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Table 5 Ability of the Instruments to discriminate between individuals on the basis of self-rated health

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

  Self-rated General Health Comparison of Means   ROC Absolute Performance Gain
Instruments Poor health (n = 54) Good health (n = 168) 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 0.32 0.20 0.52 0.21 -1.00 0.20 -6.4 1.00 **0.76 0.69 0.83 Reference    
Independent living 0.67 0.22 0.80 0.19 -0.69 0.20 -4.4 0.48 **0.68 0.60 0.77 1.05 15.8 1.1 30.4
Social relationships 0.76 0.21 0.85 0.17 -0.53 0.18 -3.4 0.29 **0.67 0.59 0.75 1.14 17.8 2.4 33.1
Physical senses 0.89 0.10 0.91 0.09 -0.23 0.09 -1.4 0.05 0.56 0.47 0.64 ^2.06 40.6 21.3 59.9
Psychological wellbeing 0.66 0.17 0.80 0.13 -0.98 0.14 -6.3 0.97 **0.79 0.72 0.86 -0.38 5.7 -9.2 20.7
SF-36                
Physical function 26.6 17.7 40.8 22.4 -0.66 21.4 -4.3 0.44 **0.69 0.62 0.77 0.79 14.0 -3.4 31.3
Role physical 5.6 15.1 31.1 38.8 -0.74 34.6 -4.7 0.55 **0.69 0.61 0.76 0.79 15.1 -3.7 34.0
Bodily pain 24.8 14.0 43.7 18.1 -1.10 17.2 -7.0 1.21 **0.80 0.73 0.87 -0.46 7.4 -8.4 23.3
Vitality 28.8 18.0 50.3 19.5 -1.12 19.2 -7.2 1.26 **0.78 0.72 0.85 -0.25 4.2 -12.5 21.0
Social function 51.9 21.5 69.8 27.1 -0.69 25.8 -4.4 0.48 **0.70 0.63 0.78 0.71 11.4 -4.4 27.2
Role emotional 24.7 39.0 64.0 42.7 -0.94 41.8 -6.0 0.89 **0.73 0.66 0.81 0.28 5.4 -13.2 23.9
Mental health 54.7 17.4 70.6 18.7 -0.86 18.4 -5.5 0.75 **0.74 0.67 0.81 0.25 4.3 -12.8 21.4
PCS 25.3 5.6 32.4 9.2 -0.84 8.5 -5.4 0.71 **0.74 0.67 0.81 0.26 4.9 -1.4 23.4
WOMAC                
Pain 57.6 17.9 41.8 20.2 0.81 19.7 5.2 0.65 **0.73 0.65 0.80 0.41 7.2 -10.1 24.5
Stiffness 64.8 18.0 49.0 18.8 0.85 18.6 5.4 0.72 **0.72 0.65 0.80 0.41 7.6 -10.4 25.6
Physical function 59.6 15.5 43.1 19.7 0.88 18.8 5.6 0.77 **0.74 0.67 0.81 0.23 3.9 -12.5 20.4
WOMAC score 59.6 15.0 43.3 18.5 0.92 17.6 5.9 0.84 **0.75 0.68 0.82 0.13 2.1 -14.3 18.5
VAS (over past week)                
Average pain -62.3 21.0 -46.4 23.2 -0.70 22.7 -4.5 0.49 **0.69 0.61 0.77 0.75 13.6 -4.3 31.4
Pain at rest -45.3 21.7 -28.0 21.8 -0.79 21.8 -5.1 0.63 **0.72 0.65 0.80 0.43 7.8 -10.0 25.7
ADL Restriction -54.7 23.5 -39.6 25.5 -0.60 25.1 -3.8 0.36 **0.66 0.59 0.74 1.11 19.4 2.3 36.6
  1. N = 222, * All significant < 0.001 except Physical senses, p = 0.15.
  2. #Note: For the effect size calculations the poor health group was nominated as the 'control group'.