Table 2.

Growth model parameter estimates

MeasureFixed-Effects Parameter EstimatesP Value for Model Fit (Wald)
Change over TimeDialysis InitiationAgeComorbidityKPS ScoreSexPropensity ScoreConstant
SF-36
 Mental health0.12±0.32a−0.69±5.80.21b−3.09a −0.430.682.6850.7b±6.2<0.001
 Physical health0.04±0.170.49±1.7−0.16b 1.61−1.21b−0.35−4.0421.1b±4.4<0.001
SWLS0.02±0.11−1.84a±4.50.12b −2.70a−0.350.71−0.1423.5b±5.5<0.001
HADS
 Depression−0.03±0.10−0.57±1.7−0.10b1.170.29b−0.810.025.56b±3.1<0.001
 Anxiety−0.004±0.14−0.02±2.6−0.020.730.53b0.10−0.785.36b±2.5<0.001
  • Unless otherwise noted, values are expressed as mean ± SD. Change over time (growth) for the fixed effect is the estimated change per month in the quality-of-life measure. Similar interpretations can be applied to dialysis initiation and the constant. Age, comorbidity, KPS score, sex, and propensity score were entered into the model as fixed effects only to adjust for variation between groups at baseline. SDs for age, comorbidity, KPS score, sex, and propensity score were not estimated because of constraints on model fitting. KPS, Karnofsky performance scale; SF-36, quality-of-life assessment using Short-Form 36 questionnaire; HADS, Hospital Anxiety and Depression Scale; SWLS, Satisfaction with Life Scale.

  • a P<0.05.

  • b P<0.01.