Table 2.
Association between Health-Related Quality of Life and Mortality. Estimates based on Cox Proportional Hazard Regression. The outcome risk score (ORS) model includes socio-demographic variables, labs, medical prescriptions, dialysis treatment parameters and comorbidities. We added KDQoL-36 scales to the initial ORS model individually. BKD, burden of kidney disease; SKD, symptoms of kidney disease; EKD, effects of kidney disease; PCS, physical composite score; MCS, mental composite score; KSS, Kidney Disease Scale, a summary score derived from the 24 disease specific items of the KDQoL-36
| Model | Concordance Index | Coefficient Estimate | Mean QoL Score | SD QoL Score | Hazard Ratio (HR)* | p-value Coefficient |
|---|---|---|---|---|---|---|
| ORS | 0.7489 | - | - | - | - | - |
| ORS + BKD | 0.7495 | -0.0009 | 38.2 | 26.3 | 0.9885 | n.s. |
| ORS + SKD | 0.7530 | -0.0093 | 73.5 | 17.2 | 0.9232 | < 0.05 |
| ORS + EKD | 0.7574 | -0.0098 | 58.5 | 22.6 | 0.8952 | < 0.05 |
| ORS + PCS | 0.7540 | -0.0227 | 36.4 | 10.7 | 0.8857 | < 0.05 |
| ORS + MCS | 0.7453 | -0.0174 | 44.9 | 11.6 | 0.9038 | < 0.05 |
| ORS + KSS | 0.7542 | -0.0083 | 57.0 | 18.5 | 0.9258 | < 0.05 |
*HR = exp(SD/2*Coefficient Estimate). SD: standard deviation; ORS: Outcome Risk Score; BKD, burden of kidney disease; SKD, symptoms of kidney disease; EKD, effects of kidney disease; PCS, physical composite score; MCS, mental composite score; KSS, Kidney Disease Scale, summary score derived from the 24 disease specific items of the KDQoL-36