Complex Covariate Model

Full population model with multiple covariates, IIV, correlations, and residual error.

Model

CL = CL_pop × (WT/70)^0.75 × (CrCL/100)^0.5 × θ_sex^SEX × exp(η_CL)
V  = V_pop × (WT/70)^1.0 × exp(η_V)
Ka = Ka_pop × exp(η_Ka)

Where:
- η ~ MVN(0, Ω)  with correlation between η_CL and η_V
- ε ~ N(0, σ²)   residual error

Covariates

Covariate	Effect On	Type	Value
Weight	CL, V	Power	0.75, 1.0
CrCL	CL	Power	0.5
Sex	CL	Categorical	0.85 (female)

Omega Matrix (with correlations)

        CL    V     Ka
CL   [ 0.09  0.02  0    ]
V    [ 0.02  0.04  0    ]
Ka   [ 0     0     0.16 ]

Correlation CL-V ≈ 0.33