Table 5.
Ability of the Instruments to discriminate between individuals on the basis of self-rated health
| 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 |
N = 222, * All significant < 0.001 except Physical senses, p = 0.15.
#Note: For the effect size calculations the poor health group was nominated as the 'control group'.