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Table 6 WOMAC-Index and associated patients’ characteristics and clinical conditions: multivariable generalised estimating equation models

From: Quality of life outcomes in patients undergoing knee replacement surgery: longitudinal findings from the QPro-Gin study

WOMAC–Index Total (n = 132) Rehabilitation program after discharge
Yes (n = 40) No (n = 92)
β 95%CI P β 95%CI P β 95%CI P
Intercept 31.45 20.71,42.18 < 0.001 32.70 11.44,53.95 0.003 30.19 19.50,40.87 < 0.001
Time (3-months after surgery) −19.66 −31.77,-7.55 0.002 −10.48 −37.13,16.17 0.441 −20.65 −32.82,-8.49 0.001
Age ≥ 65 years −3.94 −9.71,1.84 0.181 −1.69 − 13.80,10.43 0.785 −4.46 −11.10,2.17 0.188
Time*Age ≥ 65 years 4.23 − 2.87,11.34 0.243 4.43 −8.65,17.51 0.507 3.46 −4.87,11.79 0.416
Female sex 10.18 4.48,15.89 0.001 6.12 −5.56,17.80 0.304 12.67 6.15,19.19 < 0.001
Time*Female sex −4.74 −11.10,1.63 0.145 − 1.66 − 15.31,11.99 0.811 −7.73 − 14.59,-0.87 0.027
Low education 3.65 −1.65,8.95 0.177 12.28 1.41,23.14 0.027 0.12 −5.85,6.09 0.969
Time*Low education 3.88 −2.99,10.74 0.269 −2.92 −15.18,9.35 0.641 7.47 0.09,14.84 0.047
BMI ≥ 30 kg/m2 4.58 −0.41,9.58 0.072 7.95 −2.66,18.56 0.142 5.70 0.13,11.27 0.045
Time*BMI ≥30 kg/m2 −5.97 −11.78,-0.16 0.044 −13.46 −25.23,-1.69 0.025 −6.44 −13.08,0.21 0.058
Depressive symptoms 11.47 5.03,17.92 0.001 11.90 −0.78,24.59 0.066 11.01 4.45,17.58 0.001
Time*Depressive symptoms −2.69 −9.85,4.48 0.463 −3.57 −17.73,10.59 0.621 −3.66 −11.65,4.33 0.370
Cognitive impairment −3.02 −10.51,4.47 0.429 −3.52 −21.32,14.27 0.698 −3.90 −12.73,4.93 0.387
Time*Cognitive impairment −7.64 −15.42,0.13 0.054 −18.53 −42.57,5.50 0.131 −3.78 − 12.21,4.65 0.380
Comorbidity ≥ 4 diseases −1.69 −7.15,3.76 0.543 −0.66 −12.25,10.94 0.912 −0.34 −6.43,5.76 0.914
Time*Comorbidity ≥4 diseases −2.77 −9.56,4.01 0.423 − 9.64 −22.00,2.73 0.127 −2.69 −10.52,5.13 0.500
Current smoker −2.40 −10.67,5.87 0.569 −22.79 −44.47,-1.11 0.039 1.58 −5.61,8.77 0.666
Time*Current smoker −2.29 −11.62,7.04 0.630 25.41 9.20,41.61 0.002 −7.55 −16.24,1.14 0.089
Current alcohol user −2.19 −8.02,3.64 0.462 −6.98 −18.46,4.50 0.233 −2.62 −8.41,3.16 0.374
Time*Current alcohol user 5.09 −2.28,12.47 0.176 6.69 −9.03,22.41 0.404 6.28 −1.18,13.75 0.099
TKA surgery 9.86 4.51,15.22 < 0.001 9.71 −2.02,21.44 0.105 11.11 5.60,16.63 < 0.001
Time*TKA surgery −6.33 −12.82,0.17 0.056 −8.20 −21.54,5.15 0.229 −7.03 −14.11,0.04 0.052
  1. Abbreviation: β, coefficient regression, CI confidence intervals, WOMAC Western Ontario and McMaster Universities Arthritis Index, BMI Body Mass Index, TKA total knee arthroplasty (reference UKA, unicompartmental knee arthroplasty)
  2. WOMAC-Index is normalised to 100, ranges from 0 [best] to 100 [worst]