Excluded from analysis |
|
|---|---|---|---|
| N = 531,790 | N = 258,386 | N = 273,404 | |
| Year of primary | |||
| 2007 & 2008 | 34,151 (6.4%) | 3764 (1.5%) | 30,387 (11.1%) |
| 2009 | 46,857 (8.8%) | 19,048 (7.4%) | 27,809 (10.2%) |
| 2010 | 53,145 (10.0%) | 30,240 (11.7%) | 22,905 (8.4%) |
| 2011 | 57,256 (10.8%) | 33,775 (13.1%) | 23,481 (8.6%) |
| 2012 | 60,696 (11.4%) | 35,703 (13.8%) | 24,993 (9.1%) |
| 2013 | 62,168 (11.7%) | 37,807 (14.6%) | 24,361 (8.9%) |
| 2014 | 69,697 (13.1%) | 41,780 (16.2%) | 27,917 (10.2%) |
| 2015 | 70,908 (13.3%) | 40,563 (15.7%) | 30,345 (11.1%) |
| 2016 | 72,304 (13.6%) | 15,264 (5.9%) | 57,040 (20.9%) |
| 2017 | 4608 (0.9%) | 442 (0.2%) | 4166 (1.5%) |
| Age at primary knee replacement | 69.7 (SD 9.4) | 70.1 (SD 8.8) | 69.4 (SD 9.9) |
| Sex | |||
| Female | 301,224 (56.6%) | 146,510 (56.7%) | 154,714 (56.6%) |
| Male | 230,566 (43.4%) | 43.36 (100.0%) | 118,690 (43.4%) |
| Body mass index | 31.0 (SD 5.5) | 31.0 (SD 5.4) | 30.9 (SD 5.5) |
| Index of Multiple Deprivation (IMD) quintiles | |||
| Most deprived | 77,215 (14.5%) | 34,653 (13.4%) | 42,562 (15.6%) |
| 2 | 96,500 (18.2%) | 45,298 (17.5%) | 51,202 (18.7%) |
| 3 | 116,429 (21.9%) | 57,301 (22.2%) | 59,128 (21.6%) |
| 4 | 121,791 (22.9%) | 61,262 (23.7%) | 60,529 (22.1%) |
| Least deprived | 114,664 (21.6%) | 57,251 (22.2%) | 57,413 (21.0%) |
| ASA grade | |||
| P1 - Fit and healthy | 51,437 (9.7%) | 23,717 (9.2%) | 27,720 (10.1%) |
| P2 - Mild disease not incapacitating | 392,501 (73.8%) | 194,989 (75.5%) | 197,512 (72.2%) |
| P3 - Incapacitating systemic disease | 86,314 (16.2%) | 39,061 (15.1%) | 47,253 (17.3%) |
| P4 – P5 - Life threatening disease/Expected to die within 24 h s | 1538 (0.3%) | 619 (0.2%) | 919 (0.3%) |