Table 1 Missing data and implausible values in EHRs for model predictors and outcomes
Study cohort (N = 201,462) | Missing data | Implausible data entries | |
|---|---|---|---|
Characteristics | n (%) | n (%) | n (%) |
Predictors | |||
Age (years)—mean (SD) | 67.2 (11.1) | 3 (0.001) | – |
BMI—mean (SD) | 30.1 (6.5) | 137,071 (68.0) | 224 (0.1) |
Weight gain between early adulthood and middle age—mean (SD) | – | 201,462 (100.0) | – |
Weight early adulthood—mean (SD) | – | 201,462 (100.0) | – |
Weight middle age—mean (SD) | 85.3 (20.1) | 113,561 (56.4) | 135 (0.07) |
OA medication prescription/s | 57,090 (33.8) | 32,548 (16.2) | 43 (0.02) |
Multimorbidity | |||
CCI count—Median (IQR) | 0 [0,1] | 15,875 (7.9) | N/A |
BEACH count^—Median (IQR) | 2 [1, 4] | 51,035 (25.3) | N/A |
Combined CCI and BEACH count^—Median (IQR) | 2 [1, 4] | 51,876 (25.7) | N/A |
Mental health condition | 46,859 (24.2) | 8178 (4.1) | N/A |
Previous/contralateral knee replacement | 9432 (4.7) | 1254 (0.6) | 10 (0.005) |
Any past knee surgery on either knee (excluding TKR) | 6070 (3.0) | 990 (0.5) | 17 (0.01) |
Patient geographical residence* | 1068 (0.5) | N/A | |
Major cities of Australia | 111,075 (55.4) | ||
Inner regional Australia | 62,221 (31.1) | ||
Remote Australia | 27,098 (13.5) | ||
Outcome | |||
TKR during study | 8638 (4.3) | 1259 (0.6) | 7 (0.003) |
TKR year | 1259 (0.6) | 7 (0.003) | |
2014 | 2282 (26.4) | ||
2015 | 2186 (25.3) | ||
2016 | 2171 (25.1) | ||
2017 | 1999 (23.1) | ||
TKR side | 9134 (92.2) | ||
Left | 326 (42.3) | ||
Right | 358 (46.5) | ||
Bilateral | 86 (11.2) | ||
Competing risk | |||
Recorded as “deceased” in EHR | 9581 (4.8) | – | – |
Recorded year of death of those recorded as deceased in the EHR | 7720 (80.6) | 1861 (19.4) | – |
Recorded as prior to baseline | 271 (3.5) | ||
2014 | 1445 (18.7) | ||
2015 | 1866 (24.2) | ||
2016 | 2060 (26.7) | ||
2017 | 2078 (26.9) | ||
General practice clinics (n = 483) | |||
Median (IQR) number of patients with OA per clinic | 327 [181, 566] | – | – |
Clinic state | – | – | |
New South Wales | 71,397 (35.4) | ||
Queensland | 38,498 (19.1) | ||
Victoria | 36,189 (18.0) | ||
Western Australia | 22,570 (11.2) | ||
Tasmania | 21,247 (10.6) | ||
South Australia | 6018 (3.0) | ||
Australian Capital Territory | 4168 (2.1) | ||
Northern Territory | 1375 (0.7) | ||
Clinic geographical location* | 71 (0.04) | ||
Major cities of Australia | 114,203 (56.7) | ||
Inner regional Australia | 61,501 (30.5) | ||
Remote Australia | 25,687 (12.8) |