Table 1

Demographic characteristics of preintervention and postintervention groups (hip)

CharacteristicPre-WCIS
(n=2397)
Post-WCIS
(n=2282)
P value
(pre vs post)
HipKneeHipKneeHipKnee
Total procedures104713509091373 0.0040 0.7285
Female (n, %)
(0.0007% knee data missing)
602 (57.5)851 (63.0)472 (51.9)833 (60.8) 0.0135* 0.221*
Mean age, year (SD)
(0.0002% data missing)
68.8 (13.5)66.7 (10.2)65.6 (11.8)66.5 (9.7) < 0.00010.572†
Mean BMI (SD)
(78.3% data missing)
30 (6.7)32.8 (7.5)30 (6.3)33.3 (8.1)0.720†0.717†
Mean pre-operative Oxford hip score (SD) (range: 12–60)
(47.4% data missing)
44.3 (8.4)41.5 (8.3)45.1 (7.9)42.3 (7.8)0.0889† 0.008†
Mean pre-operative PCS (SD) (range: 0–100)
(54.7% data missing)
29 (8.8)31 (8.5)28.8 (8.4)30.1 (8)0.681† 0.0203†
Mean pre-operative MCS (SD) (range: 0–100)
(54.7% data missing)
49.6 (12.5)51.3 (11.8)48.5 (12.5)50.5 (12)0.109†0.126†
Presence of a medical comorbidity (n, %)
(38% hip/29% knee data missing)
511 (87.1)857 (90.1)629 (99.2)979 (100) <0.0001‡ <0.0001‡
Presence of an MSK comorbidity (n, %)
(33% hip/30% knee data missing)
577 (99.8)907 (99.5)733 (100)1005 (99.9)0.441‡0.108‡
  • Missing data reported where missing; where not reported, data were not missing.

  • Oxford hip and knee scores: range 12 (best) to 60 (worst).

  • PCS-12—short form-12 physical component summary: range 0 (worst) to 100 (best).

  • MCS-12—short form-12 mental component summary: range 0 (worst) to 100 (best).

  • Medical comorbidities (0=no, 1=yes; reflective of 13 conditions).

  • Medical comorbidities: heart disease, high blood pressure, lung disease, diabetes, ulcer or stomach disease, kidney disease, liver disease, anaemia or other blood disease, cancer, depression, osteoarthritis or degenerative arthritis other than hip or knee, back pain, rheumatoid arthritis, other medical problem.

  • MSK comorbidities (0=no, 1=yes; indicated using a homunculus): right and/or left neck, shoulder area, elbow/forearm, wrist/hand, hip, thigh, knee area, calf area, ankle/foot area, back of neck, upper back and lower back.

  • Bold values indicate p<0.05.

  • *P value calculated using χ2 test.

  • †P value calculated using Student’s t-test.

  • ‡P value calculated using Fisher’s exact test.

  • MCS, mental component summary; PCS, physical component summary; WCIS, Winnipeg Central Intake Service.