The population model
Vancomyzer uses the published Colin 2019 two-compartment population model for its supported adult intermittent intravenous vancomycin workflow. Age, total body weight and serum creatinine inform the starting estimates. Measured vancomycin concentrations can then inform Bayesian parameter estimation.
Dose history, sample timing, parameter bounds and error assumptions affect the result. A separate Vancomyzer policy limits fitted clearance using a Cockcroft–Gault-derived estimate. This is an implementation choice, not a Colin model coefficient.
Body size and clinical interpretation
The model applies its documented body-weight relationships. At BMI 40 kg/m² and above, the calculator advises early measured levels because published evaluation at that body size is limited. Fat-free mass and alternative creatinine-clearance estimates are displayed for context; they do not replace the population model's weight and creatinine relationships.
Use of the same population model across adult body sizes does not establish equal predictive performance in every subgroup. Review the supported inputs, assumptions and exclusions before evaluating a result.
Evidence and limitations
Vancomyzer has not completed independent clinical validation. Developer-run numerical checks and synthetic cases help detect implementation errors, but do not demonstrate accuracy in real patients or improved clinical outcomes.
Independent evaluation requires a fixed software version, a prespecified analysis plan and verified dose and sample histories. Body-size and renal-function subgroups need explicit reporting, including failed fits and unsupported cases.
See the current methods and calculator equations.
Reference
Colin PJ, et al. Vancomycin pharmacokinetics throughout life: results from a pooled population analysis and evaluation of current dosing recommendations. Clinical Pharmacokinetics. 2019;58:767–780. Published article.