Governing Equations

Mixed-Effects Model (NLME):
  CL_i = TV_CL · (WT_i/70)^θ · exp(η_CL,i)
  V_i = TV_V · exp(η_V,i)
  η ~ N(0, ω²)

VPC (Visual Predictive Check):
  5th, 50th, 95th percentiles of simulated data
  compared to observed percentiles

Shrinkage:
  Shrinkage = 1 - SD(η_posterior) / ω
  Shrinkage > 25% → unreliable individual estimates

RSE (Relative Standard Error):
  RSE = SE(parameter) / parameter_estimate · 100%
  RSE < 30% acceptable for structural parameters

Covariate Model:
  CL = θ1 · (WT/70)^θ2 · (CrCl/100)^θ3 · exp(η1)