Table 1 Comparison of pre-operative status for primary total hip replacement patients
Variable | Revised at 6–24 months (n = 88) | Not revised at 6–24 months (n = 21,148) | p-value |
|---|---|---|---|
Demographic and clinical characteristics | Â | Â | Â |
 Age in years, mean (SD) | 65 (11) | 66 (11) | 0.50 |
 Body mass index, mean (SD) | 31 (6) | 30 (7) | 0.14 |
 Female, n (%) | 45 (51) | 11,536 (55) | 0.52 |
 ASA grade |  |  | 0.61 |
  I (Healthy) | 7 (8) | 1,613 (8) |  |
  II (Mild systemic disease) | 44 (50) | 11,859 (56) |  |
  III (Severe systemic disease) | 35 (40) | 7,401 (35) |  |
  IV (Severe systemic disease, threat to life) | 2 (2) | 204 (1) |  |
  V (Moribund patient) | 0 (0) | 2 (< 1) |  |
 Primary diagnosis, n (%) |  |  | NR |
  Osteoarthritis | 74 (84) | 19,712 (93) |  |
  Osteonecrosis | 9 (10) | 690 (3) |  |
  Other | 5 (6) | 746 (4) |  |
Pre-operative scores | Â | Â | Â |
 Hip pain VAS, mean (SD) | 7.2 (2.0) | 6.8 (2.1) | 0.13 |
 Low back pain VAS, mean (SD) | 5.0 (3.1) | 4.2 (3.0) | 0.02 |
 Oxford Hip Score, mean (SD) | 19.2 (9.5) | 20.4 (9.1) | 0.23 |
 HOOS-12 Pain, mean (SD) | 32.9 (17.3) | 38.7 (18.9) | 0.05 |
 HOOS-12 Function, mean (SD) | 38.5 (20.2) | 46.0 (20.4) | 0.02 |
 HOOS-12 Quality of life, mean (SD) | 24.3 (18.3) | 30.8 (19.3) | 0.03 |
 HOOS-12 Summary, mean (SD) | 31.9 (16.3) | 38.5 (17.9) | 0.02 |
 EQ-5D-5L utility score, mean (SD) | 0.30 (0.40) | 0.30 (0.40) | 0.18 |
 EQ VAS, mean (SD) | 63.9 (21.9) | 65.9 (20.4) | 0.39 |
 Expected joint pain in 6 months, mean (SD) | 2.0 (2.9) | 1.6 (2.6) | 0.22 |
 Expected health in 6 months, mean (SD) | 86.4 (14.7) | 87.3 (14.8) | 0.63 |
 Expected mobility in 6 months, n (%) |  |  | 0.55 |
  No problems | 49 (74) | 11,760 (71) |  |
  Slight problems | 11 (17) | 3,565 (22) |  |
  Moderate problems | 3 (5) | 785 (5) |  |
  Severe problems | 2 (3) | 270 (2) |  |
  Unable to do | 1 (2) | 80 (1) |  |