Individual-level coefficients represent the predicted parameter values for each
subject in the study. For models with factors, these coefficients combine:
The baseline intercept effect (fixed + random)
The factor-specific effect (fixed + random) for each factor level
This is equivalent to manually calculating:
coefficient = intercept_fixed + intercept_random + factor_fixed + factor_random
The function automatically handles:
Models with or without factors
Any number of factor levels
Missing random effects (defaults to 0)
Complex factor structures with multiple factors
For models without factors, only intercept coefficients are calculated.
For models with factors, both intercept and factor-level coefficients are provided.