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Table 3 Ability of the instruments to discriminate between OWL patients and community group

From: Parsimonious and efficient assessment of health-related quality of life in osteoarthritis research: validation of the Assessment of Quality of Life (AQoL) instrument

  Waiting List v Community Comparison of Means   ROC Absolute
Performance Gain
Instruments Community
(n = 111)
OWL
(n = 45)
Effect size # SD. t RE Area Under Curve Asymptotic 95% CI Z APG % 95% CI
  M SD. M SD       Lower Upper    Lower Upper
AQOL                
    Utility Score 0.50 0.19 0.37 0.25 0.66 0.21 3.7** 1.00 **0.67 0.57 0.77 reference    
   Independent living 0.80 0.18 0.69 0.22 0.58 0.19 3.3** 0.79 *0.66 0.57 0.75 0.10 1.9 -16.6 20.5
   Social relationships 0.84 0.15 0.76 0.26 0.24 0.19 2.4* 0.41 0.56 0.45 0.67 1.08 21.5 1.9 41.1
   Physical senses 0.90 0.09 0.92 0.07 -0.26 0.08 -1.4 0.16 0.43 0.33 0.53 ^1.97 48.5 24.4 72.7
   Psychological wellbeing 0.81 0.11 0.67 0.23 0.88 0.15 4.9** 1.78 *0.65 0.54 0.76 0.22 4.4 -15.2 23.9
SF-36                
   Physical function 40.8 21.0 29.8 24.9 0.50 22.2 2.8* 0.57 **0.67 0.57 0.77 -0.02 0.5 -22.7 23.8
   Role physical 26.7 37.1 10.6 22.9 0.48 33.7 2.7* 0.53 *0.61 0.52 0.70 0.47 11.6 -12.3 35.5
   Bodily pain 42.7 18.8 33.9 17.2 0.48 18.3 2.7* 0.53 *0.63 0.53 0.72 0.43 8.8 -11.1 28.7
   General health 56.6 22.2 51.7 20.8 0.22 21.8 1.3 0.12 0.56 0.47 0.66 0.86 21.1 -3.0 45.2
   Vitality 44.7 19.5 43.3 22.0 0.07 20.2 0.4 0.01 0.52 0.42 0.63 1.22 29.4 5.8 53.1
   Social function 68.4 24.8 56.4 28.7 0.46 26.0 2.6* 0.49 *0.62 0.52 0.72 0.46 9.8 -11.2 30.9
   Role emotional 55.1 44.6 43.0 45.9 0.27 45.0 1.5 0.17 0.57 0.47 0.67 0.81 19.9 -4.2 44.0
   Mental health 68.3 17.9 61.3 22.3 0.36 19.2 2.1* 0.30 0.59 0.48 0.69 0.69 16.5 -6.9 39.8
   PCS 31.8 9.3 27.8 8.1 0.44 9.0 2.5* 0.46 *0.64 0.55 0.74 0.20 5.0 -19.5 29.4
   MCS 47.8 11.6 44.9 13.4 0.24 12.1 1.4 0.13 0.56 0.46 0.66 0.91 21.4 -1.6 44.3
WOMAC                
   Pain 41.6 20.7 54.3 21.9 -0.60 21.0 -3.4** 0.84 *0.66 0.57 0.76 0.08 1.7 -20.3 0.2
   Stiffness 50.0 18.5 59.4 18.9 -0.51 18.6 -2.9* 0.60 *0.63 0.53 0.72 0.37 8.3 -13.5 0.3
   Physical function 42.5 19.4 58.5 19.3 -0.82 19.4 -4.7** 1.57 **0.71 0.62 0.80 -0.38 8.1 -12.8 0.3
   Total score 42.9 18.4 57.7 19.0 -0.79 18.6 -4.5** 1.46 **0.70 0.61 0.79 -0.28 6.0 -14.7 0.3
VAS (over past week)                
   Average pain -43.7 23.8 -60.7 21.6 0.74 23.2 4.2** 1.26 **0.70 0.61 0.79 -0.28 6.0 -0.2 0.3
   Pain at rest -26.9 22.2 -41.8 22.6 0.67 22.3 3.8** 1.03 **0.70 0.61 0.78 -0.22 5.0 -0.2 0.3
   ADL Restriction -37.8 26.0 -51.2 23.9 0.53 25.4 3.0* 0.64 *0.65 0.56 0.74 0.18 3.9 -0.2 0.3
  1. # Note: For the effect size calculations the Community group was nominated as the 'control group'. * p < 0.05, ** p < 0.001, ^ p > 0.05.