Table V.
Parameter estimates for the longitudinal bidimensional item response theory model
| Parameter | Value |
|---|---|
| BaselineV (voiding scale) | − 0.0251 |
| BaselineS (storage scale) | − 0.0667 |
| PmaxV (maximal placebo response voiding scale) | − 0.75 |
| PmaxS (maximal placebo response storage scale) | − 0.845 |
| TprogV (placebo half-life voiding scale) | 12.9 |
| TprogS (placebo half-life storage scale) | 13.4 |
| Weibull shape parameter (common for both scales) | 1.53 |
| Drug effect voiding scale | − 0.488 |
| Drug effect storage scale | − 0.749 |
| Interindividual variability (IIV) | |
| IIV Baselinev (voiding scale) | 97.3% |
| IIV BaselineS (storage scale) | 128.8% |
| IIV Baselinev-BaselineS correlation | 26% |
| IIV Pmax (common for both scales) | 145.6% |
| IIV Tprog (common for both scales) | 61.1% |
| IIV Drift (common for both scales) | 0.6% |
| IIV Pmax-Drift correlation | 40% |