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Table 5 Predictors of SF12-physical (PCS) and SF12-mental (MCS) for the knee and hip datasets (multiple linear regression models)

From: Outcomes following large joint arthroplasty: does socio-economic status matter?

  PCSKnee MCSKnee PCSHip MCSHip
Variables Coefficient (95% CI) p Coefficient (95% CI) p Coefficient (95% CI) p Coefficient (95% CI) p
Female sex −1.20 (−2.56:0.15) 0.08 −0.19 (−1.59:1.21) 0.79 0.01 (−1.43:1.45) 0.99 −1.47 (−2.90:-0.04) 0.04
Age (years) −0.06 (−0.14:0.02) 0.13 0.11 (0.03:0.19) 0.005 −0.12 (−0.21:-0.02) 0.02 0.07 (−0.02:0.17) 0.12
SES score 0.05 (−0.18:0.29) 0.65 −0.28 (−0.52:-0.04) 0.02 0.13 (−0.12:0.39) 0.30 −0.15 (−0.40:0.10) 0.25
BMI −0.06 (−0.17:0.04) 0.24 −0.01 (−0.12:0.09) 0.79 −0.11 (−0.24:0.01) 0.08 0.02 (−0.11, 0.14) 0.81
Prosthesis type§ −1.16 (−2.25:0.07) 0.04 −0.99 (−2.12:0.13) 0.08 - -
Cemented prosthesis$ - - 0.75 (−0.98:2.46) 0.40 −0.12 (−1.82:1.58) 0.89
Complication −2.76 (−4.23:-1.30) < 0.0001 −1.60 (−3.11:0.10) 0.04 −1.31 (−2.93:0.30) 0.11 −0.39 (−1.99:1.20) 0.63
Non-English speaking −1.23 (−2.96:0.49) 0.16 −1.60 (−3.37:-0.18) 0.08 −0.77 (−3.10:1.55) 0.51 −0.44 (−2.73:1.86) 0.71
Age-adjusted CCI* 0.72 (−1.01:-0.42) < 0.0001 −0.36 (−0.67:-0.06) 0.02 0.92 (−1.28:-0.57) < 0.0001 −0.54 (−0.89:-0.19) 0.002
Pre-op KSSPain −0.04 (−0.12:0.04) 0.35 0.03 (−0.05:0.11) 0.43 - -
Pre-op KSSFunction ** 0.07 (0.03:0.11) < 0.0001 −0.00002 (−0.04:0.04) 1.00 - -
Pre-op HHSPain # - - −0.17 (−0.33:0.001) 0.048 −0.04 (−0.20:0.13) 0.67
Pre-op HHSFunction ¢ - - 0.14 (0.04:0.23) 0.004 −0.09 (−0.18:0.004) 0.06
Pre-op PCS§ 0.43 (0.32:0.54) < 0.0001 0.07 (−0.04:0.18) 0.20 0.35 (0.21:0.50) < 0.0001 0.14 (0.001:0.28) 0.049
Pre-op MCS 0.16 (0.11:0.22) < 0.0001 0.36 (0.31:0.42) < 0.0001 0.20 (0.13:0.26) < 0.0001 0.35 (0.28:0.41) < 0.0001
  1. Abbreviations: SES score Socioeconomic status score, BMI Body Mass Index, CCI Charlson Comorbidity Index, pre-op pre-operative, post-op post-operative, IKSS Pain International Knee Society Pain Score, IKSS Function International Knee Society Function Score, HHS Pain Harris Hip Pain Score, HHS Function Harris Hip Function Score, SF12 Physical Short Form 12 physical component, SF12 mental Short Form 12 mental component.
  2. SES score – Socioeconomic status score, (0 to 10) with a higher score representing socioeconomic advantage.
  3. BMI - Body Mass Index (weight [Kg]/height [m]2).
  4. §Coefficient relates to posterior stabilizing or ultra-congruent procedure (compared with cruciate retaining).
  5. $Coefficient relates to cemented (hybrid or totally cemented) compared with uncemented hip replacement.
  6. *CCI – Charlson Comorbidity Index (0–43, age adjusted), with a higher score indicating a greater comorbidity burden.
  7. KSSPain – Knee Society Pain Score (0 to 50) with a higher score representing less pain.
  8. **KSSFunction – Knee Society Function Score (0 to 100) with a higher score representing better function.
  9. #HHSPain – Harris Hip Pain Score (0 to 44) with a higher score representing less pain.
  10. ¢HHSFunction – Harris Hip Function Score (0 to 47) with a higher score representing better function.
  11. §PCS - score of ≥ 50 indicates no impairment; 40–49 mild impairment; 30–39 moderate impairment; and < 30 severe impairment.
  12. MCS - score of ≥ 50 indicates no distress; 40–49 mild distress; 30–39 moderate distress; and < 30 severe distress.
  13. Bold numbers denotes statistical significance (p < 0.05).